Browse Topic: Pressure

Items (9,165)

In Situ Observation of Different Soot Layers in a Model Filter Channel During Its Regeneration

2025-01-0312To be published on 07/02/2025

To keep the air clean, wall-flow particulate filters are predominantly used in the exhaust gas after-treatment systems of combustion engines to remove reactive soot and inert ash particles. These filters consist of parallel porous channels with alternately closed ends, effectively separating particles by forming a layer on the filter surface. However, the particulate layer increases the pressure drop, requiring periodic regeneration. During regeneration, soot oxidation breaks up the particulate layer, while resuspension and transport of individual agglomerates may occur. These phenomena are influenced by gas temperature and velocity, as well as dispersity and the reactivity of the soot particles. Sustainable fuels can produce different types of soot with different reactivities and dispersities, therefore this study focuses on the influences of soot dispersity and reactivity by varying the reactive particle system. A model wall-flow filter channel is used for the investigation, enabling

Desens, Ole, Hagen, Fabian P., Meyer, Jörg, Dittler, Achim

Development of Simple Models for Performance Estimation of a Spark Ignition Engine Fueled with Ammonia and Hydrogen

2025-01-0238To be published on 06/16/2025

Achieving a carbon neutral society, eliminating greenhouse gas emissions is one of the most important issues. Ammonia is expected as a carbon free energy source. However, the laminar burning velocity of ammonia is much slower than hydrocarbons. Then, it is common to reform a portion of ammonia and use the ammonia/hydrogen mixture as a fuel. In this research, the operating characteristics of spark-ignition engine fueled with ammonia reformed gas is investigated and construct model estimating engine performance. A four-stroke single cylinder spark-ignition engine with a stroke volume of 212 cm3 is used. Total equivalence ratio is kept at unity and ammonia equivalence ratio is changed. Also, ammonia reformed gas is simulated as follows: ammonia and hydrogen are supplied from high pressure cylinders and injected by using automobile gaseous fuel injectors. Nitrogen is supplied from high pressure cylinder and supplied 1/3 of the molar ratio to hydrogen by a mass flow controller. The test

Ichikawa, Aya, Ogura, Yuto, Yanaoka, Kazuki, Gonzalez Palencia, Juan, Kambara, Shinji, Araki, Mikiya

numerical investigation into the combustion and emission characteristics of ammonia direct injection mechanism

2025-01-0241To be published on 06/16/2025

Ammonia is an attractive option because of its relatively low greenhouse gas (GHG) emissions, high energy density, competitive cost, and ubiquitous infrastructure for manufacturing, storage, and distribution. In this work, the optimum combustion characteristics are investigated to propose an efficient ammonia engine for future investigation. The effects of ammonia addition on diesel combustion characteristics were numerically investigated in a CI engine. The investigation was conducted by structured 3D CFD modeling to analyze the combustion characteristics. The validation of the boundary condition was compared to the designed experimental ammonia engine. The direct injection timing of 10o-50oBTDC and injection pressure 300-800 bar was proposed to identify the optimum autoignition characteristics. The equivalence ratios 1, 0.75, 0.5, and 0.25 were used in order to analyze the high cetane number characteristics and the air-fuel ratio.

Setiawan, Ardhika, Lim, Ocktaeck

Development of an Intelligent Instrumented Tire for Real-Time Hydroplaning Risk Estimation

10-09-03-0027

05/21/2025

This study introduces an innovative intelligent tire system capable of estimating the risk of total hydroplaning based on water pressure measurements within the tread grooves. Dynamic hydroplaning represents an important safety concern influenced by water depth, tread design, and vehicle longitudinal speed. Existing intelligent tire systems primarily assess hydroplaning risk using the water wedge effect, which occurs predominantly in deep water conditions. However, in shallow water, which is far more prevalent in real-world scenarios, the water wedge effect is absent at higher longitudinal speeds, which could make existing systems unable to reliably assess the total hydroplaning risk. Groove flow represents a key factor in hydroplaning dynamics, and it is governed by two mechanisms: water interception rate and water wedge pressure. In both the shallow water and deep water cases, the groove water flow will increase as a result of increasing the longitudinal speed of the vehicle for a

Vilsan, Alexandru, Sandu, Corina, Anghelache, Gabriel, Warfford, Jeffrey

Experimental Investigation of Carbon Nanotube Additives Effect on Performance and Emission of a High-Injection Pressure Common Rail Diesel Engine

03-18-03-0020

05/16/2025

Due to the continuous decrease in fossil fuel resources, and drawbacks of some biofuel properties, in addition to restricted environmental concerns, it becomes a vital manner to innovate some approaches for energy saving and emission reduction. One of the promising approaches is to enhance the fuel properties via adding nanoparticles. Carbon nanotubes (CNTs) blended with biofuels get extensive investigations by researchers using conventional diesel engines at relatively limited operating regimes. The objective of this work is to extend these studies using diesel fuel, rather than biofuels, on a high-injection pressure (1400–1600 bar) common rail diesel engine at wide operating conditions and higher CNT concentrations. Experimental results show an increase in peak pressure up to 24.46% than pure diesel when using 100 ppm CNTs concentration. Also, BSFC has decreased by 33.19%, and BTE increased by 54.2% compared to pure diesel fuel at high speeds and loads. NOx and CO2 emissions raised

Moaayet, Sayed, Neseem, Waleed Mohamed, Amin, Mohamed Ibrahim, Shahin, Motasem Abdelbaky

Study on the Aspiration Properties of Glassrun Seal System under Time-Varying Pressure Difference

2025-01-0030

05/05/2025

When a vehicle is driven at high speed, there exists intricate flow pattern and vortex shedding at the side window area with intense pressure fluctuation. A significant dynamic pressure difference between the vehicle's exterior and interior can render the side window sealing system vulnerable to aspiration. This susceptibility can lead to the generation of leakage noise, adversely affecting acoustic comfort in the vehicle's cabin. This paper delves into the aspiration properties of glassrun seal system under time-varying pressure difference. A nonlinear finite element model of the glassrun seal was established to simulate the quasi-static deformation of the sealing strip during installation process, which aims to obtain the deformed geometric shape and residual stress after this process. Then, the exterior flow field of the glassrun sealing area of a simplified vehicle model was calculated with CFD simulation to obtain the hydrodynamic pressure excitation acting on the outer surface of

Li, Hanqi, He, Yinzhi, Zhang, Lijun, Zhang, Yongfeng, Yu, Wuzhou, Jiang, Zaixiu, Blumrich, Reinhard, Wiedemann, Jochen

Comprehensive Analysis and Optimization of Door Closing Sound Quality of a Heavy Truck

2025-01-0066

05/05/2025

Based on the objective and subjective experiment and finite element analysis, the influencing factors on the door closing sound quality of a heavy truck is analyzed and optimized. Results show that the loudness and sharpness can be reduced by increasing stiffness and damping of the door. The sound quality can be enhanced by increasing the pressure release area, which can decrease the air pressure resistance of dooring closing. By adding holes on the inner liner and changing the pressure release location, the dooring closing air pressure resistance is reduced from 289 Pa to 181 Pa. In terms of the rebound sound, the sound level is positively related to the door closing force. Increasing the protrusion height and decreasing the stiffness of the vibration absorber of the handle can improve the rebound sound quality. Optimizing the absorbers on both ends of the handle and adding damping material can decrease the loudness by 47.8%, reduce the cavity sound, reduce the rattle and improve the

Wang, Jian, Zhang, Yongshen, Feng, Lei, Xie, Chenhao, Lin, Jiewei, Sun, Changchun

Characterize the Sound Field Generated from a Vehicle Horn by Pellicular Analysis

2025-01-0058

05/05/2025

To predict the sound field produced by a vehicle horn requires a good source representation of it in the full vehicle model. This paper investigates the characterization of a physical vehicle horn by an inverse method called pellicular analysis. To implement this method, firstly an acoustic testing is performed to measure the sound pressure radiated from the horn at a certain number of microphone locations in a free field environment. Based on the geometry of a virtual horn, the locations of each microphone and measured sound pressure data, pellicular analysis is adopted to recover a set of vibration pattern of the virtual horn. The virtual horn and the recovered vibration information are then incorporated in a full vehicle numerical model to simulate its exterior sound field. The validity of this approach is confirmed by comparing the prediction for a horn in a production vehicle to the corresponding physical test which is required to meet the Brazilian regulation CONTRAN 764/2018.

Yang, Wenlong, Melo, Andre

Experimental Investigation into Modulated Aeroacoustic Cabin Noise Arising from Unsteady Flow Conditions

2025-01-0029

05/05/2025

The unsteady wind conditions experienced by a vehicle whilst driving on the road are different to those typically experienced in the steady-flow wind tunnel development environment, due to turbulence in the natural wind, moving through the unsteady wakes of other road vehicles and travelling through the stationary wakes generated by roadside obstacles. This paper presents an experimental approach using a large SUV-shaped vehicle to assess the effect of unsteady wind on the modulated noise performance, commonly used to evaluate unsteady wind noise characteristics. The contribution from different geometric modifications were also assessed. The approach is extended to assess the pressure distribution on the front side glass of the vehicle, caused by the aerodynamic interactions of the turbulent inflow in straight and yawed positions, to provide insight into the noise generation mechanisms and differences in behaviour between the two environments. The vehicle response to unsteady wind

Jamaluddin, Nur Syafiqah, Oettle, Nicholas, Staron, Domenic

Tonal Noise Investigation of Automotive HVAC Systems: A Hybrid Method

2025-01-0027

05/05/2025

There is no need to recall how the electrification trend of transport facilities has tightened the requirements around acoustic comfort. Within the automotive industry, these targets are more challenging for Heating, Ventilation and Air Conditioning systems for which passengers are in the frontline of noise emissions inside the car cabin. The complexity of the requirements and specifications set by car manufacturers and suppliers stems from a dual aspect. First is quantitative based on the sound pressure level, whether it's the overall level or 1/3 octave band spectra. The second is purely subjective, based on the perceived noise quality by stakeholders and final customers worldwide. During development phases, low tonal noises are frequently encountered on these systems which might induce discomfort to the passengers. The experimental investigations usually point to an aerodynamic origin, which prompted this research activity. The purpose of this work is to analyze and understand the

Bennouna, Saad, Alaoui, Mohamed, Henner, Manuel

GPU-Accelerated Aeroacoustic Simulations of HVAC Duct Configurations

2025-01-0133

05/05/2025

Large eddy simulations (LES) of two HVAC duct configurations at different vent blade angles are performed with the GPU-accelerated low-Mach (Helmholtz) solver for comparison with aeroacoustics measurements conducted at Toyota Motor Europe facilities. The sound pressure level (SPL) at four near-field experimental microphones are predicted both directly in the simulation by recording the LES pressure time history at the microphone locations, and through the use of a frequency-domain Ffowcs Williams-Hawking (FW-H) formulation. The A-weighted 1/3 octave band delta SPL between the two vent blades angle configurations is also computed and compared to experimental data. Overall, the simulations capture the experimental trend of increased radiated noise with the rotated vent blades, and both LES and FW-H spectra show good agreement with the measurements over most of the frequency range of interest, up to 5,000Hz. For the present O(30) million cell mesh and relatively long noise data collection

Besem-Cordova, Fanny M., Dieu, Donavan, Wang, Kan, Brès, Guillaume A., Delacroix, Antoine

Assignment Criteria for Function Allocation to Commercial Aviation System Security Domains

2025-01-0156

05/02/2025

Aircraft cabin management is characterized by operational and business processes. Both are defined as a logical sequence of activities that occur during the flight. While the operational process includes activities to ensure flight safety, such as take-off, cruise and landing, the business process activities are related to adding value to the customer, i.e. the passenger. They are to be certified by the authority as a part of the aircraft type certification. These processes are defined by the airline and are described as part of the airline’s business model. While the scope of operational processes for passenger safety within the aircraft cabin should remain as unchanged as possible, the increasing competitive pressure on airlines is leading to a constantly rising number of services in the cabin. To prevent compromising cabin safety from increased cabin crew workload during the cruise phase, there is a growing trend toward digitizing operational and business processes. The digitized

Hintze, Hartmut, Blecken, Marvin, God, Ralf, Pereira, Daniel

Numerical Studies on the Relation between the Multiple Auto-Ignition and Pressure Wave in the Premixed Charge

2024-32-0079

04/18/2025

The relation between the multiple auto-ignition in the premixed charge with fuel concentration distribution and associated pressure wave are 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 elementary chemical reactions of the compressible reacting fluid flow described in the one-dimensional coordinate system with high spatial and time resolution was performed to clarify the detailed phenomena of the onset of the multiple auto-ignition and the pressure wave propagation in the gas.

Iizumi, Kota, Yoshida, Kenji

Detailed Approach for Pre-Chamber Heat Release Analysis for the HSASI Pre-Chamber Spark Plug Using a Pressure Sensor Glow Plug

2024-32-0063

04/18/2025

The hot surface-assisted spark ignition (HSASI) pre-chamber spark plug, which was developed at the Karlsruhe University of Applied Sciences, increases the dilution limit with excess air and the tolerance to residual gas in the pre-chamber compared to a conventional passive pre-chamber spark plug. In this study, the conventional glow plug which is integrated in the pre-chamber of the HSASI pre-chamber spark plug was replaced by a pressure sensor glow plug (PSG) from BERU. This allows for a detailed combustion analysis in the pre-chamber. The signal of the PSG was validated with a piezoelectric cylinder pressure sensor and a method to analyse the pre-chamber heat release was introduced. Experimental investigations were carried out on a single-cylinder gasoline engine. A series of operating points diluted with excess air and a variation in load were conducted. The gas flow rate through the orifices of the pre-chamber was calculated from the pressure difference between the pre-chamber and

Holzberger, Sascha, Kettner, Maurice, Kirchberger, Roland

Study on the Optimal Pre-Chamber Geometry for Active Pre-Chamber Gas Engines

2024-32-0023

04/18/2025

In a pre-chamber engine, fuel in the main-chamber is ignited and combusted by the combustion gas injected from the pre-chamber. Therefore, further fuel dilution is possible and thermal efficiency can be also improved. However, adding a pre-chamber to an engine increases the number of design parameters which have a significant impact on the main combustion and the exhaust gas. Then, in this study, the optimum geometry of the pre-chamber in an active pre-chamber gas engine was investigated. The considered parameters were the volume of pre-chamber, the diameter of a nozzle hole, and the number of nozzle holes. 18 types of pre-chambers with different geometries were prepared. Using these pre-chambers, engine experiments under steady conditions were conducted while changing the conditions such as engine speeds, mean indicated pressure and air excess ratio. Based on the experimental data, neural network models were constructed that predict thermal efficiency, NOx and CO emissions from the

Yasuda, Kotaro, Yamasaki, Yudai, Sako, Takahiro, Takashima, Yoshitane, Suzuki, Kenta

Effects of Hydrogen Addition on Spark Knock Suppression under High Engine Speed and Boosted Conditions

2024-32-0108

04/18/2025

The effect of hydrogen addition on spark knock suppression under high engine speed (4800 rpm) was investigated at the intake pressures of 96 kPa and 120 kPa. The experimental results showed that hydrogen addition has a slight effect on advancing the knock limit at 96 kPa, whereas a greater spark knock suppression effect can be achieved by increasing the intake pressure. To elucidate the influences and differences of hydrogen addition on the ignition process under low and high intake pressures, chemical kinetic analyses were performed using a two-zone combustion model. The calculation results showed that the reduction of heat release in the end gas resulting from the consumption of OH radicals by hydrogen can only be achieved at the initial stage of the ignition process. This leads to the smaller knock suppression effect at low intake pressures, where a remarkable heat release at this stage is absent. On the other hand, an increase in intake pressure results in a remarkable heat release

Goto, Jun, Ueno, Yoshito, Kobashi, Yoshimitsu, Shibata, Gen, Ogawa, Hideyuki, Kojima, Kentaro

Experimental Study on Thermo-Catalytic Ammonia Decomposition into Hydrogen

2024-32-0118

04/18/2025

In order to rapidly achieve the goal of global net-zero carbon emissions, ammonia (NH3) has been deemed as a potential alternative fuel, and reforming partial ammonia to hydrogen using engine exhaust waste heat is a promising technology which can improve the combustion performance and reduce the emission of ammonia-fueled engines. However, so far, comprehensive research on the correlation between the reforming characteristic for accessible engineering applications of ammonia catalytic decomposition is not abundant. Moreover, relevant experimental studies are far from sufficient. In this paper, we conducted the experiments of catalytic decomposition of ammonia into hydrogen based on a fixed-bed reactor with Ru-Al2O3 catalysts to study the effects of reaction temperature, gas hour space velocity (GHSV) and reaction pressure on the decomposition characteristics. At the same time, energy flow analysis was carried out to explore the effects of various reaction conditions on system

Li, Ze, Li, Tie, Chen, Run, Li, Shiyan, Zhou, Xinyi, Wang, Ning

Experimental Investigation of n-C7H16/Ethanol Blended Fuels on Auto-ignition and Flame Propagation in High Temperature/Pressure Constant-Volume Combustion Vessel

2024-32-0050

04/18/2025

This study aims to investigate the effect of ethanol blends on flame propagation and auto-ignition under high pressure and high temperature conditions. Experimental investigations are conducted using n-C7H16 / ethanol blends at various blending ratios (0, 5, 10, 20, 40, 70, and 100 vol%). The blends are premixed with air at stoichiometric ratios and ignited centrally in a cylindrical constant-volume combustion chamber (20-mm inner diameter, 80-mm long) under elevated temperature (500 K) and pressure (1.0 MPa) conditions. The results show that auto-ignition occurs at an ethanol blend ratio of 10% or less and ceases above 20%. Increasing the ethanol blend to 70% results in a slight change in flame propagation speed, with a noticeable delay at 100%. The pressure measurements show a peak of about 5.6 MPa at a blend ratio of 5%, which gradually decreases with increasing ratios. High-pass filtering reveals the maximum pressure fluctuation amplitude at the 5% blend ratio, indicating increased

Tateishi, Tokua, Yamaguchi, Riki, Shimokuri, Daisuke, Terashima, Hiroshi, Hara, Takaya, Honda, Yuya, Kawano, Michiharu

Aerospace Fluid Systems and Components – Pressure and Temperature Classifications

AS2001B (Current)

04/14/2025

This document establishes the temperature types and pressure classes that are commonly used in aerospace fluid systems. The temperature types and pressure classes are equivalent, but not identical, to the SI units defined in MA2001 (ISO 6771). For exact conversion use NAS 10000.

G-3, Aerospace Couplings, Fittings, Hose, Tubing Assemblies

Custom Rupture Disk Prototypes for Medical Devices

TBMG-52858

04/01/2025

Medical equipment designers rely on rupture disk devices for pressure relief and pressure release of gases and liquids for essential diagnostic, life safety, and analytical instrumentation. However, the challenge of time faces medical device OEM product designers; how do we get a custom solution in an acceptable timeframe?

Effects of Ambient and Injection Conditions on a High-Pressure Hydrogen Jet for Direct Injection in ICE

2025-01-8466

04/01/2025

The transport sector is responsible for about one third of the global CO2 emissions. To align to the net zero emission scenario, the transportation sector needs the implementation of policies aimed to reduce as much as possible the highly emitting transport options and, at the same time, the use of new technologies to reduce the environmental impact of transport methods whose emissions cannot be entirely eliminated. An exploitable solution for the internal combustion engine (ICE), even in the nearest future, would be to use hydrogen as a fuel in these engines. This is supported by the fact that H2-ICE is the only ICE technology currently capable of meeting the standards imposed by the European Union for 2035. Due to the possibility of different injection strategies as well as the variation of in-cylinder back pressure, the comprehensive knowledge of hydrogen injection jet behavior and characteristics is fundamental for improving the combustion process in direct injection H2-ICE. In

Montanaro, Alessandro, Mancaruso, Ezio, Meccariello, Giovanni, Allocca, Luigi

A Study on Cetane on Demand Technology Part 1 - Development of Fuel Reformer to Improve Fuel Ignitability

2025-01-8447

04/01/2025

The integration of low-octane gasoline with a compression ignition combustion system has been proposed as a strategy to reduce Well-to-Wheel CO2 emissions from automobiles using petroleum-based fuel. In the current situation where low-octane gasoline is not widely available in the market, onboard reforming of commercial gasoline to increase the cetane number (lower the octane number) allows for compression ignition combustion even with commercial gasoline. This requires “Cetane on Demand” technology, which enables compression ignition combustion with both commercial gasoline and low-octane gasoline. It is known that the ignition property of fuel is enhanced when the fuel is oxidized to generate hydroperoxides. Moreover, the use of N-hydroxyphthalimide (NHPI) as a catalyst promotes hydroperoxide generation at low temperatures. The objective of this study is to develop a device that enhances the ignition properties of gasoline through onboard fuel reforming. Initially, from the seven

Hashimoto, Kohtaro, Yamada, Yoshikazu, Matsuura, Katsuya, Kudo, Tomohide, Chishima, Hiroshi, Al-Taher, Maryam, Kalamaras, Christos, Albashrawi, Reem

The Numerical Study of Methane Flame Characteristics in the Ammonia/Air Environment at Sub-Atmospheric Pressure

2025-01-8450

04/01/2025

The low emission of carbon and minimum level of soot formation in combustion engines and turbines strategy is adopted by many countries to counteract global warming and climate change. The use of ammonia with hydrocarbon fuels can limit the formation of soot and carbon emissions due to non-carbon atoms. The current study explores the use of ammonia with air at coflow flame conditions, which was not tested before. It may give the choice for diesel cycle engines to use the ammonia either with air or fuel. The combustion and emission characteristics of methane coflow flame were studied at low pressure and air polluted by ammonia conditions. The results showed that a significant decline in carbon formation was observed when ammonia was boosted, 5-10%. The impact of sub-atmospheric pressure, 90-70 KPa, on COx development was higher than that of NH3 addition, 0-5%, thanks to the lower formation of hydroxymethylium, formaldehyde, and aldehyde radical. In the environment of lower pressure, the

Hina, Anam, Akram, M Zuhaib, Shafa, Amna, Akram, M Waqar

A Study on the Influence of Compression Pads on the Safety and Life of a Lithium-ion Cell Module

2025-01-8132

04/01/2025

The demand for eco-friendly electric powertrains has increased significantly in recent years. Cells are the most crucial component of a battery pack, directly influencing the dimensions, range, lifespan, performance, and cost of electric vehicles. Lithium-ion cells outperform other cell chemistries due to their higher energy density, allowing for more compact and lightweight designs while providing longer operational ranges. It is crucial that lithium-ion cell packaging complies with assembly requirements to maximize its lifespan and ensure operational safety. Assembly force requirements of lithium-ion cells are critical to ensure optimal cell performance throughout its lifetime & enhance the longevity of the battery pack. The compression pad between cells ensures appropriate cell assembly pressure. The service life is how long a lithium-ion cell can operate effectively, while the cyclic life refers to the number of charge-discharge cycles before cell functional degradation. The cell

Varambally, Vishakha, Sithick basha, Abubakker, Chalumuru, Madhu, Sasikumar, K

Effect of Catalyst Coating Strategy on NOx Reduction and Passive Soot Oxidation for Selective Catalytic Oxidation-Selective Catalytic Reduction Catalyst on Diesel Particulate Filter

2025-01-8490

04/01/2025

Selective catalytic oxidation/reduction catalysts coated on diesel particulate filters (SDPF) are an important technology route to meet next-stage emission regulations. The previous research of the research group showed that compared with SDPF coated with Cu-SSZ-13, the SDPF coated with novel selective catalytic oxidation-selective catalytic reduction (SCO-SCR) catalyst, which combined MnO2-CeO2/Al2O3 and Cu-SSZ-13, can simultaneously improve NOx reduction and soot oxidation performance. Catalyst coating strategy is an important parameter affecting the performance of SDPF. In this study, the effects of different coating strategies of SCO-SCR catalysts (C25, C50, C75, and C100) on the performance of NOx reduction and soot oxidation in SDPF were investigated. The results show that, as the inlet gas temperature increases, NO emissions first decrease and then increase, NOx conversion efficiency first increases and then decreases, and the rich-NO2 area, NH3 oxidation rate, N2O, CO, CO2

Chen, Ying-jie, Tan, Piqiang, Yao, Chaojie, Lou, Diming, Hu, Zhiyuan, Yang, Wenming

Impacts of Injection Pressure on Split-Injection Energy-Assisted Compression-Ignition Combustion of Low Cetane Number SAFs with a Gaussian-Shaped Ribbed Piston Bowl Design

2025-01-8350

04/01/2025

The impact of injection pressure on a split-injection energy-assisted compression-ignition (EACI) combustion strategy was studied in an optically accessible engine with a custom ribbed piston bowl design. Three injection pressures (600, 800, and 1000 bar) were investigated for three split-injection dwells (1.5, 2.0, and 2.5 ms) with a fixed second injection timing of -5.0 CAD. The Gaussian-shaped ribbed piston bowl design was employed to position hot combustion gases from the first injection near the centrally located injector to enable rapid ignition and mixing-controlled combustion of the second injection. At 600-bar injection pressure, as injection dwell was shortened, relocation of hot combustion gases near the injector became increasingly more difficult due to less available time for relocation and due to the higher in-cylinder densities at the start-of-injection (SOI) for the first injection. Increased injection pressure (800 and 1000 bar) improved the relocation of the first

Amezcua, Eri, Stafford, Jacob, Kim, Kenneth, Kweon, Chol-Bum, Rothamer, David

DME-to-Propane Mixture Effects on a Light Duty Compression Ignition Engine

2025-01-8415

04/01/2025

Fuels that can be produced in a sustainable manner are of high interest because they can provide an essential step toward net zero emissions vehicles. This study examines the combustion of two such fuels, Dimethyl Ether (DME) and propane, in a compression ignition, 4-cylinder, 2.2L engine running with mixtures of DME-to-Propane ranging of 100%-0%, 85%-15%, 75%-25%, and 65%-35% by weight. Testing was conducted at 2000rpm - 100Nm, an important representative point in the FTP certification cycle. For each fuel mixture, conditions tested include sweeps of boost, EGR and injection pressure. Tests are mainly conducted at a constant combustion timing with CA10 of -1 deg with respect to TDC, with an engine controller combustion feedback system based on in-cylinder sampling of pressure. Trends of NOx, HC, and CO are similar for the range of DME-to-propane, from 100%-0% to 75%-25%. Boost and injection pressures had the most notable impact on the heat release traces. Higher boost, from

De Ojeda, William, Wu, Simon (Haibao), Hall, Carrie, Ankobea-Ansah, King, Hassan, Hafiz Ahmad, Harrison, Christopher

Experimental Study of DOC-on-Filter Using Next Generation Filter Solutions for Non-Road Applications

2025-01-8479

04/01/2025

Upcoming California Tier 5 non-road limits mandate 90% and 75% reductions in NOx and PM respectively, from current Tier 4F emission standards. Similarly, lower NOx and PN/PM limits can be expected from a next round of European Non-Road regulations. To meet these limits, more SCR volume for greater NOx reduction, and better filtration efficiency filters for greater PN/PM reduction, may be required. The challenge is to accommodate larger SCR volume while maintaining oxidation (DOC) and filtration (DPF) functionality of the aftertreatment system within a limited packaging space on non-road machineries. Consolidating DOC and DPF into a single component as DOC-on-filter instead of separate DOC and DPF substrates to achieve space saving has been previously discussed in literature. This study expands on the current understanding and explores various functional performance characteristics of the DOC-on-filter concept in comparison with DOC + bare DPF, DOC + PGM coated DPF. The three test

Dam, Mrinmoy, Warkins, Jason, He, Suhao

Gasoline Particulate Filter Modeling with Catalytic Washcoat and Ash Accumulation and Transient Soot Distribution Prediction

2025-01-8483

04/01/2025

The upcoming EURO 7 and EPA Tier 4 regulations and the possible China 7 are expected to tighten the tailpipe particulate emissions limits significantly. High performance Gasoline Particulate Filters (GPFs) with high filtration efficiency and low pressure drop would be mandated for gasoline engines to meet these stringent regulations. Due to packaging constraints, GPFs are often coated with three-way catalyst (TWC) materials to achieve four-way functionality. Ash accumulation in GPFs also has a significant impact on the performance of GPFs. This paper utilizes 3D CFD to predict the transient filtration efficiency and pressure drop of a washcoated GPF with ash accumulation during the soot loading process. Simulation results show a decent match with experimental data. The 3D CFD model also provides detailed information on soot penetration in the GPF wall substrate and soot cake characteristics on the wall. These information can be crucial for GPF wall substrate design and washcoating

Yang, Pengze, Cheng, Zhen

Consistent Drag Prediction with CFD for a Vehicle with Bimodal Wake Cycling

2025-01-8766

04/01/2025

The vehicle wake region is of high importance when analyzing the aerodynamic performance of a vehicle. It is characterized by turbulent separated flow and large low-pressure regions that contribute significantly to drag. In some cases, the wake region can oscillate between different modes which can pose an engineering challenge during vehicle development. Vehicles that exhibit bimodal wake behavior need to have their drag values recorded over a sufficient time period to take into account the low frequency shift in drag signal, therefore, simulating such vehicle configurations in CFD could consume substantial CPU hours resulting in an expensive and inefficient vehicle design iterations process. As an alternative approach to running simulations for long periods of time, the impact of adding artificial turbulence to the inlet on wake behavior and its potential impact on reduced runtime for design process is investigated in this study. By adding turbulence to the upstream flow, the wake

DeMeo, Michael, Parenti, Guido, Martinez Navarro, Alejandro, Shock, Richard, Fougere, Nicolas, Razi, Pooyan, Oliveira, Danilo, Lindsey, Craig, Yu, Chenxing, Breglia Sales, Flavio

Minimum Standard for Portable Gaseous, Oxygen Equipment

AS1046C (Current)

03/27/2025

This standard is intended to apply to portable compressed gaseous oxygen equipment. When properly configured, this equipment is used either for the administration of supplemental oxygen, first aid oxygen or smoke protection to one or more occupants of either private or commercial transport aircraft. This standard is applicable to the following types of portable oxygen equipment: a Continuous flow 1 Pre-set 2 Adjustable 3 Automatic b Demand flow 1 Straight-demand 2 Diluter-demand 3 Pressure-demand c Combination continuous flow and demand flow.

A-10 Aircraft Oxygen Equipment Committee

Optimization of Abrasive Water Jet Machining of Al 6061-T6 Alloy Using Taguchi-Based Gray Relational Analysis-Coupled Principal Component Analysis Hybrid Approach

05-18-03-0023

03/13/2025

Abrasive water jet (AWJ) machining is the most effective technology for processing various engineering materials particularly difficult-to-cut materials such as aluminum alloys, steels, brass, ceramics, composites, and the like. The present study focuses on the experimental study on surface roughness and kerf taper is carried out during AWJ machining of Al 6061-T6 alloy with 40 mm thickness, and the influence of process parameters includes water jet pressure, standoff distance, and abrasive flow rate on the kerf taper and surface roughness is analyzed. The number of experiments is designed using Taguchi’s L9 orthogonal array. Experimental results are statistically analyzed using ANOVA. Also gray relational analysis (GRA) coupled with principal component analysis (PCA) hybrid approach was implemented to optimize the performance parameters. From the results it is found that standoff distance and hydraulic jet pressure are the most influencing parameters on surface roughness and kerf

Kolluri, Siva Prasad, Srikanth, V., Ismail, Sk., Bhanu, C.H.

CFD-Based Comfort Parameter Evaluation of a Flow Vectoring Air Vent System for Car Cabins Using a Reduced Order Model

15-18-02-0012

03/03/2025

This computational fluid dynamics (CFD) study examines the comfort parameters of an innovative air vent concept for car cabin interiors using a reduced order model (ROM) and proper orthogonal decomposition (POD). The focus is on the analysis of the influence of geometric and fluid mechanical parameters on the resulting jet, in particular on the deflection angle of the airflow and the total pressure difference along the outlet geometry. Different parameters of the investigated system, such as the surface orientation, the outlet height, the separator distance, and the separator height, lead to different effects on the airflow structure. The results show that changes in the air vent surface orientation are always accompanied by an increase in the deflection angle and the total pressure difference. In contrast, the variation of the outlet height ratio positively influences the deflection angle and the total pressure difference in terms of the requirements for air vent geometries. The study

Langhorst, Sebastian, Mrosek, Markus, Boughanmi, Nesrine, Schmeling, Daniel, Wagner, Claus

A Color-Based Sensor Emulates Skin’s Sensitivity

TBMG-52637

03/01/2025

Robotics researchers have already made great strides in developing sensors that can perceive changes in position, pressure, and temperature — all of which are important for technologies like wearable devices and human-robot interfaces. But a hallmark of human perception is the ability to sense multiple stimuli at once, and this is something that robotics has struggled to achieve.

A Comparative Study on the Working Efficiency of Journal Bearing Employing Different Micro-Textures

04-18-02-0011

02/19/2025

This study proposed the different micro-textures of the SC (square cylinder), SWS (square wedge shape), HS (hemispherical shape), and CR (cylindrical round) to improve the working efficiency of the journal bearing. A hydrodynamic lubrication model of the journal bearing under the impact of the changing dynamic loads is established to analyze the performance of micro-textures. The maximum oil film pressure and minimum frictional force in the journal bearing are selected as two evaluation indices. Some outstanding research results show that all the SC, SWS, HS, and CR added on the bearing surface improved the working efficiency of the journal bearing better than without the micro-textures. Moreover, the HS also improved the working efficiency of the journal bearing better than other structures of SC, SWS, and CR. To optimize the working efficiency of the journal bearing using HS, the dimension ltex and depth htex of HS should be selected and designed in a range of 3.6 < ltex ≤ 3.9 mm and

Song, Fengxiang, Nguyen, Vanliem, Liu, Yaxi

Quantifying Hydroplaning Risk: Insights from Water Film Thickness Measurements on Maryland Highways

02-18-02-0010

02/19/2025

Wet pavement conditions during rainfall present significant challenges to traffic safety by reducing tire–road friction and increasing the risk of hydroplaning. During high-intensity rain events, the roadway pavement tends to accumulate water, forming a film that can have serious implications for vehicle control. As the longitudinal speed of the vehicle increases, a water wedge forms in front of the tire, leading to partial loss of contact with the road. At critical hydroplaning speed, a complete water layer forms between the tire and the road. Although less common, dynamic hydroplaning poses severe risks when high-intensity rainfall coincides with high vehicle traveling speed, leading to a complete loss of control over vehicle steering capabilities. This study advances hydroplaning research by integrating real-world data from the Road Weather Information System (RWIS) with an existing hydroplaning model. This approach provides more accurate hydroplaning risk assessments, emphasizing

Vilsan, Alexandru, Sandu, Corina, Anghelache, Gabriel

Enhancing Flow and Heat Transfer Characteristics in Microchannels with Various Nanofluids

2025-28-0024

02/07/2025

The substantial growth of power converters in electric vehicles necessitates more energy consumption and, as a result, greater heat generation. To avoid the power converter’s excessive heat, an innovative curved microchannel with diamond-shaped and pentagonal cross-sections was developed. The flow and heat transfer characteristics of the Gc3N4/Water (0.3%), Al2O3/Water (0.3%), and Al2O3-Gc3N4/Water (0.3%) hybrid nanofluid were assessed. The experimental investigation was carried out by different mass flow rates of about 0.1 to 0.5 LPM under a uniform heat flux of 50 kW/m2. The heat sink had a cross-sectional area of 80×48mm2. In comparison to the diamond channel heat sink through hybrid nanofluids, findings from experiments resulted that the heat transfer rate and pressure drop for the diamond channel enhanced by 14.2% and 18.9%, respectively. In comparison to Gc3N4/Water and Al2O3/Water nanofluids, the hybrid nanofluid improved the heat transfer rate for the diamond micro channel heat

R L, Krupakaran, Petla, Ratna Kamala, Anchupogu, Praveen, Kala, Lakshmi K, Gangula, Vidyasagar Reddy, Tarigonda, Hariprasad

A Novel Approach to develop the Exhaust Backpressure Measurement System for Automotive Application

2025-28-0168

02/07/2025

Backpressure is one of key acoustic performance evaluation criteria of exhaust muffler (or Silencer) /EATS (Exhaust after treatment system) as well as for the exhaust system. Exhaust back pressure is an important parameter for fuel efficiency of a vehicle. Typically, the engine manufacturer specifies an upper limit for this. Usually, exhaust back pressure is measured during the driving condition of the vehicle at maximum power condition of the engine either on road or on chassis dynamometer. Both these methods, need a lot of preparatory works, test setup arrangement, 3 or more manpower and special skills. In this research, authors are tried to develop a new backpressure measurement set up for automotive vehicle application, which is simple and innovative, to fulfill the backpressure test requirement. In this design, mainly following devices are used namely Pitot tube, Compressed air, Manometer (or pressure gauge), Thermocouple, Fluke thermometer, along with standalone exhaust layout

Mandal, Goutam, Biswas, Sanjoy

CFD Analysis on the Effect of Circular Cavity at Different Location of Airfoil Surface

2025-28-0074

02/07/2025

The paper present numerical effects of supercritical airfoil SC (2) 0414 having circular cavities at three different chord wise locations from leading to trailing edge. Here passive control method is widely applied by altering the \baseline airfoil surface coordinates to ascertain the aerodynamic behavior of the cavity at 40 %, 50 % and 60 % of the chord length respectively. The cavity shapes were deformed using Bezier curve to observe vortex pattern in the cavity region. Structured meshing was employed. The analysis was performed on SC 2 (0) 414 two-dimensional airfoil using commercial CFD ANSYS Fluent software where Spalart- Allmaras turbulence model technique is chosen to solve boundary layer problems on adverse pressure gradient and tested at extended range of angle of attack (-150 to 150) at Mach number 0.85. The study highlights the aerodynamic characteristics of lifting coefficient, drag coefficient and lift to drag ratio. It was observed that the cavity in suction surface

Pushparaj, Catherine Victoria, P, Booma Devi, D, Piriadarshani, Ganesan, Balaji, Ganesan, Santhosh Kumar, Raja, Vijayanandh

Cryogenic Flux Capacitor

TBMG-52477

02/01/2025

NASA's Cryogenic Flux Capacitor (CFC) capitalizes on the energy storage capacity of liquefied gases. By exploiting a unique attribute of nano-porous materials, aerogel in this case, fluid commodities such as oxygen, hydrogen, methane, etc. can be stored in a molecular surface-adsorbed state. This cryogenic fluid can be stored at low to moderate pressure densities, on par with liquid, and then quickly converted to a gas, when the need arises. This solution reduces both safety-related logistics issues and the limitations of complex storage systems.

Research of Pressure Control Based on Dither

2025-01-7040

01/31/2025

The purpose of the paper is to study the impact of dither on how to improve the pressure control capability in common rail system. The dither is directly operating to the inlet metering valve and making the metering flow accuracy. The correlation between rail pressure and metering flow was analyzed. Optimizing the inlet metering valve control is to improve the pressure control. To overcome the hysteresis problem of the inlet metering valve and improve its stability and rapidity on the pressure control. The PID control strategy based on the pressure control were applied in the common rail system and many papers have introduced the logical. But the dither application was seldom introduced in the common rail system. The dither was specified for the inlet metering valve. With the proper dither signal, the stick-slip motion of the metering valve spool converted to a steady one and the dynamic performance was optimized. To verify the theoretical and calibrated the proper dither signal, the

Kuang, Pengda, Chen, Huiqing, Zhang, Jing, Ran, Ye

Effect of Gasification Temperature on Biohydrogen Derived from Waste Agro Products for Alternative Fuel Application

2024-01-5260

01/28/2025

Hydrogen fuel is becoming a popular choice in many energy applications because of its innovative green technology, which produces zero carbon emissions. It also offers better efficiency than fossil fuels. Current research focuses on obtaining hydrogen energy from agricultural waste using a gasification process. This process involves heating the waste at gasification temperatures 300, 400, 500, 600, and 700°C, maintaining a residence time of 60 minutes, and applying a gasification pressure of 20 bar. The effects of gasification temperature on the effectiveness of hydrogen production are examined. At a high gasification temperature of 700°C and a residence time of 60 minutes, the processed agro feedstock showed impressive results. It achieved a molar fraction of 12% carbon dioxide (CO2), 31% methane (CH4), and 55% hydrogen (H2), leading to an improved hydrogen yield of 15.2 mol/kg. Additionally, it demonstrated better hydrogen selectivity at 8.1 and a higher gasification efficiency of 61

Venkatesh, R., De Poures, Melvin Victor, Raguraman, B., Marimuthu, S., Devanathan, C., Baranitharan, Balakrishnan, Madhu, S., Kaliyaperumal, Gopal, Manickaraj, Pethuraj

A Comparative Study of Combustion and Performance in Diesel Engines Fueled by Mosambi Peel Biodiesel-Butylated Hydroxytoluene Nanoparticles Blend

2024-01-5258

01/28/2025

This study’s objective is to examine the combustion and performance of mosambi waste peel biodiesel (MWPB) combined with butylated hydroxytoluene (BHT) nanoparticles as a substitute fuel for diesel engines. It also aims to assess the impact of this blend on engine combustion, such as in-cylinder pressure, heat release rate (HRR), ignition delay (ID), combustion duration (CD) and mass fraction burnt (MFB) and performance indicators, including brake thermal efficiency (BTE), brake-specific energy consumption (BSEC), engine torque, exhaust gas temperature (EGT), indicated mean effective pressure (IMEP), air-fuel ratio (A/F ratio) and volumetric efficiency, while also considering the feasibility of employing waste materials in fuel generation. The experimental configuration utilized a research diesel engine functioning under standard conditions, emphasizing the maintenance of uniform injection pressure to ensure optimal fuel atomization and combustion. The test fuels are diesel, MWPB, MWPB

Jayabal, Ravikumar, Madhu, S., Devarajan, Yuvarajan, Domian, Christopher Selvam

Pressure-Dependent Nonlinearities of a Compact Hydropneumatic Strut with Integrated Gas–Oil Chamber

10-09-01-0008

01/24/2025

Hydropneumatic Struts (HPS) are widely implemented in automobile, aerospace, and construction industries, mainly for the purpose of vibration and shock absorption. The HPS design with integrated gas–oil chamber is relatively more compact and robust, while mixing gas and oil inside the HPS generates gas–oil emulsion and more nonlinearities. This study formulated a nonlinear analytical model of the compact HPS with gas–oil emulsion, considering the real gas law and pressure-dependent LuGre friction model. The polytropic version of the van der Waals (vdW) method for real gas is applied to represent the thermodynamic behavior of nitrogen. The experimental data were collected at a near temperature of 30°C with three charging pressures under excitations in the frequency range of 0.5–6 Hz, considering two flow connection configurations between chambers as one- and two-bleed orifice. The nonlinear behavior of the gas volume fraction of the emulsion was identified based on peak strut velocity

Seifi, Abolfazl, Yao, Yumeng, Yin, Yuming, Moore, Masih, Rakheja, Subhash

Aerospace - Evaluation of Particulate Contamination in Hydraulic Fluid - Membrane Procedure

ARP4285A (Current)

01/09/2025

This SAE Aerospace Recommended Practice (ARP) establishes a method for evaluating the particulate matter extracted from the working fluid of a hydraulic system or component using a membrane. The amount of particulate matter deposited on the membrane due to filtering a given quantity of fluid is visually compared against a standard membrane in order to provide an indication of the cleanliness level of the fluid.

A-6C1 Fluids and Contamination Control Committee

The Use of Pressure Constructs in Aerodynamics May Lead to Misinformation

01-17-03-0020

01/06/2025

From biology, to genetics, and paleontology, these fields share the DNA as a common and time-proven tool. In science, pressure may be such a tool, shared by thermodynamics, material science, and astrophysics, but not by aerodynamics. Pressure is a shorthand for a force acting perpendicular to a surface. When this surface is reduced to zero, so should the pressure. The wing area of an aircraft acts as a reference area to calculate its parasite drag coefficient. In this scenario, the parasite drag acts as a force over the wing area. If the wing area is reduced to zero, its parasite drag does not, as the fuselage is still generating parasite drag. The ratio of the parasite drag and wing area is an example of a pressure construct that uses a physically irrelevant reference area and has no absolute zero. Pressure constructs, more frequently used than pressures in aerodynamics, are a math-based parameter that preserve dimensional propriety according to the Buckingham Pi theorem but lacks a

Burgers, Phillip

Enhancing Engine Lubrication: Design and Evaluation of Oil Sump Surge Control in Racing Vehicles

2024-36-0074

12/20/2024

During accelerations and decelerations of a race car whose engine has a wet sump, the forces generated by the vehicle’s motion cause the engine oil to vigorously shift towards the walls of the oil pan and crankcase, contributing to the phenomenon known as ‘sloshing.’ This phenomenon often leads to fluctuations in oil pressure, resulting in oil pressure surge, when the oil is pushed away from the pump pickup point. Via the logged data, the Formula UFSM FSAE Team had witnessed a recurrent lack of oil pressure in the race track during the 2023 Brazilian FSAE competition. In the AutoCross Event, the recurrence of this problem was 80% of the right corners on lateral accelerations between 0.80G and 1.30G. The average oil pressure in this condition was 0.80 bar, even reaching 0.10 bar above 5000 RPM. Therefore, it was necessary to develop a new set of baffles for the oil pan, capable of minimizing the effects of sloshing and, consequently, the oil surge. As a method of research, a test bench

Zimmermann, Natalia Diovana, Junior, Luiz Alfredo Coelho, Martins, Mario, Hausen, Roberto

Response Surface Methodology-Based Multi-Objective Optimization for Biofuel-Powered Engine Response Map Development under the Steady-State Operating Conditions

03-17-08-0063

12/20/2024

The twin challenges of the automotive industry namely petroleum dependence and environmental pollution paved way for the development of an environmentally friendly and feasible substitute for diesel, possessing power characteristics equivalent to those of a diesel engine. Biofuel has potential as a renewable energy source, offering a more sustainable alternative to traditional fossil fuels. However, it does come with some challenges, such as varying quality and combustion properties. To enhance its performance, engines can be fine-tuned by adjusting fuel injection parameters, such as timing, pressure, and duration. Accordingly, this research article focuses on optimizing the fuel injection parameters for a CRDi engine powered by D+LPO (20% lemon peel oil and 80% diesel) biofuel, with the goal of improving both performance and emission characteristics. The experimental design matrix was generated using Design Expert-13 software, employing the I-optimal technique. Utilizing response

Saiteja, Pajarla, Ashok, B.

2024 Create the Future Design Contest: Medical Category Winner - A Smart Contact Lens for Glaucoma Management

TBMG-52152

12/01/2024

Hamdi Torun Arda Deniz Yalcinkaya Gunhan Dundar Ozgue Kaya Northumbria University, Newcastle Upon Tyne, UK

Smart Contact Lens for Glaucoma Detection

TBMG-52160

12/01/2024

Researchers have been testing ways to continuously and more comfortably detect these tiny fluctuations in pressure. A prototype smart contact lens measures eye pressure accurately, regardless of temperature. The contact lens wirelessly transmits real-time signals about eye pressure across a wide range of temperatures.

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