Direct water injection inside the cylinder is a promising technique to enhance the upper load limit and reduce nitrogen oxides emissions. The advantage of water injection depends on the percentage of water evaporated inside the cylinder. The percentage of water evaporation depends upon the water injection parameters. Hence, a computational fluid dynamics analysis is done to determine the effect of water injection temperature, water spray cone angle, nozzle hole diameter, and number of nozzle holes on in-cylinder distribution and percentage of water evaporation, engine performance, and emissions of a homogeneous charge compression ignition engine. This analysis considers water injection temperature from 295 K to 385 K, water spray cone angle from 8° to 24°, nozzle hole diameter from 0.14 mm to 0.205 mm, and number of nozzle holes from 4 to 7. The computational fluid dynamics models used are validated from the available experimental data in the literature for the engine considered. Here

Naik, Bharat, Mallikarjuna, J. M.

Computational Modeling of Aerodynamic Design Trends for a Production SUV Subjected to Incremental Design Changes: Roof Spoiler and Underbody Geometry

15-18-01-0006

11/21/2024

In this work, we evaluated computational fluid dynamics (CFD) methods for predicting the design trends in flow around a mass-production luxury sport utility vehicle (SUV) subjected to incremental design changes via spoiler and underbody combinations. We compared Reynolds-averaged Navier–Stokes (RANS) using several turbulence models and a delayed detached eddy simulation (DDES) to experimental measurements from a 40% scale wind tunnel test model at matched full-scale Reynolds number. Regardless of turbulence model, RANS was unable to consistently reproduce the design trends in drag from wind tunnel data. This inability of RANS to reproduce the drag trends stemmed from inaccurate base pressure predictions for each vehicle configuration brought on by highly separated flow within the vehicle wake. When taking A-B design trends, many of these errors compounded together to form design trends that did not reflect those measured in experiments. On the other hand, DDES proved to be more

Aultman, Matthew, Disotell, Kevin, Duan, Lian, Metka, Matthew

NOVEL HPC CONSIDERATIONS FOR ADVANCED CFD

2024-01-3202

11/15/2024

ABSTRACT This paper examines the current state of scalable CFD for high-performance computing (HPC) clusters at industry-scale, and provides a review of novel technologies that can enable additional levels of CFD parallelism beyond today’s conventional approach. Recent trends in HPC offer opportunities for CFD solution performance increases from the use of parallel file systems for parallel I/O, and a second level of solver parallelism through hybrid CPU-GPU co-processing

Posey, Stan

A HYBRID REDUCED ORDER MODELING APPROACH FOR RAPID TRANSIENT THERMAL SIMULATION AND SIGNATURE ANALYSIS

2024-01-3921

11/15/2024

ABSTRACT This paper presents a hybrid CFD and reduced order modeling (ROM) approach for fast and accurate flow and thermal analysis of vehicles to enable rapid thermal signature prediction. The modular hybrid ROM solver includes several key components, such as the turbulence modeling, CFD full order model (FOM) customized for vehicle thermal analysis, FOM/ROM alternation, proper orthogonal decomposition (POD) for basis vector construction, and online model switch decision maker for coupled simulation, which are all developed in an integrated framework. Several case studies of Army relevance at increasing complexity levels are undertaken. The proposed hybrid ROM solver is able to accurately analyze flow, turbulence, and thermal phenomena under time-varying operating conditions with unprecedented computational performance. Quantitatively, the relative error of our hybrid CFD FOM/ROM simulation stays below 0.35% and the absolute error is less than 4 K. The ROM has a much smaller model

Wang, Yi, Krolick, William C., Kaminsky, Andrew L., Tison, Nathan, Ruan, Yeefeng, Korivi, Vamshi, Pant, Kapil

Thermographic Detection of Near and Far-Side Corrosion

2024-01-3734

11/15/2024

ABSTRACT Active thermography has been demonstrated to be an effective tool for detection of near-surface corrosion hidden under paint, as well as hidden material loss due to corrosion. Compared to established point inspection techniques (e.g. ultrasound, eddy current), thermography offers fast, wide-area inspection of flat or curved surfaces that does not require direct contact or coupling. In its simplest form, it can be used to perform qualitative inspection using a heat gun or lamp and an uncooled IR camera. Recent developments in thermographic signal processing, coupled with improved IR camera and thermal excitation technology have resulted in significant advances in resolution, sensitivity and probability of detection of near and far-surface corrosion, and the ability to perform quantitative characterization of corrosion

Shepard, Steven, Beemer, Maria

Coupled CFD-Thermal Analysis

2024-01-3218

11/15/2024

ABSTRACT The both CFD (Computational Fluid Dynamics) and thermal analyses are used to predict a vehicle system thermal performance during the design development. The vehicle wall temperatures and compartments temperatures under various climatic conditions are predicted in MuSES thermal analyses. The temperature and air flow distributions inside the vehicle compartment are predicted in Star CCM+ CFD analyses. Recently, GDLS, Thermal Analytics, and CD-adapco jointly developed a CFD thermal analysis panel. This panel can be used to apply all boundary conditions to MuSES model and StarCCM+ CFD model by a few button clicks. It can map convection coefficients predicted in CFD analysis to the MuSES model boundaries; and vise versa, map wall temperatures and heat rates predicted in MuSES models to the boundaries in StarCCM+ models. Using this panel, the MuSES analysis and StarCCM+ analysis can be coupled to predict vehicle thermal performance with higher accuracy. Besides, most model inputs

Pang, Jing

Amphibious Vehicle Water Egress Modeling and Simulation Using CFD and Wong’s Methodology

2024-01-3805

11/15/2024

ABSTRACT A significant challenge for wheel- and propeller-driven amphibious vehicles during swimming operations involves the egress from bodies of water. The vehicle needs to be able to swim to the ramp of a vessel, and then propel itself up the ramp using water propellers and wheels simultaneously. To accurately predict the ability of the vehicle to climb the ramp, it is important to accurately model: (1) the interaction of the flow through the propellers, around the vehicle hull, and away from the ramp; (2) the wheel / ramp interaction; (3) the suspension system spring, damping, and motion-limiting forces, tire deformation and loading characteristics, and wheel and hull motions (both translation and rotation); and (4) the drivetrain power distribution to the wheels. Detailed modeling and simulation of these physics and processes -- such as the wheel, hull, and suspension system motions and force interactions, propeller rotation and resulting flow, etc. -- would be highly

Tison, Nathan

EXPLORATION OF OIL FLOW AND HEAT TRANSFER PHENOMENON FOR GALLERY-COOLED DIESEL ENGINE PISTONS

2024-01-4017

11/15/2024

ABSTRACT This paper details the exploration of oil jet piston cooling phenomenon with a focus on heat transfer from the diesel engine piston to the oil. Several numerical methods based on computational fluid dynamics (CFD) and conjugate heat transfer (CHT) were developed to resolve key aspects of piston oil cooling. These methods aim to establish and characterize the flow and heat transfer regimes that are inherent to the piston gallery cooling system, and to assist in quantifying the piston heat transfer and establish its dependence on a number of parameters related to the engine layout and performance, the oil cooling system, and the cooling gallery contained within the piston. Telemetry experimental data from a single-cylinder diesel engine was used to better understand the piston cooling system and to develop and validate modeling and simulation approaches. The combined findings offer a foundation for further study of oil jet piston cooling. Citation: A. Grunin. V. Korivi, “Oil

Grunin, Arkady, Korivi, Vamshi

AUGMENTING THERMAL AND SIGNATURE MODELS USING A FAST 3D FLUID DYNAMICS SIMULATION FOR IMPROVED CONVECTION FIDELITY

2024-01-4023

11/15/2024

ABSTRACT Accuratet thermal simulations for the purpose of thermal or infrared signature management require accurate representation of all modes of heat transfer. For scenarios with complex fluid dynamics and convective heat transfer, traditional options have included very simple 0D methods or very computationally expensive 3D CFD simulations. Motivated by adding options between these extremes and tuning the method to a heat transfer focus, a 3D fluid dynamics solver is developed that is tightly integrated and automatically coupled with the MuSES thermal and EO/IR simulation software. Key applications of interest include wind flow around ground vehicles for the purpose of infrared signature management and HVAC air flow within cabins for the purpose of thermal management. The flow solver uses novel numerical techniques to simplify the standard Navier-Stokes equations and avoid calculations which may not be necessary for thermal simulations. Several domain meshing strategies, physics

Pryor, Joshua, Karnitz, Duncan, Powers, Warren, Banyai, Douglas, Rynes, Pete, Tison, Nathan, Korivi, Vamshi, Ruan, Yeefeng

TIME DEPENDENT SIMULATION METHODS FOR VEHICLE THERMAL MANAGEMENT

2024-01-3106

11/15/2024

ABSTRACT Increasing power requirements along with weight and space constrains requires implementation of more intelligent thermal management systems. The design and development of such systems can only be possible with a thorough understanding of component and system level thermal loads. The present work implements 1-D and 3-D unsteady CFD based simulation tools in vehicle design process. Both under-the-hood cooling and HVAC systems are simulated in various operating conditions on a HPC Computer Cluster. System variables are optimized with gradient based BCSLIB and SciPy optimization libraries. The simulation results are compared and validated with experimental tests

Bayraktar, Ilhan

Liquid Cooling for Next Generation Rugged COTS Modules

2024-01-3389

11/15/2024

ABSTRACT High power/performance electronic modules are challenging the ability of air cooling to successfully remove the generated heat. Single phase liquid cooling is a proven approach for effective cooling of large amounts of heat, and has been deployed on defense platforms. Determining the thermal performance of liquid cooled cold plates can be done with basic spreadsheet calculations. These calculations can be sufficiently accurate for first order thermal analyses of design options, which enables rapid trade-off studies. To demonstrate this, a sample spreadsheet is introduced and compared to computational fluid dynamics (CFD) analyses, as well as empirical results

Straznicky, Ivan

MACHINE LEARNING-BASED THERMAL AND FLOW SIMULATION ON HETEROGENEOUS PLATFORM FOR SIGNATURE PREDICTION

2024-01-3922

11/15/2024

ABSTRACT The data-driven machine learning (ML) method is developed to rapidly evaluate the thermal and flow fields of a ground vehicle and its neighboring environment at various conditions. The artificial neural network (ANN) is implemented as the ML model to evaluate the fields, while achieving equivalent accuracy as the CFD simulations. In order for ANN to precisely map a relationship between the simulation parameters and the solution field, the proper orthogonal decomposition (POD) technique is applied to reduce the dimension of the field variables. Consequently, the compressed data (i.e. modal coefficients) is selected as the target for the ANN. Once trained, POD reconstruction is performed on the ANN predicted modal coefficients to recover the CFD solution. The developed framework is tested at diverse sample sites, and the maximum mean absolute errors are found to be 0.41 K and 0.019 m/s for thermal and flow simulations, respectively, verifying the outstanding prediction

Hong, Seong Hyeon, House, Alec, Kaminsky, Andrew L., Tison, Nathan, Ruan, Yeefeng, Korivi, Vamshi, Wang, Yi, Pant, Kapil

A METHODOLOGY TO PREDICT TRANSIENT ENGINE COMPARTMENT AIR TEMPERATURE FOLLOWING ENGINE SHUT DOWN

2024-01-3230

11/15/2024

ABSTRACT Cooling and heat protection of the engine compartment significantly impact the performance of combat vehicles. An increased heat load occurs during soak-back after engine shut down, where the fans are shut down. Heat is transferred from the hot components in the engine compartment by natural convection to the surrounding air and by radiation to the armor. The heat is then dissipated to the ambient mostly by convection from the outside surfaces. The objective of this study is to develop a methodology to predict the engine compartment airflow velocity and temperature distributions, as well as the surface temperature of critical engine components following engine shut down. This study was conducted using a full-scale, mock-up engine compartment of a typical wheeled combat vehicle under steady-state and transient operating conditions. The Computational Fluid Dynamics (CFD) package Fluent was used to conduct the simulation. Steady-state simulation was performed first to predict the

AbdulNour, Bashar, Battoei, Mohsen, Doroudian, Mark

EVALUATION OF JP-8 SURROGATE UNDER SPRAY DIESEL CONDITIONS USING DETAILED CHEMICAL KINETIC MODELS

2024-01-3431

11/15/2024

ABSTRACT Single-Fuel Concept (SFC) describes the desire to operate diesel engines using JP-8 as the only fuel in the US military due to mostly logistic reasons. However, there is a lack of a fundamental database on the combustion characteristics of JP-8 compared to those studies that have been done for diesel combustion. In this current study, several kinetic models are used to look into flame properties including ignition behavior, fuel properties including evaporation characteristics, and species evolution such as soot precursor, acetylene. Several surrogates for JP-8 fuel including tetradecane, n-dodecane and a mixture of 77 vol-% n-dodecane and 23 vol-% m-xylene are selected in the model using a detailed chemical kinetic mechanism with 330 species and 1957 reactions. Included in the model are growth mechanisms of Polycyclic Aromatic Hydrocarbon (PAH), which are known to be important for soot formation. Studies are performed to describe the fundamental combustion characteristics of

Cung, Khanh D., Johnson, Jaclyn E., Zhang, Anqi, Naber, Jeffrey D., Lee, Seong-Young

Analysis Comparison between CFD and FEA of an Idealized Concept V- Hull Floor Configuration in Two Dimensions

2024-01-3222

11/15/2024

Abstract: An idealized concept of a v-hull vehicle design for blast analysis has been studied in two different commercial software packages and results are compared to one another. The two software packages are different in nature: one code is an Eulerian Computational Fluid Dynamics (CFD) Finite Volume Solver while the other code is a Lagrangian Finite Element Analysis (FEA) Solver with the ability to couple structures to fluids through a special technique called Arbitrary Lagrangian Eulerian (ALE). The simulation models in this paper have been set up for both CFD and FEA using a commercial pre-processing tool to study the effect of an idealized blast on the vehicle configuration: A pressure blast charge has been placed under the center of the vehicle at the symmetry line. The charge is composed of a prescribed pressure and a temperature pulse in a medium with the properties of air. In the CFD solver, an explicit unsteady solver has been chosen for analysis purposes. This was done

Khatib-Shahidi, Bijan, Smith, Rob E.

ADAPTATION OF THE DYNAMIC MODE DECOMPOSITION METHODOLOGY TO HIGH REYNOLDS NUMBER FLOW OVER A GROUND VEHICLE : CHALLENGES AND MITIGATION

2024-01-4024

11/15/2024

ABSTRACT The Dynamic Mode Decomposition (DMD) has shown the ability to extract coherent structures and dominant modes from high dimensional, sequential flow field datasets by decomposing it into spatial patterns and associated time dynamics. This low-rank dataset can then be applied to a linear regression model to predict the future state of the flow. Additionally, the DMD with control (DMDc) algorithm enables the input of control signals to the system, a very promising avenue for developing active aero devices for ground and aerial vehicles. However, existing literature primarily consists of its applications to low Reynolds number flows past simple, and mostly two-dimensional geometries. Given that most flows of engineering interest involve three-dimensional turbulent flows having high Reynolds number, this paper explores and presents DMD analyses of the flow around an idealized ground vehicle (Ahmed body) at a Reynolds number of 2.7 million. The high dimensional dataset for this

Misar, Adit, Nichols, Spencer, Korivi, Vamshi M., Tison, Nathan A., Uddin, Mesbah

THE CHALLENGES OF COMPARING PROPULSION COOLING CFD STUDIES TO TEST CHAMBER AND ON-ROAD PERFORMANCE

2024-01-3272

11/15/2024

ABSTRACT The thermal test chambers available at TARDEC for validation and development testing are different in terms of capability, size, and flow setup. The effects of the chamber setup on propulsion cooling airflow and the challenges of using thermal chamber tests to correlate CFD results and predict off-road performance will be discussed. Numerical simulation and test results for both a tracked combat vehicle tested in a large test cell and a wheeled MRAP vehicle tested in a smaller test cell will be presented. Numerical simulation results for these two different vehicles in on-road type of scenario and test chamber scenario at full-load cooling will be compared and contrasted. Results from CFD simulation with test cell set-up will be compared with actual physical testing in the test chamber. Procedures used for the propulsion cooling CFD simulation, best practices, limitations, and recommended procedure will be presented in detail

Shurin, Scott, Korivi, Vamshi M.

DEVELOPMENT OF A VALIDATED THERMAL MODEL OF AC PERFORMANCE IN A PROTECTED COMBAT GROUND VEHICLE

2024-01-3118

11/15/2024

ABSTRACT A coupled thermal and computational fluid dynamics (CFD) full-vehicle model of a protected combat ground vehicle was developed and validated against measured test data. The measurement dataset was collected under thermally extreme conditions. Air temperatures were sampled inside the crew compartment of the vehicle under tactical idle operating conditions with space heaters substituted for on-board electronics. The results generated from the coupled thermal model correlated with the measured test data with an average absolute error of less than 2 °F for both simulated-electronics on and off conditions. The model was used to analyze thermal sensitivity to armor, insulation, and other factors affecting the efficiency of the HVAC system

Pryor, Josh, Ditty, Aaron, Mao, Julia, Rynes, Pete, Smith, Rob

Fire Suppression Modeling using Computational Fluid Dynamics

2024-01-3492

11/15/2024

ABSTRACT Military ground vehicles are equipped with Automatic Fire Extinguishing Systems (AFES) to protect against enemy threats causing fuel tank ruptures and resulting fuel fires inside military vehicle crew compartments. The fires must be rapidly extinguished without reflash to ensure Soldier protection from burn and toxicity risks. This summary describes the development of a simulation-based acquisition tool which will complement vehicle testing for the optimization of AFES designs for specific vehicles and address their unique clutter characteristics. The simulation-based acquisition tool using Computational Fluid Dynamics (CFD) techniques was validated for an exploratory test box and demonstrated with the evaluation of two different suppressant nozzle configurations for an MRAP vehicle. The result is a cost-savings tool with a negligible development payback period that optimizes Soldier survivability in a fire situation. This modeling tool is currently being applied to predict

Korivi, Vamshi M., Williams, Bradley A., McCormick, Steven J., Deshmukh, Kshitij

Research on Drag Reduction Matching of Modular Flying Cars Based on Nested Configuration

2024-01-7016

11/15/2024

This paper investigates the drag reduction matching of modular flying cars based on a nested configuration. To address the high aerodynamic drag issue of traditional modular flying car configurations, a nested design scheme is proposed. In this scheme, the cabin is extracted from a low-drag car and combined with the flying module using a nested approach, achieving aerodynamic matching between the cabin, driving module, and flying module. First, the conceptual design of the new modular flying car and the parameters of each module, including the driving module, cabin module, and flying module, are introduced. Then, computational fluid dynamics (CFD) methods are utilized to numerically simulate the aerodynamic characteristics of the new flying car, and the results are compared with the existing typical modular flying car, AIRBUS. The research results show that the nested modular flying car exhibits superior aerodynamic performance in both driving and flying modes. Compared to the typical

Li, Yanlong, Ye, Shengfei, Zhou, Hua

eVTOL Flys Through Atmospheric Boundary Layer: Unsteady Take-Off and Landing Study via Spatio-Temporal Projection Method

2024-01-7014

11/15/2024

An electric vertical take-off and landing aircraft (eVTOL) is a variety of vertical take-off aircraft driven by electric power. This work proposed a new boundary condition control method to investigate the take-off and landing process of eVTOL, which is under the conditions of a typical atmospheric boundary layer. The spatial flow field information, especially the height-dependent atmospheric crosswind velocity profile, will be projected on the temporal axis and superimposed with the existing time-dependent unsteady conditions. Taking a 4-axis eVTOL as an example, computational fluid dynamics (CFD) simulations based on unsteady Reynolds-Averaged Navier-Stokes (uRANS) and rigid body motion (RBM) are carried out with proposed unsteady boundary conditions. The loads and surrounding flow field of the aircraft are obtained, while the vortical structures are further identified and discussed. Notably, the impact of atmospheric boundary layer on the aerodynamic force of eVTOL during vertical

Wei, Huanxia, Jia, Chundong, Shi, Yongwei, Jia, Qing, Xia, Chao, Mo, Reng, Yang, Zhigang, Li, Yanlong, Hu, Qiangqiang

Design and Analysis of Bipolar Plates in Proton Exchange Membrane Fuel Cells Using Computational Fluid Dynamics Analysis

2024-01-4324

11/05/2024

Inadequately designed flow field layouts in bipolar plates within Proton Exchange Membrane fuel cells (PEMFCs) may lead to ineffective water removal and impede reactant transport. This work examines the conventional flow channel designs like that parallel, pinhole, spiral, maze, leaf-like, modified serpentine with two bypass channels, and modified serpentine with four bypass channels in bipolar plates of fuel cells and implements modifications to certain designs to alleviate pressure drops within the flow channels using computational fluid dynamics (CFD) analysis. These designs are optimized by changing different parameters such as size of the channel and rib width utilizing Taguchi L27 standard orthogonal array. The resultant reduction in pressure drop is anticipated to enhance the overall performance of the fuel cell. The optimal flow field design of bipolar plates (Graphite and Aluminum) are manufactured using CNC milling. Tests evaluating surface roughness, contact angle, and

C, Balamurugan, S, Jeno, C, Adhikesavan, A, Praveen

Numerical Evaluation of Fuel-Air Mixing in a Direct-Injection Hydrogen Engine Using a Multi-Hole Injector

2024-01-4295

11/05/2024

Hydrogen as a chemical energy carrier is considered as one of the most promising options to achieve effective decarbonization of the transportation sector, due to its carbon-free chemical composition. This is particularly true for applications that rely on internal combustion engines (ICEs), although much research is still needed to achieve stable, reliable, and safe operations of the engine. To this purpose, direct injection (DI) of gaseous hydrogen during the compression stroke offers great potential to avoid backfire and largely reduce preignition issues, as opposed to port-fuel injection. Recently, much research has been dedicated, both experimentally and numerically, to understanding the physics and chemistry connected with hydrogen’s mixing and combustion processes in ICEs. This work presents a computational fluid dynamics (CFD) study of the hydrogen DI process in an optical engine operating at relatively low tumble conditions. Gaseous hydrogen pressurized at 86 bar is introduced

Torelli, Roberto, Wu, Bifen, Park, Ji-Woong, Pei, Yuanjiang

Multidisciplinary and Integrated Approach to Predict Automotive Axle System Efficiency

2024-01-4314

11/05/2024

In today’s competitive automotive market, customers are now looking for system efficiency as one of the important design parameters of system performance along with durability and reliability. It is essential to ensure products are designed to utilize maximum input power and have better system efficiency. In automotives, transmission and axle systems are power transmitting elements from prime mover to wheels and are one of the main contributors to overall vehicle efficiency. Hence, predicting and assessing overall system efficiency of these aggregates is of paramount importance. System efficiency is driven by component power losses for various speeds and torques, which are arising out of component design parameters, complex interaction within system, operating conditions, lubrication, temperatures etc. To capture multi-physics of speed and torque dependent losses of automotive axle, multidisciplinary and integrated approach is proposed in this paper, Efficiency predictive model is

Dambir, Gaurav

Numerical Investigation of the Combustion Process and Emissions Formation in a Heavy-Duty Diesel Engine Featured with Multi-Pulse Fuel Injection

2024-01-4285

11/05/2024

Combustion in conventional and advanced diesel engines is an intricate process that encompasses interaction among fuel injection, fuel-air mixing, combustion, heat transfer, and engine geometry. Manipulation of fuel injection strategies has been recognized as a promising approach for optimizing diesel engine combustion. Although numerous studies have investigated this topic, the underlying physics behind flame interactions from multiple fuel injections, spray-flame-wall interaction and their effects on reaction zones, and NOx/soot emissions are still not well understood. To this end, a computational fluid dynamics (CFD) study is performed to investigate the effects of pilot and post injections on in-cylinder combustion process and emissions (NOx and soot) formation in a heavy-duty (HD) diesel engine. A full-sector CFD model of the HD engine employing detailed chemistry is validated against experimental data for in-cylinder pressure, heat release rate, combustion phasing, and engine-out

Singh, Harsimran, Kutkut, Almoutazbellah, Pal, Pinaki, Aggarwal, Suresh Kumar, Li, Hailin

Prediction of Water Film Thickness Due to Condensation over Instrument Cluster Based on Eulerian Wall Film Approach of Computational Fluid Dynamics

2024-28-0009

10/17/2024

This paper investigates the condensation within a two-wheeler instrument cluster in different weather conditions. Instrument cluster have high heating components within its assembly particularly over Printed Circuit Board (PCB) which leads to formation of condensation. Air breathers are important component that can be utilized to reduce the condensation in the cluster. Location and orientation of air breather and air vents plays the vital role in the air flow through the instrument cluster. In this study, number of breathers, their location and orientation are optimized to reduce the condensation or film thickness on the crystal (transparent body) of cluster. Transient Computational Fluid Dynamics (CFD) based Eulerian Wall Film approach is utilized to investigate the physics administering the condensation phenomenon in the instrument cluster. Experimental tests are conducted to investigate condensation phenomenon actually occurring in the model. Similar results are found by employing

Jamge, Nagesh, Shah, Viren, Kushari, Subrata, Miraje, Jitendra, D, Suresh

AIML Enabled Rapid Vehicle Aerodynamics Design Improvements

2024-28-0007

10/17/2024

The integration of Artificial Intelligence (AI) and Machine Learning (ML) technologies has significantly changed various industries. This study demonstrates the application of a Convolutional Neural Network (CNN) model in Computational Fluid Dynamics (CFD) to predict the drag coefficient of a complete vehicle profile. We have developed a design advisor that uses a custom 3D CNN with a U-net architecture in the DEP MeshWorks environment to predict drag coefficients (Cd) based on car shapes. This model understands the relationship between car shapes and air drag coefficients calculated using computational fluid dynamics (CFD). The AI/ML-based design advisor feature has the potential to significantly decrease the time required for predicting drag coefficients by conducting CFD calculations. During the initial development phase, it will serve as an efficient tool for analyzing the correlation between multiple design proposals and aerodynamic drag forces within a short time frame

Bijjala, Sridhar

Design Optimization of Air Duct for Noise Reduction Using Gaussian Process Regression Algorithm

2024-28-0042

10/17/2024

In the context of Battery Electric Vehicles (BEVs), airborne noise from Heating, Ventilation and Air Conditioning (HVAC) ducts becomes a prominent concern in the view of passenger comfort. The automotive industry traditionally leverages Computational Fluid Dynamic (CFD) simulation to refine HVAC duct design and physical testing to validate acoustic performance. Optimization of the duct geometry using CFD simulation is a time-consuming process as various design configurations of the duct have to be studied for best acoustic performance. To address this issue effectively, the proposed a novel methodology uses Gaussian Process Regression (GPR) to minimize duct noise. Present solution demonstrates the power of machine learning (ML) algorithms in selecting the optimal duct configuration to minimize noise. Utilizing both real test data and CFD results, GPR achieves remarkable accuracy in design validation, especially for HVAC air ducts. The adoption of GPR-based ML algorithms significantly

Althi, Tirupathi Rao, Manuel, Naveen, K, Manu

Numerical and Experimental Investigation of Water Cooled Reciprocating Air Compressor Used in Automotive Applications

2024-28-0014

10/17/2024

Most of the heavy commercial vehicles are installed with Pneumatic brake system where the medium is a pressurized pneumatic air generated with the reciprocating air compressor. Heating is an undesirable effect of the compression process during loading cycles as reciprocating air compressors are concerned. Therefore it is necessary to reduce the delivery air temperature of compressor for safer operation of downstream products. The present investigation deals with the measurement of the delivery air temperature of a typical 318 cc water cooled compressor. A through steady state conjugate heat transfer analysis is conducted for the given speed and with the specification cooling water flow rate to predict the delivery air temperature. Pressure drop across the cooling water flow path has been measured and optimum flow rate is arrived to meet the design requirement. The results of characteristic analysis and comparative research show that the cooling system can obviously reduce the cylinder

N, Prabhakar, V A, Sahaya Irudayaraj, Raj, Amal, T, Sukumar

Design Optimization of Heat Transfer in Automotive Battery Using Generalized Neural Network Regression

2024-28-0024

10/17/2024

Electrification is driving the use of batteries for a range of automotive applications, including propulsion systems. Effective management of thermal energy in lithium-ion battery pack is essential for both performance and safety. In automotive applications especially, understanding and managing thermal energy becomes a critical factor. Cells in the propulsion battery pack dissipate heat at high discharge rates. Cooling performance of battery can be realized by optimizing the various parameters. Computational Fluid Dynamics (CFD) model build and simulations are resource intensive and demand high performance computing. Traditionally, evaluating thermal performance involves time-consuming CFD simulations. To address this challenge, the proposed novel approach using Generalized Neural Network Regression (GNNR) eliminates complex CFD model building and significantly reduce simulation time. GNNR achieves up to 85% accuracy in predicting Heat Transfer coefficient. The benefits of GNNR extend

Althi, Tirupathi Rao, Manuel, Naveen, K, Manu

Numerical Investigation on Performance Based Methodology for Developing Vane Design of AC Duct

2024-28-0004

10/17/2024

Airflow directionality in a vehicle cabin is one of the concerns of car owners, researchers, and vehicle manufacturers. After exposed/parked in hot ambient condition for a long time, HVAC system normally takes few minutes to cool down and reach an acceptable cabin temperature for the passenger comfort. To ensure proper airflow distribution inside the cabin, the AC duct & vanes ability to direct airflow must be evaluated. Objective of this work is to propose a methodology for developing the vane design of AC system duct using CFD approach. Two different goals are attempted. Firstly, the effect of horizontal and vertical vane angle on airflow directionality is investigated with DoE approach. Then factors influencing the airflow directionality are investigated using factorial study approach. CFD based factorial analysis (L9 orthogonal array) was conducted using three components at three levels. The impact of number of horizontal vanes, number of vertical vanes and distance between them on

Mahesh, A, Baskar, Subramaniyan, Raju, Kumar, Gopinathan, Nagarajan

Investigating Methods to Generate Models for Turbine Maps Using Machine Learning

02-17-04-0019

10/09/2024

For turbocharged engine design, manufacturer-provided turbocharger maps are typically used in simulation analysis to understand key engine performance metrics. Each data point in the turbocharger map is generated by physically testing the hardware or through CFD analysis—both of which are time-consuming and expensive. As such, only a modest set of data can be generated, and each data map must be interpolated and extrapolated to create a smooth surface, which can then be used for engine simulation analysis. In this article, five different machine learning algorithms are described and compared to experimental data for the prediction of Cummins Turbo Technologies (CTT) fixed geometry turbines within and outside of the experimental data range. The results were validated against xxx-provided test data. The results demonstrate that the Bayesian neural networks performed the best, realizing a 0.5%–1% error band. In addition, it is extrapolatable when suitable manually created extra data

Supe, Shreyas, Natarajan, Bharath, Shaver, Greg

Comprehensive Analysis of Needle Bearing Failures in Fuel Transfer Pumps: Insights from Testing and Finite Element Analysis

03-18-01-0004

10/09/2024

This study investigates the failure mechanisms of needle bearings within fuel transfer pump assemblies through a comprehensive approach combining endurance testing, detailed inspection, the Dykem blue method, proximity sensors, and finite element analysis (FEA). The findings reveal critical insights into the causes of failure, highlighting significant axial displacement, with a maximum of 0.37 mm measured by proximity sensors. The Dykem technique identified distinct wear patterns across various components, pinpointing areas of high stress and potential failure. Detailed bearing inspections uncovered trunnion damage and abrasive wear, corroborated by FEA, which quantified displacements of 0.144 mm in the x-direction, 0.030 mm in the y-direction, and 0.015 mm in the z-direction. The primary operational factors contributing to bearing failure were contamination and inadequate axial control. These insights are pivotal, as they align with and expand upon established literature on bearing

Kaliyanda, Aneesh

Variable Geometry Turbine Turbocharger Optimization Using Machine Learning for On-Highway Fuel Cell Applications

02-17-04-0020

10/07/2024

Turbocharger design involves adjustment of various geometric parameters to improve the performance and suit mechanical constraints, depending on the application-specific requirements. In designing the turbine stage, these parameters are optimized to maximize durability and efficiencies at the required operating points. For a heavy-duty class eight truck, “road load” and “rated power” are generally considered the two most important operating points. The objective of this article is to improve the efficiencies of these two operating points. The common challenge in the development of a turbine wheel design is the large number and interdependence of parameters to optimize. For example, increasing the blade thickness improves structural strength but reduces the mass flow capacity, thus influencing its performance. It is general practice to optimize the wheel geometry using iterative CFD analysis. However, running simulations for every single change in geometry involves significant

Wichlinski, Joseph, Gonser, Lukas, Naik, Pavan, Taylor, Alexander H., Al-Hasan, Nisar S.

Cooling of Military Avionic Equipment

AIR1277B (Current)

10/03/2024

This SAE Aerospace Information Report (AIR) contains information on the thermal design requirements of airborne avionic systems used in military airborne applications. Methods are explored which are commonly used to provide thermal control of avionic systems. Both air and liquid cooled systems are discussed

AC-9 Aircraft Environmental Systems Committee

Multiscale and Multidomain Digital Twins for Vehicle Thermal Management Applications

2024-28-0114

09/19/2024

Effective thermal management is crucial for vehicles, impacting both passenger comfort and safety, as well as overall energy efficiency. Electric vehicles (EVs) are particularly sensitive to thermal considerations, as customers often experience range anxiety. Improving efficiency not only benefits customers by extending vehicle range and reducing operational costs but also provides manufacturers with a competitive edge and potential revenue growth. Additionally, efficient thermal management contributes to minimizing the environmental impact of the vehicle throughout its lifespan. Digital twins have gained prominence across various industries due to their ability to accelerate development while minimizing testing costs. Some applications have transitioned to comprehensive three-dimensional models, while others employ model reduction techniques or hybrid approaches that combine different modeling methods. The discovery of unknown working mechanisms, more efficient and effective control

Palacio Torralba, Javier, Kapoor, Sangeet, Jaybhay, Sambhaji, Locks, Olaf, Kulkarni, Shridhar Diliprao, Shah, Geet

Electro-Thermal Analysis of Permanent Magnet Synchronous Motor for Electric Vehicles

2024-28-0080

09/19/2024

Permanent magnet synchronous (PMS) motors are frequently used in electric vehicles because of their high power density, stable output torque and low noise. During the operation of an electric motor, some of the electrical energy is converted into heat. The rise in motor temperature hampers motor performance (power output, demagnetization, breakdown of winding insulation, efficiency and component lifespan). The losses occurring in electric motors during operation mainly include: stator loss, winding copper loss, rotor iron loss, eddy current loss in magnets and mechanical losses. The life and operating reliability of a motor depends on the thermal performance of the motor. This paper describes a detailed procedure for an indirect coupled analysis between Ansys Maxwell and Ansys Fluent, in order to predict critical thermal characteristics of the motor and cooling jacket. The main objective of this paper is to model the PMS motor with a cooling system based on input electrical and

Shandilya, Anand, Kumar, Vivek

Items per page:

1 – 50 of 4382