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Technical Paper

Thermal Analysis of Prismatic Core Sandwich Structural Panel for Hypersonic Application

2024-06-01
2024-26-0422
Hypersonic flight vehicles have potential applications in strategic defence, space missions, and future civilian high-speed transportation systems. However, structural integration has significant challenges due to extreme aero-thermo-mechanical coupled effects. Scramjet-powered air-breathing hypersonic vehicles experience extreme heat loads induced by combustion, shock waves and viscous heat dissipation. An active cooling thermal protection system for scramjet applications has the highest potential for thermal load management, especially for long-duration flights, considering the weight penalty associated with the heavier passive thermal insulation structures. We consider the case of active cooling of scramjet engine structural walls with endothermic hydrocarbon fuel. We have developed a semi-analytical one-dimensional heat transfer model considering a prismatic core single cooling channel segment as a representative volume element (RVE) to analyse larger scale problems.
Technical Paper

Knockdown Factor Estimation of Stiffened Cylinders under Combined Loads - A Numerical Study

2024-06-01
2024-26-0417
Airframe section of rockets, missiles and launch vehicles are typically cylindrical in shape. The cylindrical shell is subjected to high axial load and an external pressure during its operation. The design of cylinders subjected to such loads is generally found to be critical in buckling. To minimize the weight of cylinders, it is typically stiffened with rings and stringers on the inner diameter to increase the buckling load factor. Conventionally the buckling load estimated by analytical or numerical means is multiplied by an empirical factor generally called Knockdown factor (kdf) to get the critical buckling load. This factor is considered to account for the variation between theory and experiment and is specified by handbooks or codes. In aerospace industry, NASA SP 8007 is commonly followed and it specifies the kdf as a lower bound fit curve for experimental data .
Technical Paper

Assessing the Effects of Computational Model Parameters on Aerodynamic Noise Characteristics of a Heavy-Duty Diesel Engine Turbocharger Compressor at Full Operating Conditions

2024-04-09
2024-01-2352
In recent years, with the development of computing infrastructure and methods, the potential of numerical methods to reasonably predict aerodynamic noise in compressors has increased. However, aerodynamic acoustic modeling of complex geometries and flow systems is currently immature, mainly due to the greater challenges in accurately characterizing turbulent viscous flows. Therefore, recent advances in aerodynamic noise calculations for automotive turbocharger compressors were reviewed and a quantitative study of the effects for turbulence modeling (Shear-Stress Transport (SST) and Detached Eddy Simulation (DES)) and time-steps (2°and 4°) in numerical simulations on the performance and acoustic prediction of a compressor under full operating conditions was investigated. The results showed that for the compressor performance, the turbulence models and time-step parameters selection were within 1.5% error of the simulated and measured values for pressure ratio and efficiency.
Technical Paper

Evaluating the effects of an Electrically Assisted Turbocharger on scavenging control for an Opposed Piston Two Stroke (OP2S) compression ignition engine

2024-04-09
2024-01-2388
Opposed piston two-stroke (OP2S) diesel engines have demonstrated a reduction in engine-out emissions and increased efficiency compared to conventional four-stroke diesel engines. Due to the higher thermal efficiency and absence of a cylinder head, the heat transfer loss to the coolant is lower near the ‘Top Dead Center’. The selection and design of the airpath are pivotal in realizing the benefits of the OP2S engine architecture. Like any two-stroke diesel engine, the scavenging process and the composition of the internal residuals are predominantly governed by the pressure differential between the intake and the exhaust ports. Moreover, a significant portion of the work involved in pumping air is carried out externally to the engine cylinder which needs to be accounted for when calculating brake efficiencies.
Technical Paper

3-Dimentional Numerical Transient Simulation and Research on Flow Distribution Unevenness in Intake Manifold for a Turbocharged Diesel Engine

2024-04-09
2024-01-2420
The design of engine intake system affects the intake uniformity of each cylinder of the engine, which in turn has an important impact on the engine performance, the uniform distribution of EGR exhaust gas and the combustion process of each cylinder. In this paper, the constant-pressure supercharged diesel engine intake pipe is used as the research model to study the intake air flow unevenness of the intake pipe of the supercharged diesel engine. The pressure boundary condition at the outlet of each intake manifold is set as the dynamic pressure change condition. The three-dimensional numerical simulation of the transient flow process in the intake manifold of diesel engine is simulated and analyzed by using numerical method, and the change of the internal flow field in the intake manifold under different working conditions during the intake overlapping period is discussed.
Technical Paper

A Preliminary Study on the Evaporative Cooling System for FCEV

2024-04-09
2024-01-2406
Recently, fuel cell stacks have been applied to various fields, and the importance of thermal energy management is increasing along with the increase in required power and heat dissipation. In particular, research and development is underway to improve various performance due to FCEV characteristics with a lower cooling temperature than ICE. Therefore, it is essential to develop a new cooling system to overcome these limitations. This study is a prior study to develop the evaporative cooling system by using water as a by-product of the stacks, and aims to identify the effects of variables affecting the performance. The commercial codes were used to simulate the quantitative sprayed area for actual evaluations. The sprayed area was chosen as a key indicator of cooling performance from the viewpoint of evaporation rate, which is well known to be proportional to the evaporation effect on the surface of the fin.
Technical Paper

Research on the Flow and Heat Exchange Performance of the Chiller for Electric Vehicles

2024-04-09
2024-01-2412
A two-particle lumped parameter model was developed for the chiller, and an experimental device was built to measure flow and heat exchange of the chiller. Empirical correlations for the convective heat transfer coefficients on both the coolant and refrigerant sides were obtained by fitting the experimental data. The influence of herringbone corrugated plate parameters, including angle, pitch, and depth, on performance of chillers at different Reynolds numbers (Re) was investigated. In modeling of a chiller two-phase and overheated zones of the refrigerant are considered simultaneously, and their respective areas were calculated to enhance the accuracy of the model. Using the Wilson plot method in experimental design, the convective thermal resistance of heat transfer on both sides was separated from the total thermal resistance to determine the actual coefficient of convective heat transfer.
Technical Paper

Control Strategy for Engine Silicone Oil Fan Clutch Based on Engine Cooling System

2024-04-09
2024-01-2234
In order to study the influence of engine silicone oil fan clutch on the performances of engine cooling system under different control strategies, a model of engine cooling system for commercial vehicle is established. The working characteristics of the silicone oil clutch and the measured performance parameters of the cooling system components are taken into account in our proposed model. Modeling methods for different silicone oil fan control strategies are also given. Using the established model, the performance parameters under different vehicle speeds, such as engine outlet coolant temperature and cooling fan power consumption, are calculated and analyzed. The in-suite measurement of the engine cooling system is carried out to get the temperatures of engine inlet and outlet from engine ECU. The model is validated by the comparison between the calculation and the measured results.
Technical Paper

1D Modeling Approach for Prediction of Heat Transfer in Aftertreatment System and Sensors Module

2024-04-09
2024-01-2739
The study of temperature distribution and heat transfer over non-uniform geometry is of great importance to engineers because of universal occurrence in many engineering applications such as diesel engine, boilers, heaters, radiators, dosers, etc. Performance of engine and its components (mechanical and electronic) is highly depending upon efficient thermal management. An accurate heat transfer analysis is necessary in automotive application and power plant. This study presents one dimensional model for prediction of conjugate heat transfer in Aftertreatment system and Sensors Module (Nox Sensor, PM Sensor, EGTS etc..) for diesel engine. Three-dimensional conductive, convective and radiative thermal analysis is computationally expensive as underhood models are of complex shape in nature and total turnaround time for product development project is also significantly high.
Technical Paper

Representative Cyclist Collision Injury Risk Distributions for a Dense-Urban US ODD Using Naturalistic Dash Camera Data

2024-04-09
2024-01-2645
Automated driving systems (ADS) are designed toward safely navigating the roadway environment, which also includes consideration of potential conflict with other road users. Of particular concern is understanding the cumulative risk associated with vulnerable road users (VRUs) conflicts and collisions. VRUs represent a population of road users that have limited protection compared to vehicle occupants. These severity distributions are particularly useful in evaluating ADS real-world performance with respect to the existing fleet of vehicles. The objective of this study was to present event severity distributions associated with vehicle-cyclist collisions within an urban naturalistic driving environment by leveraging data from third-party vehicles instrumented with forward-facing cameras and a sensor suite (accelerometer sampling at 20 Hz and GPS [variable sampling frequency]). From over 66 million miles of driving, 28 collision events were identified.
Technical Paper

Investigation of Propagation of Viruses and Risk of Infection in Automobile Cabins

2024-04-09
2024-01-2579
The author has developed UV based photocatalytic air purification system (Mathur, 2021, 2023) that can eliminate all pathogens from the cabin air including COVID-19. In this study, the focus is to determine the risk of infection due to pathogens/germs in the cabin of an automobile. Author has determined the risk of infection by using Wells-Riley model and the conducted CFD analysis to determine propagation of virus in cabin.: 1. Cabin Volume & Number of Occupants (Wells-Riley Model in OSA mode): (i) Cabin volume from: Small Sedan, Large Sedan and a SUV; with 4 occupants (males & females); Number of infector 1; Air flowrate (m3/min); (ii) A 15-seater minibus - with 10 occupants(males); Number of infectors 1 & 2; Air flowrate (m3/min) 2.
Technical Paper

Analysis of Dual Fuel Hydrogen/Diesel Combustion Varying Diesel and Hydrogen Injection Parameters in a Single Cylinder Research Engine

2024-04-09
2024-01-2363
In the perspective of a reduction of emissions and a rapid decarbonization, especially for compression ignition engines, hydrogen plays a decisive role. The dual fuel technology is perfectly suited to the use of hydrogen, a fuel characterized by great energy potential. In fact, replacing, at the same energy content, the fossil fuel with a totally carbon free one, a significant reduction of the greenhouse gases, like carbon dioxide and total hydrocarbon, as well as of the particulate matter can be obtained. The dual fuel with indirect injection of gaseous fuel in the intake manifold, involves the problem of hydrogen autoignition. In order to avoid this difficulty, the optimal conditions for the injection of the incoming mixture into the cylinder were experimentally investigated. All combustion processes have been carried out on a research engine with optical access. The engine speed has been set at 1500 rpm, while the EGR valve has been deactivated.
Technical Paper

Study and Analysis on 3-Dimensional Simulation of The Transient Flow Process of Engine Electronic Control Throttle

2024-04-09
2024-01-2417
Based on the basic structure and operation function of engine throttle, according to the actual structure of a throttle, a 3-dimensional simulation of the transient airflow during the rotation of the throttle from the closed position to the fully open position is realized by using CFD together with the moving mesh technology and the user-defined program. The influence of the throttle movement on the airflow process is studied. The velocity field, pressure field, and flow noise field are analyzed at different angles of throttle rotation. The numerical simulation results show that at the beginning period of the throttle rotation, the vortex appears in the flow field behind the throttle, and the drop of the air pressure between the front and back of the throttle is sharp.
Technical Paper

Impact of Injection Valve Condition on Data-driven Prediction of Key Combustion Parameters Based on an Intelligent Diesel Fuel Injector for Large Engine Applications

2024-04-09
2024-01-2836
The advent of digitalization opens up new avenues for advances in large internal combustion engine technology. Key engine components are becoming "intelligent" through advanced instrumentation and data analytics. By generating value-added data, they provide deeper insight into processes related to the components. In addition, these data form the basis for novel condition monitoring, predictive maintenance and controls approaches. Changes to the intelligent component’s operational characteristics due to wear or faults pose a particular challenge for developers of such approaches for later series application. A previous study has already demonstrated that an intelligent common rail diesel fuel injection valve for large engine applications in combination with machine learning allows reliable prediction of key combustion parameters such as maximum cylinder pressure, combustion phasing and indicated mean effective pressure.
Technical Paper

Fully Retractable Easy Access Spare Wheel Carrier Mechanism for Commercial Vehicles.

2024-04-09
2024-01-2225
In today's market practise & standard mechanism being provided from OEM, tyre changing mechanism is a tedious job, took long time & much higher efforts in Indian trucking industry harsh environments. Heavy commercial vehicles are fitted with spare wheel carrier that has a rope mechanism to load and unload the spare wheel. The mounting of this system is generally on side of frame/ chassis or within the limits of side member. The invention reduces effort and time required to remove spare tyre. The invention brings the spare wheel to a vertical position where it is easy to remove its bolts and remove it from its mountings. Also, this innovative mechanism is well supported by 3 way actuation system (Air Actuated system, Electric motor driven system or Hydraulic cylinder actuated mechanisms), which reduced human efforts and gives benefit to drivers in terms of comfort.
Technical Paper

Humidity Controlled Evaporative Cooler for Cooling of Automotive Cabin.

2024-04-09
2024-01-2580
The invention discussed here is based on the evaporative cooling of vehicle cabin with novel concept of humidity control. The conventional Air Conditioning (AC) system operated on Vapour Compression Refrigeration Cycle (VCRC) is costly and leads to higher fuel consumption due to use of compressor which is driven by engine of automobile. Currently there is no other OEM fitted cabin cooling option to address this issue. This innovation suggest the idea of humidity controlled evaporative cooler is introduced in current work. The goal of humidity control is achieved with the help of controller unit which takes feedback from humidity sensor and further regulates the water pump operation. The ambient air is passed through the humidified honeycomb pad and thus gets cool by the principle of evaporation. A polyester nonwoven filter has also been introduced in the system to restrict the entry of any leftover water droplets into the cabin.
Technical Paper

Effect of Port Water Injection on the Knock and Combustion Characteristics of Argon Power Cycle Hydrogen Engine

2024-04-09
2024-01-2612
Argon power cycle hydrogen engine is the internal combustion engine that employs argon instead of nitrogen of air as the work mass, oxygen as the oxidizer, and hydrogen as the fuel. Since argon has a higher specific heat ratio compared to air, argon power cycle hydrogen engines have theoretically higher indicated thermal efficiencies according to the Otto cycle efficiency formula. However, argon makes the end mixture more susceptible to spontaneous combustion, and thus is accompanied by stronger knock at a lower compression ratio, thus limiting the improvement of thermal efficiency in engine operation. In order to suppress the limitation of knock on the thermal efficiency, this paper adopts a combination of experimental and simulation methods to investigate the effects of port water injection on the knock suppression and combustion characteristics of an argon power cycle hydrogen engine.
Technical Paper

New Solution for Material Damage Characterization of CFRP Laminate with Filament Winding Structure Using a Hexagonal-Shaped Mandrel

2024-04-09
2024-01-2884
CFRP manufactured by a filament winding process has a unique laminate structure. So far, a material damage model applied to design CFRP component manufactured by FW process was identified using a material property of a CFRP flat plate laminated unidirectionally with predetermined angle. However, from these material properties the effect of filament winding structure cannot be evaluated nor can be introduced to the material model. In this study, a newly hexagonal shaped mandrel with flat parts on the cylinder and dome region of the high-pressure vessel was devised and a procedure of a flat plate laminate with filament winding structure was proposed. Filament winding structure on a flat surface by this method matched well with that of the curved surface simulated by ComposCad. In addition, the FEM simulation result of meso-scale laminate coupon model using material damage model obtained from material property of coupon matched well with the experimental result. 
Technical Paper

Post-Oxidation Phenomena as a Thermal Management Strategy for Automotive After-Treatment Systems: Assessment by means of 3D-CFD Virtual Development

2024-04-09
2024-01-2629
The target of the newly and future automotive emission regulations is to promote a fast transition to near-zero emission vehicles. As such, the range of ambient and operating conditions tested in the homologation cycles is broadening. In this context, the proposed work aims to thoroughly investigate the potential of post-oxidation phenomena in reducing the light-off time of a conventional three-way catalyst. The study is carried out on a turbocharged four-cylinder gasoline engine by means of experimental and numerical activities. Post oxidation is achieved through the oxidation of unburned fuel in the exhaust line, exploiting a rich combustion and a secondary air injection dedicated strategy. The CFD methodology consists of two different approaches: the former relying on a full-engine mesh, the latter on a detailed analysis of the chemical reactions occurring in the exhaust line.
Technical Paper

Virtual Chip Test and Washer Simulation for Machining Chip Cleanliness Management Using Particle-Based CFD

2024-04-09
2024-01-2730
Metal cutting/machining is a widely used manufacturing process for producing high-precision parts at a low cost and with high throughput. In the automotive industry, common engine components such as cylinder heads or cylinder blocks are all manufactured using such processes. Despite its cost benefits, manufacturers often face the problem of machining chips and cutting oil residue remaining on the finished surface after machining operations, and these wastes can be very difficult to clean. While part cleaning/washing equipment suppliers often claim that their washers have superior performance, determining the washing efficiency is challenging without knowledge of chip clogging locations and water jet flow patterns. In this paper, a virtual engineering methodology using particle-based CFD is developed to manage the metal chip cleanliness issue resulting from engine component machining operations. This methodology comprises two simulation methods.
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