Browse Topic: Mathematical analysis

Items (253)

Enhancing Thermal Performance of Trapezoidal Porous Medium Solar Ponds: Experimental and Numerical Analysis

2025-28-0207To be published on 02/07/2025

This study investigates the thermal efficiency of trapezoidal porous medium solar ponds through a multifaceted approach encompassing laboratory experiments, outdoor contrasts, and numerical analysis. Laboratory experiments were conducted to evaluate the heat storage capabilities of various porous materials. Outdoor contrast experiments, involving two mini solar ponds with a surface area of 0.42m×0.42m and a bottom area of 0.09m×0.09m, examined the thermal performance enhancement offered by porous medium incorporation. Factors such as the presence of a cover and the type of porous medium were analyzed for their influence on temperature distribution. Results revealed a notable increase in the maximum temperature of the solar pond by approximately 10°C following the introduction of porous medium. Furthermore, numerical evaluation utilizing MATLAB provided deeper insights into the experimental data, enriching our understanding of the thermal dynamics specific to trapezoidal porous medium

J, Vinoth Kumar

Forced Vibration Analysis of Cracked Functionally Graded Beams

2025-28-0169To be published on 02/07/2025

This study investigates the forced vibration characteristics of functionally graded material (FGM) beams with square cross-sections featuring V-shaped cracks. FGMs, characterized by a gradual transition in mechanical composition from a ceramic to a metallic surface, offer unique advantages in various engineering applications due to their non-uniform microstructure, which imparts varying material properties throughout the structure. This research employs ANSYS Workbench to conduct a comprehensive numerical analysis, focusing on evaluating the frequencies and mode shapes of cracked FGM beams under simply supported boundary conditions. The analysis delves into the impact of three critical crack parameters: crack opening width, crack depth, and crack location. The findings highlight that the crack opening width significantly influences the vibrational frequencies of the FGM beam. Specifically, as the crack opening width increases from 0.002 meters to 0.01 meters, the frequencies decrease

D, Manish, C V, Prasshanth, N, Suhas, Bhaskara Rao, Lokavarapu

Numerical Analysis of Capillary Performance of Various Lattice Structures for Vapor Chamber Application

2025-28-0062To be published on 02/07/2025

Additive manufacturing has made it possible for the design of increasingly complex structures that require precise manufacturing. This may be particularly beneficial for heat pipe and vapor chamber design – particularly for the wick structure, a very important component. This study uses numerical simulation to analyze three different types of lattice structures of increasing complexity, in terms of their capillary performance. This is one of the most important parameters which determine the wick efficacy. Simple cubic, Column and Octet lattice models are computationally designed and CFD is used to simulate capillary action in a pipe of 0.4 mm inner radius for 2 milliseconds, after validation of the numerical model with existing experimental results. It is found that the Octet lattice (with the most complex inner structure) has the greatest capillary rise in the same amount of time. The rate of rise is not uniform for any structure, but is highest for Octet. This study demonstrates the

Sundararaj, Senthilkumar, Hudge, Ajay, Basuroy, Suhashini, Kang, Shung-Wen

A Modeling Methodology for the Analysis of Abradable Powder Piston Skirt Coatings

2024-01-3953

11/15/2024

Abstract Line2Line’s patented abradable powder surface coatings are a mechanism by which clearance between mating components is reduced, and the tribological properties of the interacting surfaces can be improved. The following discussion presents the modeling efforts targeting the numerical analysis of abradable powder piston skirt coatings. This study employs the Cylinder-Kit Analysis System for Engines (CASE) by Mid-Michigan Research to model the performance enhancements offered by abradable powder coatings as applied to piston skirts. Two piston models were generated for the purposes of this analysis, one with the post-run stock reference geometry and coating, as supplied by the manufacturer, and the second having the Line2Line post-run coated geometry. The pistons modeled had been installed within two separate Cummins R2.8 L turbo diesel engines, both of which were subject to several hours of runtime. The primary finding of the current study is that the Line2Line abradable powder

Nicklowitz, Daniel, Schock, Harold, Suman, Andy, Lowe, Jim, Wood, Ai LeGrande

SYSTEM DESIGN OF A VEHICLE STRUCTURE BY A NETWORK OF OPTIMIZATIONS

2024-01-3109

11/15/2024

ABSTRACT Vehicle design is a complex process requiring interactions and exchange of information among multiple disciplines such as fatigue, strength, propulsion, survivability, safety, thermal management, stealth, maintenance, and manufacturing. Simulation models are employed for assessing and potentially improving a vehicle’s performance in individual technical areas. The vehicle’s characteristics influence the performance in all the different attributes. Challenges arise when designing a vehicle for improving mutually competing objectives, satisfying constraints from multiple engineering disciplines, and determining a single set of values for the vehicle’s characteristics. It is of interest to engage simulation models from the various engineering disciplines in an organized and coordinated manner for determining a design configuration that provides the best possible performance in all disciplines. This paper presents an approach that conducts optimization analysis for a complex

He, Jim, Hart, Christopher G., Vlahopoulos, Nickolas

Stress Field near Crack Tips in Pressurized Thick-Walled Cylinders with Single and Multiple Cracks in Linear Elastic Fracture Mechanics: Analytical and Numerical Analysis of Stress Field and Crack Behavior

05-18-01-0004

10/04/2024

Arrays of radial cracks often appear at the bore of pressurized cylinders, posing potential safety risks and leading to possible structural failures. This article presents an analytical approach to evaluate the stress field arising from single or multiple uniform radial cracks in thick-walled pressurized cylinders within the context of linear elastic fracture mechanics (LEFM) under mode-I loading. This formulation is based on the fundamental equations of elasticity and approximations of stress intensity factors (SIF) reported in the literature. Hence, the SIF were revisited and their range of validity was highlighted. The study considers two types of internal pressure loading: one applied only to the cylinder’s inner surface with no pressure on the crack faces and another applied to both the inner surface and the crack faces. The influence of the number and length of cracks relative to cylinder thickness on the stress field is analyzed. A finite element model of the pressurized vessel

Methia, Mounir, Benslimane, Abdelhakim, Bechir, Hocine, Aït Hocine, Nourredine

Preliminary Analysis of the Energy Performance of a Mild Hybrid Vehicle with Focus on e-Motor Dynamic Modeling

2024-24-0012

09/18/2024

Nowadays, the increase in the global population and the rise in living standards lead to a growing number of cars on the roads, resulting in an increase in emissions. It becomes crucial for society to make efforts to modernize the entire vehicle fleet to emission standards adequate for combating climate change, accelerating the natural turnover of older vehicles whenever possible. For this reason, the following study delves into the category of mild hybrid electric vehicles, which can be easily obtained through retrofitting practices from existing vehicles, thus enabling the enhancement of a large number of cars using minimal materials and requiring minimal time. The present paper focuses on the performance of the traction electric machine, whose dynamic model - based on the equivalent circuit model of a surface synchronous permanent magnet electric motor - is shown to allow for an accurate representation of instantaneous power and efficiency during its operation. Still, this motor

Federici, Leonardo, Lombardi, Simone, Tribioli, Laura, Bella, Gino

Passenger Hypoxia Protection Utilizing Oxygen Enriched Gas Mixtures

AIR6036 (Current)

09/13/2024

Currently, existing civil aviation standards address the design and certification of oxygen dispensing devices that utilize oxygen sources supplying at least 99.5% oxygen. This Aerospace Information Report discusses issues relating to the use in the passenger cabin of oxygen enriched breathing gas mixtures having an oxygen content of less than 99.5% and describes one method of showing that passenger oxygen dispensing devices provide suitable hypoxia protection when used with such mixtures

A-10 Aircraft Oxygen Equipment Committee

Numerical Analysis of the Expansion–Deflection Dual-Bell Nozzle Performance

2024-01-6003

08/23/2024

The objective of this paper is to identify the optimum supersonic Mach number for expansion–deflection dual-bell nozzle. The numerical analysis is carried for expansion–deflection dual-bell nozzle (EDDBN) with different free stream conditions. Numerical study observes that the transition pressure ratio and Mach contours are studied through inside and outside of the nozzle. The results proved that increasing the Mach number leads to decrease in the static pressure as well as reduce the performance of EDDBN nozzle. The analysis was carried out for four different Mach number, out of which Mach number 1.2 provides the optimum results. In the present study, the influence of Mach number behavior affects the pressure and Mach configuration inside and outside of the EDDBN nozzle. This novel concept is used in supersonic vehicles for higher performances. Also, it provides a way to improve the existing nozzle design configuration

Balaji, K., Kalekar, Yashdeep, Naik, Atharva, Walave, Gurudas, Charapalle, Samruddhi

A Transient Numerical Analysis of a Dissipative Expansion Chamber Muffler

2024-01-2935

06/12/2024

Expansion chamber mufflers are commonly applied to reduce noise in heating, ventilation, and air-conditioning (HVAC) or exhaust systems. In dissipative mufflers, sound-absorptive materials, such as microperforated plates (MPP), are applied to achieve an enhanced and more broadband mitigation effect. Computational acoustics (CA) analyses of mufflers are usually carried out in the frequency domain, assuming time-harmonic excitation. However, certain applications require time-domain simulations. From a computational point of view, such transient analyses are more challenging. A transformation of the governing equations involving frequency-dependent material parameters into the time domain induces convolution integrals. We apply the recently proposed finite element (FE) formulation of a time-domain equivalent fluid (TDEF) model to simulate the transient response of dissipative acoustic media to arbitrary unsteady excitation. Like most time-domain approaches, the formulation relies on

Maurerlehner, Paul, Mayrhofer, Dominik, Mehrgou, Mehdi, Kaltenbacher, Manfred, Schoder, Stefan

SAE TOMORROW TODAY: Unsupervised Learning Makes Scalable Autonomy a Reality

1345906/12/2024

Artificial intelligence that teaches itself? That's the gist of unsupervised learning. And it offers far-reaching implications for the future autonomous driving--and much more. As a pioneer in unsupervised learning, Helm.ai employs an AI-first approach to building autonomous driving software using an in-house unsupervised learning technology called Deep Teaching which leverages insights from applied mathematics and compressive sensing. Deep Teaching enables Helm.ai to train on vast volumes of data more efficiently without the need for large scale fleets or human annotation, moving the world closer to fully autonomous self-driving systems. The company licenses their software to automakers for high-end ADAS L2+/L3 products and uses the same scalable AI approach for L2/L3 ADAS through L4. To learn more about this exciting breakthrough, we sat down with Vlad Voroninski, CEO & Co-Founder of Helm.ai, to discuss unsupervised learning, Deep Teaching, and the future of autonomous driving

Hineman, Marcie

Numerical Investigation of the Aerodynamic Characteristics of a Missile Geometry at Mach 4

2024-26-0443

06/01/2024

The aim of this paper is to present a numerical analysis of high-speed flows over a missile geometry. The N1G missile has been selected for our study, which is subjected to a high-speed flow at Mach 4 over a range of Angle of attack (AoA) from 0° to 6°. The analysis has been conducted for a 3-dimensional missile model using ANSYS environment. The study contemplates to provide new insights into the missile aerodynamic performance which includes the coefficient of lift (CL), coefficient of drag (CD) and coefficient of moment (CM) using computational fluid dynamics (CFD). As there is a lack of availability of data for missile geometries, such as free stream conditions and/or the experimental data for a given Mach number, this paper intends to provide a detailed analysis at Mach 4. As the technology is advancing, there is a need for high-speed weapons (missiles) with a good aerodynamic performance, which intern will benefit in reduction of fuel consumption. In order to meet the

Padmanabha, M Ananth, Prasad, Bhoomika, Sivasubramanian, Jayahar

Analysis for Effect of Angle of Attack on Coefficient of Lift of Wing Structure

2024-26-0450

06/01/2024

Dimensional optimization has always been a time-consuming process, especially for aerodynamic bodies, requiring much tuning of dimensions and testing for each sample. Aerodynamic auxiliaries, especially wings, are design dependent on the primary model attached, as they influence the amount of lift or reduction in drag which is beneficial to the model. This study aims to reduce the time period taken to finalize the design parameter for the same. For a wing, the angle of attack is essential in creating proper splits to incoming winds, even under high velocities with larger distances from the separation point. In the case of a group of wings, each wing is then mentioned as a wing element, and each wing is strategically positioned behind the previous wing in terms of its vertical height and its self-angle of attack to create maximum lift. At the same time, its drag remains variable to its shape ultimately maximizing the CL/CD ratio. A high value of CL indicates a significant component of

Hujare, Pravin P, Hujare, Deepak P, Choudhary, Prateek, Sakat, Abhishek, Karanjkar, Rushil

Numerical Analysis of Different Hydrogen Injector Characteristics in a Constant Volume Chamber

2024-01-2693

04/09/2024

Hydrogen is anticipated to play a pivotal role as a green energy carrier in both heavy industry and transportation. Utilizing hydrogen directly in internal combustion engines (ICE) could offer several advantages compared to alternative technologies. To achieve this objective, a proper understanding of the physical mechanisms and dynamics involved in the injection of this fuel is needed. This study applied high-fidelity computational fluid dynamics (CFD) simulations to describe the flow characteristics of hydrogen injection using hollow- and single- and multi-solid-cone injectors and their effect on mixing quality and characteristics in a constant volume quiescent environment. A reference hollow-cone configuration was used to validate the model. The results indicate that solid-cone configurations achieve greater penetration due to the flow patterns they generate. However, an increase in the number of holes leads to reduced penetration length, projected area, and induced turbulence

Moreno Cabezas, Kevin, Zaihi, Abdullah, Liu, Xinlei, Aljohani, Bassam, Wu, Hao, Ben Houidi, Moez, Roberts, William L., Im, Hong G.

A Numerical Analysis of Terrain and Vehicle Characteristics in Off-Road Conditions through Semi-Empirical Tire Contact Modelling

2024-01-2297

04/09/2024

In the last decades, the locomotion of wheeled and tracked vehicles on soft soils has been widely investigated due to the large interest in planetary, agricultural, and military applications. The development of a tire-soft soil contact model which accurately represents the micro and macro-scale interactions plays a crucial role for the performance assessment in off-road conditions since vehicle traction and handling are strongly influenced by the soil characteristics. In this framework, the analysis of realistic operative conditions turns out to be a challenging research target. In this research work, a semi-empirical model describing the interaction between a tire and homogeneous and fine-grained soils is developed in Matlab/Simulink. The stress distribution and the resulting forces at the contact patch are based on well-known terramechanics theories, such as pressure-sinkage Bekker’s approach and Mohr-Coulomb’s failure criterion. The force exerted by the soil on the sidewall of the

Zerbato, Luca, Vella, Angelo Domenico, Galvagno, Enrico, Vigliani, Alessandro, Data, Silvio, Sacchi, Matteo Eugenio

A Novel Approach for Mechanical Characterization of Angle-Ply Composite Laminates

2024-01-2435

04/09/2024

Composites made of continuous fibers generally have higher strength-to-weight ratios in fiber directions as compared to those made of discontinuous fibers. However, the latter tend to display quasi-isotropic properties which can be of advantage when directions of mechanical loading can vary. For many real-world applications such as robust design of vehicle body components for crashworthiness, impact loads are stochastic in nature both in terms of magnitude and direction. Hence, in order to realize the true potential of laminated composites with continuous fibers, instead of orthotropic laminates which are most common due to the ease of design and manufacturing, angle-ply laminates are necessary. The latter category of laminates introduce a high degree of flexibility in design options but are also simultaneously challenging in terms of mechanical characterization due to the presence of a larger number of material parameters, as compared to orthotropic laminates, with coupled normal and

Tanaya, Sushree, Deb, Anindya

Detecting the Anomalies in LiDAR Pointcloud

2024-01-2045

04/09/2024

LiDAR sensors play an important role in the perception stack of modern autonomous driving systems. Adverse weather conditions such as rain, fog and dust, as well as some (occasional) LiDAR hardware fault may cause the LiDAR to produce pointcloud with abnormal patterns such as scattered noise points and uncommon intensity values. In this paper, we propose a novel approach to detect whether a LiDAR is generating anomalous pointcloud by analyzing the pointcloud characteristics. Specifically, we develop a pointcloud quality metric based on the LiDAR points’ spatial and intensity distribution to characterize the noise level of the pointcloud, which relies on pure mathematical analysis and does not require any labeling or training as learning-based methods do. Therefore, the method is scalable and can be quickly deployed either online to improve the autonomy safety by monitoring anomalies in the LiDAR data or offline to perform in-depth study of the LiDAR behavior over large amount of data

Zhang, Chiyu, Han, Ji, Zou, Yao, Dong, Kexin, Li, Yujia, Ding, Junchun, Han, Xiaoling

Numerical Analysis of Mixing of Bio-Hybrid Fuels in a Direct Injection Engine with a Pre-Chamber Ignition System

2024-01-2619

04/09/2024

Numerical analyses of the liquid fuel injection and subsequent fuel-air mixing for a high-tumble direct injection engine with an active pre-chamber ignition system at operation conditions of 2000 RPM are presented. The Navier-Stokes equations for compressible in-cylinder flow are solved numerically using a hierarchical Cartesian mesh based finite-volume method. To determine the fuel vapor before ignition large-eddy flow simulations are two-way coupled with the spray droplets in a Lagrangian Particle Tracking (LPT) formulation. The combined hierarchical Cartesian mesh ensures efficient usage of high performance computing systems through solution adaptive refinement and dynamic load balancing. Computational meshes with approximately 170 million cells and 1.0 million spray parcels are used for the simulations. The influence of a lateral ethanol injection on the tumble flow motion and the entrainment into the pre-chamber is analyzed for stoichiometric and lean fuel conditions for an early

Wegmann, Tim, Meinke, Matthias, Fleischmann, Maximilian, Pischinger, Stefan, Schröder, Wolfgang

Design and Numerical Analysis of Double-Base Swirl Injector for Ethanol/Hydrogen-Peroxide Based Liquid Propellant Rocket Engine

2023-01-5100

02/23/2024

This paper presents a study of numerical cold flow analysis of double-base swirl injector design using Ansys Fluent. The study focuses on the design validation and development of double-base liquid-liquid swirl injector for Ethanol(Fuel) and Hydrogen Peroxide(Oxidizer) based liquid propellant rocket engine. The green propellant contains 80% Ethanol (C2H5OH) as fuel and 60% Hydrogen Peroxide (H2O2) as oxidizer. A comprehensive data, obtained from NASA CEARun code, of performance parameters and carbon monoxide and carbon dioxide emission of most commonly used propellant is compared with ethanol and hydrogen-peroxide based propellant is presented for reference. Secondly, the paper presents the theoretical design model of Swirl Injector, and numerical cold flow study of swirl injector model. For this the 3D models of fuel and oxidizer swirl nozzles are designed separately as per the theoretical design parameters. Poly-hexacore type fluent meshing is used to generate valid mesh. A 3-D

Kumar, G. Dinesh, Agarwal, Abishek Garg

Exploring the Mechanical and Morphological Characteristics of Hybrid-Reinforced Polymer Composites

2023-01-5181

02/23/2024

This study focuses on the development of a hybrid composite, incorporating natural fibers—specifically, banana and flax fibers—within a polyester resin matrix. Different volume ratios of banana and flax fibers were systematically employed to create the composite, with a particular emphasis on achieving optimal fabrication processes through compression molding. The mechanical properties of the resulting hybrid composite were comprehensively assessed through tensile, impact, and flexural testing using a Universal Testing Machine (UTM). Morphological analysis, facilitated by a Scanning Electron Microscope (SEM), provided insights into the internal structure of the composite. Additionally, numerical analysis utilizing ANSYS software was employed to further understand the composite's behavior. The findings unveiled that the hybrid composite demonstrated superior strength compared to single-fiber composites. This research contributes to advancing our understanding of hybrid composites

Velmurugan, Santhosh, Janakiraman, Thiagarajan, Nandhini, S., Ganesha Rathinam, M.

Numerical Analysis of Different Injectors for Kerosene/Hydrogen-Peroxide and Ethanol Amine/Hydrogen-Peroxide for Satellite Thruster

2023-01-5180

02/23/2024

In a satellite thruster the function of injector plays a major role in controlling the combustion. This paper presents the numerical simulation of two most used injectors namely, impinging doublet, and triplet using Ansys fluent. The injectors are designed for the non-toxic, green propellants used in satellite thrusters. The present study focuses on the design and simulation of the injectors with 2 variant of green propellants i.e., Kerosene/Hydrogen-peroxide and Ethanol Amine/Hydrogen-peroxide. The objective of the study is to investigate the performance of the two injectors in terms of atomization, combustion efficiency and thrust generation. Theoretical design calculations were performed for a 20 N bi-propellant satellite thruster. A comparative study on the condensed combustion products and injector was carried out using NASA CEA Run code and Ansys fluent, respectively. The ethanol amine/hydrogen-peroxide injector showed better performance in terms of combustion efficiency. The

Chidvilas, N.V., Suraj, V., Balaji, Kota, G., Dinesh Kumar

Thermal Management of an Automotive Headlamp

2024-26-0286

01/16/2024

These days, the use of virtual simulations through the Computational Fluid Dynamics (CFD) methodology is increasing exponentially during the development phase of an automotive headlamp. Thereupon, the automotive industries are becoming competent enough to build an ingenious and creative design with optimal performance within the coherent time. A considerable amount of heat is generated inside the headlamp when it is switched on for a longer time. Hence it becomes vital to reduce the risks if any during the development phase by providing an adequate thermal management strategy within the headlamp. The present study conducted an experimental analysis on an automotive headlamp to decide its thermal characteristics and behavior. Numerical analysis was also performed to determine the airflow and temperature distributions within a headlamp. This study also focuses on finding the main hotspot regions over the headlamp through virtual simulations. The methodology shows a consensus with the

Kolhe, Shailesh Madhukar

A Combined Experimental and Numerical Analysis on the Aerodynamics of a Carbon-Ceramic Brake Disc

15-17-02-0009

01/04/2024

Composite ceramic brake discs are made of ceramic material reinforced with carbon fibers and offer exceptional advantages that translate directly into higher vehicle performance. In the case of an electric vehicle, it could increase the range of the vehicle, and in the case of conventional internal combustion engine vehicles, it means lower fuel consumption (and consequently lower CO2 emissions). These discs are typically characterized by complex internal geometries, further complicated by the presence of drilling holes on both friction surfaces. To estimate the aerothermal performance of these discs, and for the thermal management of the vehicle, a reliable model for predicting the air flowing across the disc channels is needed. In this study, a real carbon-ceramic brake disc with drilling holes was investigated in a dedicated test rig simulating the wheel corner flow conditions experimentally using the particle image velocimetry technique and numerically. The simulation was performed

Rouina, Samaneh, Barigozzi, Giovanna, Abdeh, Hamed, Palomino Solis, Daniel A., Iavarone, Paolo

Numerical Analysis and Optimization of Heat Transfer for FSAE Radiator for Various Sidepod Designs

2023-28-0055

11/10/2023

Heat transfer optimization is a crucial aspect of the design process for Formula Student race cars, particularly for the radiator, usually housed in a side pod. For the car to operate at peak performance, a well-designed radiator-sidepod system is essential such that it can dissipate heat generated by the engine faster, for the car to run in optimal performance. Testing the car physically for various radiator-sidepod design iterations is a very difficult task, also considering the costs to manufacture the radiator-sidepod setup. The objective of this study is to develop a comprehensive methodology for analysing heat transfer through radiator setup using Computational Fluid Dynamics and to validate it through experimental investigations, to enhance performance and efficiency of the radiator setup. It further explains how to find out its heat transfer efficiency, and to choose the right radiator-sidepod setup, giving optimal performance. The flow of coolant inside the radiator, as well

Suresh, Sankar, Sundar, Mahima, Bhaskara Rao, Lokavarapu

Research on Injection Characteristics of Marine Ammonia Fuel Injector under Wide Temperature Range

2023-01-7017

10/30/2023

Ammonia fuel is typically characterized by low viscosity, low flash point, and non-flammability. This means that fuel characteristics and operational requirements significantly deviate from those of conventional fuels, requiring a significant technical upgrade to the existing fuel supply and injection systems. This research involves a numerical analysis of ammonia utilization in high-pressure direct injection. Considering the non-isothermal compressibility of the fuel flow process, the fluid properties in the model are specifically defined based on the physical properties of the ammonia fuel. The injection performance of ammonia fuel was studied, including comparing the injection performance of ammonia fuel with conventional diesel fuel under typical operating conditions in the injector, and exploring the injection characteristics of ammonia fuel injector under a wide fuel temperature range. The results of ammonia injection indicate that the response characteristics of liquid ammonia

Li, Meisi, Fan, Liyun, Wei, Yunpeng, Mao, Yuntao

A Study of the Mechanism of High-Speed Knocking in a Two-Stroke SI Engine with High Compression Ratio

2023-01-1824

10/24/2023

Experimental methods and numerical analysis were used to investigate the mechanism of high-speed knocking that occurs in small two-stroke engines. The multi-ion probe method was used in the experiments to visualize flame propagation in the cylinder. The flame was detected by 14 ion probes grounded in the end gas region. A histogram was made of the order in which flames were detected. The characteristics of combustion in the cylinder were clarified by comparing warming up and after warming up and by extracting the features of the cycle in which knocking occurred. As a result, regions of fast flame propagation and regions prone to auto-ignition were identified. In the numerical analysis, flow and residual gas distribution in the cylinder, flame propagation and self-ignition were visualized by 3D CFD using 1D CFD calculation results as boundary conditions and initial conditions. Flame propagation calculated by 3D CFD was found to be directional due to in-cylinder flow caused by scavenging

Eto, Kuniyoshi, Kuboyama, Tatsuya, Moriyoshi, Yasuo, Yamada, Toshio, Yatsufusa, Tomoaki, Suzuki, Yusuke

Experimental and Numerical Analysis of an Outward Opening Injector Pintle Dynamics

2023-01-1810

10/24/2023

Direct injection strategies have been successfully used on spark ignited internal combustion engines for improving performance and reducing emissions. Among the different technologies available, outward opening injectors seem to have found their place in renewable applications running on gaseous fuels, including natural gas or hydrogen, as well as in a few specific liquid fuel applications. In order to understand the key operating principles of these devices, their limitations and the resulting sprays, it is necessary to accurately describe the pintle dynamics. The pintle’s relative position with respect to the injector body defines the internal flow geometry and therefore the injection rates and spray characteristics. In this paper both numerical and experimental investigations of the dynamics of an outward opening injector pintle have been carried out. The injector average flow rates and instantaneous pintle position have been experimentally measured at a variety of pressures and

Eguiluz, Rodrigo, Stover, Luke, Powell, Tommy, Costa, Tiago, Kopache, Alexander, Hartman, Peter, Hwang, Joonsik, Shkolnik, Alexander

Numerical Analysis on the Characteristics of the Pressure Wave Generation Initiated by the Onset of the Auto-Ignition in the End-Gas

2023-01-1804

10/24/2023

The end-gas auto-ignition and associated pressure wave generation in a premixed gas with a spatial distribution is numerically investigated. This study assumes that the auto-ignition phenomenon in the end-gas of PCCI combustion, a next-generation combustion method which is expected to achieve both low fuel consumption and low emissions at a high level. Detailed numerical analysis considering the chemical kinetics on the one-dimensional compressible fluid flow with high spatial and time resolution was performed to clarify the detailed phenomena of the auto-ignition and onset of the pressure wave and its propagation in the end-gas. Followings are results. (1) The pressure wave generations related with the auto-ignition in the end-gas is categorized into two types. The cases that the auto-ignition velocity, which is the localized auto-ignitive propagation velocity relative to the unburned mixture, exceeded the local sound speed, or not. The spatial distribution of the equivalence ratio in

YOSHIDA, Kenji

Numerical Analysis and Modelling of the Effectiveness of Micro Wind Turbines Installed in an Electric Vehicle as a Range Extender

14-13-02-0010

10/10/2023

In recent years, the number of electric vehicles (EVs) has grown rapidly, as well as public interest in them. However, the lack of sufficient range is one of the most common complaints about these vehicles, which is particularly problematic for people with long daily commutes. Thus, this article proposed a solution to this problem by installing micro wind turbines (MWTs) on EVs as a range extender. The turbines will generate electricity by converting the kinetic energy of the air flowing through the MWT into mechanical energy, which can have a reasonable effect on the vehicle aerodynamics. The article uses mathematical modelling and numerical analysis. Regarding the modelling, a detailed EV model in MATLAB/SIMULINK was developed to analyze the EV performance using various driving cycles in real time. In terms of numerical analysis, a detailed computational fluid dynamics (CFD) model has been implemented on a sample EV (Kia Soul) and an MWT using the Moving Reference Frame (MRF) method

Ebaid, Munzer, Shahin, Zin Al Abdin A. E., Alshawabkeh, Mohammad M. D.

A Study on Combustion and Emission Characteristics of Ammonia, Hydrogen and Diesel Tri-Fuel Engines

2023-32-0103

09/29/2023

Ammonia is a promising alternative to conventional fossil fuels for internal combustion engines, especially in the maritime industry, because it does not emit carbon dioxide. Since redundancy is important in marine engines, a dual fuel system with diesel oil is currently widely applied to use alternative fuels such as liquefied natural gas, and a similar system is expected for ammonia-fueled ships. However, ammonia has low ignitability and low burning speed, hence improvement of combustion efficiency is major challenge. In addition, the emission of N2O which has a high global warming effect is also problematic as well as emission of NOX as air pollutant. To overcome these challenges, a mixing with hydrogen, which has high ignitability and high burning speed, can be effective. Therefore, in this study, combustion and emission characteristics of tri-fuel combustion engines, in which ammonia and hydrogen-air mixture is ignited by μ-pilot injection of diesel oil, were investigated

Matsunaga, Daichi, Tentora, Takafumi, Hiraoka, Kenji, Toshinaga, Kazuteru

Experimental and Numerical Analysis on Combustion Characteristics of Ammonia and Diesel Dual Fuel Engine

2023-32-0102

09/29/2023

Ammonia is well known as one of the promising substitute energy sources for fossil fuels, but it has some disadvantages such as low ignitability and low burning speed. Co-combustion with diesel fuel can compensate for its disadvantages and enable the application of the ammonia as a main fuel for internal combustion engines. In this study, the effects of ammonia/diesel mixing ratio and excess air ratio on combustion and emission characteristics have been investigated by internal combustion engine test and numerical approach. In the engine test, it was found that the ammonia/diesel mixing ratio and excess air ratio have a large effect on the heat release rate and emissions of nitrogen monoxide, nitrogen dioxide, unburned ammonia, and nitrous oxide. High ammonia mixing ratio leads to the aforementioned emissions, but these emissions were reduced in stoichiometric conditions compared to lean conditions. To investigate engine experimental results, the ammonia/n-heptane co-combustion

Hiraoka, Kenji, Matsunaga, Daichi, Kamino, Takafumi, Honda, Yusuke, Toshinaga, Kazuteru, Murakami, Yuki, Nakamura, Hisashi

Development of film heat transfer model based on multiphase flow numerical analysis

2023-32-0012

09/29/2023

Automobiles will have to be applied strict regulations such as Euro7 against PM, HC, CO. The generation of these components are related to fuel deposition to the wall surface of the combustion chamber. Therefore, the fuel injection model of engine combustion CFD requires accurate prediction about the deposition and vaporization of fuel on the combustion chamber. In this study, multiphase flow numerical analysis that simulates fuel behavior on the wall surface was conducted first. Then, two model formulae about the contact area and the heat flux of a liquid film was constructed based on the result of multiphase flow numerical analysis method. Finally, the new film heat transfer model was constructed from these model formulae. In addition, it was confirmed that new heat transfer model can predict the liquid film temperature obtained by multiphase flow numerical analysis method accurately

Nagasawa, Takeshi, Uchida, Kenji, Yamashita, Hiroyuki

Visualization of Physical / Thermal Evaporation Phenomena with Experimental and PIV-DDM Analysis in Urea-SCR Dosing System of Multi-Phase Flow

2023-32-0098

09/29/2023

This study was visualized by experimental and numerical analysis for the unknown injected droplet phenomena with the multi-phase flow in the Urea-SCR dosing system. Visualization experiments were conducted on the droplet behavior inside the pipe with simulated urea SCR injection system. Although the total number of droplets decreases at gas temperatures of 150°C and 200°C, a significant number of injected droplets remained at the position corresponding to the SCR catalyst. That is physical kinetic energy was found to dominate over thermal evaporation. However, the impingement of droplets into the pipe wall had occurred complex behavior by physical/thermal evaporation, and these droplets weren't on gas airflow at the lower part of the pipe. Furthermore, these actual phenomena were reflected in experimental coefficients for new reduction model analysis instead of CFD

NOHARA, Tetsuo, SUGIYAMA, Naoki, NARA, Shotaro, ONO, Jyo, ONOUE, Hiroki, OSADA, Rina, KAWAMOTO, Yuki, OCHIAI, Masayuki, TAKAHASHI, Shun, OOSUMI, Kazuo, ISHIKAWA, Naoya

Experimental and Numerical Analysis of a Swirled Fuel Atomizer for an Aftertreatment Diesel Burner

2023-24-0106

08/28/2023

Emission legislation for light and heavy duty vehicles is requiring a drastic reduction of exhaust pollutants from internal combustion engines (ICE). Achieving a quick heating-up of the catalyst is of paramount importance to cut down cold start emissions and meet current and new regulation requirements. This paper describes the development and the basic characteristics of a novel burner for diesel engines exhaust systems designed for being activated immediately at engine cold start or during vehicle cruise. The burner is comprised of a swirled fuel dosing system, an air system, and an ignition device. The main design characteristics are presented, with a detailed description of the atomization, air-fuel interaction and mixture formation processes. An atomizer prototype has been extensively analyzed and tested in various conditions, to characterize the resulting fuel spray under cold-start and ambient operating conditions. The geometrical shape of the spray was investigated by imaging

Postrioti, Lucio, Battistoni, Michele, Zembi, Jacopo, Brizi, Gabriele, La Sana, Marco, Brignone, Mauro, Napoli, Francesco, Pizza, Salvatore, Milani, Emanuele

Snow Effects on the NGCTR Nacelle for Relevant Certification Conditions

2023-01-1373

06/15/2023

This paper is focused on the numerical analysis of the impingement and water catch rate of snow particles on the engine air intake of the Next Generation Civil Tilt Rotor (NGCTR). This NGCTR is developed by Leonardo Helicopters. The collection efficiency and water catch rate for the intake geometry are obtained for the test cases that have been defined for the relevant snow conditions. These conditions are related to the flight envelope of the NGCTR, existing EASA/FAA certification specifications, and the snow characterization. The analyses have been performed for the baseline air intake geometry. A range of particle diameters has been simulated with a particle density equal to the density of ice and with a particle drag relation that disregards the particle shape. Based on the results for the water catch rate on the basic nacelle configuration in snow conditions it is concluded that the ‘cheeks’ of the duct are more susceptible to impingement of larger snow crystals (>75 μm), whereas

Kool, Nina, Van der Weide, Edwin, Spek, Ferdinand, van der Ven, Harmen, van 't Hoff, Stefan

In Flight Ice Shape Prediction with Data Fit Surrogate Models

2023-01-1480

06/15/2023

Accurate simulation of icing is important for the assessment of several potential icing scenarios and complex icing regulations. However, performing all possible icing scenarios is a demanding process in terms of computational cost, especially when modification of the geometry due to ice accretion is required. Additionally, aircraft icing safety assessment necessitates an evaluation of the accumulated ice. Thus, numerical representation of the non-linear and complex geometries is essential for the parametrization of this ice. Indeed, surrogate models have the capability of predicting these complex, non-linear shapes. For this purpose, a method for ice accretion prediction on a selected airfoil, NACA 22112, is proposed in this study with different surrogate models that will later be used for fast prediction in 6DOF simulations to directly evaluate its effects on aerodynamic performance during flight. The required datasets in order to train for clean and iced airfoils are based on

Akbal, Omer, Ayan, Erdem, Murat, Canibek, Ozgen, Serkan

Numerical Simulation of the Effect of a Centripetal Wing Spoiler on the Flow Aerodynamics of a Sports Car

2023-01-5032

06/01/2023

This study presents a numerical analysis of the flow around an Audi R8 sports car and the effect of adding a National Advisory Committee for Aeronautics (NACA) 6412 base profile wing. The mass and momentum conservation laws are solved using Reynolds-averaged Navier–Stokes (RANS) equations. The turbulence is simulated using the realizable k–ε model, and the pressure–velocity coupling is solved using the semi-implicit method for pressure-linked equations (SIMPLE). The analysis was performed in the ANSYS Fluent-19 numerical code. The numerical results were validated with experimental data and numerical simulations from other studies in the open literature on vehicles without wings. The analyses included quantifying drag, lift, lateral forces, and their respective coefficients. When the wing was attached to the rear of the vehicle, there was a considerable increase in the aerodynamic load with an increase in drag. Therefore, the wing used in this study represented an effective balance of

Zavala, David, Vicente, William, Esquivel, Ruben, Salinas-Vazquez, Martin

Numerical Analysis of Lightweight Materials and their Combinations to Understand their Behaviour against High Pressure Shock Loading

2023-28-1311

05/25/2023

Materials play a key role in our day to day life and have shaped the industrial revolution to a great extent. Right selection of material for meeting a particular objective is the key to success in today’s world where the cost as well as sustainability of any equipment or a system have assumed greater significance than ever before. In automotive industry, materials have a definitive role as far as the mobility and safety is concerned. Materials that can absorb the required energy or impact can be manufactured through different manufacturing as well as metallurgical processes which involves appropriate heat treatment and bringing correct chemical compositions etc. However, they can also be formed by simpler methods such as combining certain materials together in the form of layered combinations to form light weight composites. Analyzing the response of different materials during incidents such as high-speed impact or transmission of shock waves as a result of earthquakes, tsunami or

Singh, Swati, Chauhan PhD, R. S., Sandhu PhD, Inderpal Singh, Sharma PhD, Prince

Numerical Analysis of Wind Noise Transmission through BEV Underbody

2023-01-1119

05/08/2023

In electrified automobiles, wind noise significantly contributes to the overall noise inside the cabin. In particular, underbody airflow is a dominant noise source at low frequencies (less than 500 Hz). However, the wind noise transmission mechanism through a battery electric vehicle (BEV) underbody is complex because the BEV has a battery under the floor panel. Although various types of underbody structures exist for BEVs, in this study, the focus was on an underbody structure with two surfaces as inputs of wind noise sources: the outer surface exposed to the external underbody flow, such as undercover and suspension, and the floor panel, located above the undercover and battery. In this study, aero-vibro-acoustic simulations were performed to clarify the transmission mechanism of the BEV underbody wind noise. The external flow and acoustic fields were simulated using computational fluid dynamics. The vehicle structural vibration and sound fields of the interior and exterior cabin

Washizu, Tomoya, Fukushima, Tadayoshi, Hirose, Kenichi, Taniguchi, Keiichi, Oshima, Munehiko, Miyakawa, Takayuki, Enomoto, Toshio

A Process to Characterize the Sound Directivity Pattern of AVAS Speaker

2023-01-1095

05/08/2023

Speaker performance in Acoustic Vehicle Alerting System (AVAS) plays a crucial role for pedestrian safety. Sound radiation from AVAS speaker has obvious directivity pattern. Considering this feature is critical for accurately simulating the exterior sound field of electrical vehicles. This paper proposes a new process to characterize the sound directivity pattern of AVAS speaker. The first step of the process is to perform an acoustic testing to measure the sound pressure radiated from the speaker at a certain number of microphone locations in a free field environment. Based on the geometry of a virtual speaker, the locations of each microphone and measured sound pressure data, an inverse method, namely the inverse pellicular analysis, is adopted to recover a set of vibration pattern of the virtual speaker surface. The recovered surface vibration pattern can then be incorporated in the full vehicle numerical model as an excitation for simulating the exterior sound field. In this study

Yang, Wenlong, Wang, Chong, Zhang, Qijun

Analysis and Optimization of Metallic Based Substrates for After-Treatment System by Means of Full-Scale CFD Simulations and Experiments

2023-01-0369

04/11/2023

The tightening trend of regulations on the levels of admitted pollutant emissions has given a great spur to the research work in the field of combustion and after-treatment devices. Despite the improvements that can be applied to the development of the combustion process, pollutant emissions cannot be reduced to zero; for this reason, the aftertreatment system will become a key component in the path to achieving near-zero emission levels. This study focuses on the numerical analysis and optimization of different metallic substrates, specifically developed for three-way catalyst (TWC) and Diesel oxidation catalyst (DOC) applications, to improve their thermal efficiency by reducing radial thermal losses through the outer mantle. The optimization process relies on computational fluid dynamics (CFD) simulations supported by experimental measurements to validate the numerical models carried out under uncoated conditions, where chemical reactions do not occur. Full-scale three-dimensional

Sartirana, Andrea, Montenegro, Gianluca, Della Torre, Augusto, Onorati, Angelo, Pace, Lorenzo, Zaldua-Moreno, Naroa

Model-Based Design of Controlled Suspension Incorporating Ride Comfort Sensory Performance Model for Vibration during Vehicle Driving

2023-01-0175

04/11/2023

The aim of this study was to build a model-based design tool that allows multidisciplinary teams to design vehicle performance targets using an easily understandable common index during the conceptual design phase of vehicle ride comfort performance. The newer a system is in the conceptual design stage without a prototype, the more difficult it is to describe its performance and impact on the vehicle. The originality of this study lies in the proposal of an understandable design tool for the social implementation of new technology, referred to as the multidisciplinary optimization (MDO) and “1DCAE” design concept. More specifically, the subject is the conceptual design of a unique electronically controlled damper system. A model-based development tool was developed, and numerical analysis was performed based on the following approach. A sensory performance model was constructed using a function that relates the acceleration RMS value of the vehicle body to a 10-point sensory evaluation

Kikuchi, Hironobu, Inaba, Kazuaki

Quantitative Multi-Physics Tools for Automotive Wiper Design

2023-01-0602

04/11/2023

The primary function of automotive windscreen wipers is to remove excess water and debris to secure a clear view for the driver. Their successful operation is imperative to vehicle occupants’ safety. To avoid reliance on experimental testing there is a need to develop physics-based models that can quantify the effects of design-based decisions on automotive wipers. This work presents a suite of evaluative tools that can provide quantitative data on the effects of design decisions. We analyse the complex non-linear contact interaction between the wiper blade and the automotive screen using finite element analysis, assessing the impact of blade geometry on the contact distribution. The influence of the evolution of normal applied load by the wiper arm is also investigated as to how it impacts the contact distribution evolution. The dynamics of the blade are subsequently analysed using a multiple connected mass spring damper system. Additionally, we apply hydrodynamic lubrication theory

Graham, Bradley, Knowles, James, Mavros, George

Numerical Analysis of Armored Fighting Vehicle Escape Hatch Subjected to Mine Blast Loading Using Coupled Eulerian-Lagrangian Technique

05-16-03-0017

03/30/2023

This article describes the research work taken to compare the effect of air blast and surface-buried mine blast loading on an armored fighting vehicle (AFV) escape hatch, using the coupled Eulerian-Lagrangian (CEL) technique. Two types of escape hatch were considered for the study, namely, the flat plate version and double-side curved-plate version. To evaluate the research methodology used in this investigation, initially, a published experimental work on a circular plate subjected to air blast was chosen and a benchmark simulation was carried out using the CEL technique to establish the simulation procedure. Then the established procedure was utilized for further analysis. It was observed that the variation in the deformation between the published literature and the simulation work was well within the acceptable engineering limits. After that, numerical studies were conducted on the flat and double-side curved hatch by subjecting it to both air blast and surface-buried mine blast

Parthasarathy, Sundaresan, Kumar, J. Rajesh

Numerical Analysis of Battery Thermal Management System Using Passive Cooling Technique

2023-01-0990

03/07/2023

Nowadays electric vehicle is replacing internal combustion engines in the transport sector. The growth of electric vehicles is increasing rapidly to reduce the impact of global warming and climate change. The battery limits the use of electric vehicles as an exact alternative to traditional IC engine vehicles. Specifically, the operating temperature, charge/discharge rates, and internal heat generation of the battery the performance of electric vehicles, like the driving range, charge storage capacity, the cycle life of the battery, and thermal runaway occurring at high temperatures. To overcome these problems, the battery thermal management system (BTMS) controls the temperature of the battery and maintains the optimal temperature to operate the battery efficiently and safely. In the heights of the above facts, the numerical analysis of 18650 Li-ion battery thermal management systems by passive cooling technology using Phase Change Material (PCM). The recent developments in battery

Joshi, Anand K., Dandotiya, Devendra, Ramesh, C. S., Panchal, Satyam

Numerical Analysis for Three Types of Wings at Various Angles of Attack: A Comparative Study

2023-01-5012

02/14/2023

The proper design procedure is a critical factor that restricts the capacity of an unmanned aerial vehicle (UAV) to fly freely for long periods. A UAV could fly with a high lift force and less drag if the aerodynamic performance of the wings is taken into account. With the aim to identify the best configuration that provides a high aerodynamic ratio (L/D) at low flying speeds, the current study investigates single-taper wings with three different configurations (conventional, dihedral, and polyhedral). This is achieved by applying the fundamentals of sailplanes to the single-taper wing planform in this study. Various attacking angles from 0° to 15° were tested in the research using a high-lift low-speed airfoil, the AG-16, and a constant low Reynolds number of 3 × 105. SOLIDWORKS software was used to model the wings under investigation, while ANSYS Fluent software was used to run the simulation. All of the examples under study used the same mesh type, number of elements, and operating

Al-Zaini, Essam Oun Ali, Mutaib, Ali H., Abboud, Zainab

Pressure Drop and Heat Transfer Analysis of Power Battery Liquid Cooling System

2022-01-7122

12/16/2022

The battery liquid cooling system can ensure that the battery works within a suitable temperature range, improve the safety performance of the battery system, and ensure the cruising range. This paper introduces a design scheme of a stamped double-parallel liquid cooling plate. Based on the STAR-CCM+ simulation software, a thermal simulation model of the battery management system is established to analyze the thermal behavior of the battery system and to study the effect of the inlet mass flow rate on the temperature of the top surface of the batteries. At the same time, with the analysis of the proportion of pressure drop of each component in the liquid cooling plate, an optimization of inserted part in the liquid cooling plate is proposed. The numerical analysis results are compared with the experimental results of the pressure drop to improve the effectiveness of the optimization scheme. When the pump head is constant, the pressure drop of the liquid cooling plate is reduced to

Liu, Zhien, Xie, Miao, Lu, Chihua, Pei, Shuqing

Numerical Analysis of Wind-Break Fences for Truck Stability in Crosswind

02-16-02-0011

10/04/2022

Several accidents on the highways are due to strong crosswind conditions. The effectiveness of wind-break fences on a sudden strong crosswind has been investigated for a generic truck model. Two wind-break fences have been designed for stretching the rise time of aerodynamic loads. The dynamic response of the vehicle to crosswind while exiting a tunnel is simulated. Moving mesh CFD simulations and vehicle dynamics simulations are used to assess the effectiveness of the fences based on a safety index and the maximum lateral displacement of the vehicle. The proposed fences mitigate sudden aerodynamic loads and avoid the rollover of the vehicle

Semeraro, Francesco Fabio, Cioffi, Antonio, Pellegrino, Emanuele, Schito, Paolo, Vignati, Michele

Research on the Longitudinal Dynamics of an Electric Scooter

10-07-01-0003

09/23/2022

The segment of micro-vehicles has experienced an increasing spread in recent years since its positive implications for both individual road users and the whole urban scenario. An experimental and numerical analysis on a standing electric scooter (e-scooter) is proposed with the aim of evaluating the longitudinal performance and the influence of rider positioning on the dynamics of the whole system; for this purpose, an e-scooter available in Europe and at mid-range price is considered. The vehicle is instrumented to monitor its longitudinal position, velocity, and acceleration. Test procedure and data processing are defined to homogeneously acquire and manage the signals. The experimental campaign is divided into three main categories corresponding to different maneuvers, i.e., acceleration, braking, and coasting. Specific attention is given to the electric motor modalities, both in driving and regeneration; moreover, the dependency of the rolling resistance force on tire inflation

Vella, Angelo Domenico, Vigliani, Alessandro

Development of Brake Squeal Noise Robustness Index and Improve Noise Tuning Efficiency Using Friction Induced Modal

2022-01-1177

09/19/2022

NVH is one of the important factors in automobile development. Brake squeal noise, in particular, is an important indicator of perceived quality of automobile. Squeal noise, one of the most difficult factors in automobile brake development, is noise caused by the complex interaction of friction characteristics, caliper behavior, frequency characteristics and environmental conditions. Therefore, it is not easy to come up with an effective improvement plan in a short time. The purpose of this study is to develop a new evaluation method to improve the squeal noise of the brake caliper system and to select the FIM index, which is the standard for objective numerical analysis. The newly developed Friction Induced Modal Method is an evaluation method that uses an inertia noise dynamometer to control the environment and braking conditions in the same way as the squeal noise conditions generated in the field, and to analyze the NVH characteristics of brake calipers. In conclusion, measurement

Lee, Junwon, Choi, Juhyun, Baek, Myoungjin, Yoon, Taewook, Yoon, Kyuwon

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