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A quasidimensional engine simulation which uses the concepts of fractal geometry to model the effects of turbulence on flame propagation in a homogeneous charge SI engine has been developed. Heat transfer and blowby/crevice flow submodels are included in this code and the submodels chosen are found to be reasonable. The model predictions of cylinder pressure histories are then compared with experimental data over a range of loads, equivalence ratios, and engine speeds. The model is not adjusted in any manner to yield better agreement with the data, other than by tuning the simple turbulence model used so as to yield agreement with data for the nonreacting flow. However, current information about the flame wrinkling scales in an engine is inadequate. Therefore, predictions are made for three different assumptions about the flame wrinkling scales which span the range of physically possible scales.

In this investigation the in-cylinder flow field structure was evaluated in a small displacement (50 CC) two-stroke spark-ignition engine using cylinders with Schnuerle-ports and a boost-port. A special hot-wire probe was designed, fabricated and calibrated for the use in this work. A constant temperature hot-wire anemometer was used for measurements. The effects of speed, throttle position and piston head shape were studied. The effect of compression ratio, silencer shape and inclusion of resonator to the engine induction and exhaust systems on the in-cylinder flow field activity in the Schnuerle-ported cylinder were analysed. The flow field conditions at different downward locations in the axial direction from the spark point were also evaluated in the Schnuerle-ported cylinder.

The fossil fuel is consumed faster than last century. However, the fossil fuel reserves might be depleted due to its limited resources. Many researchers have started to seek alternative of fossil fuels for vehicles. Biofuels are regarded as a shorten-solution which synthesizes some additive fuel from bio-materials into fossil fuel to reduce fossil fuel consumption and can be applied on original fuel supplying system of vehicles that becomes another advantage. This paper focuses on studying the operation characteristics of using gasohol biofuel in a production motorcycle engine. Engine experiments with various test conditions are designed to investigate the operation characteristics with different concentration of ethanol. The ethanol concentrations considered in this paper include 10%, 20%, 50%, 65%, and 80% by weight, which are then compared with the results from pure gasoline.

Air motion in a cylinder in a compression ignition engine affects on mixing of air-fuel, quality of combustion and emission produced. With upcoming stringent norms for diesel engines, it is necessary to enhance air-fuel mixing for proper combustion. Swirl and tumble are forms of air motion. Swirl is a rotational motion of a bulk mass within cylinder. Swirl is generated by shaping and countering intake manifold and valve ports. Swirl enhances air-fuel mixing and helps to spread flame-front during combustion. The objective of this paper is to analyze the impact of different swirl ratios on NOx and soot emission characteristics inside the cylinder of a DI Diesel engine. The effects of different geometrical parameters of helical port were studied and the swirl ratios are optimized by optimizing the geometrical parameter of helical port. This can be done by different manufacturing, polishing and grinding processes.

The original Table 2 includes incorrect data under the "Primary Energy" column for "multi-strike", "continuous" and "plasma" system types.

An inadequate sealing of the combustion chamber gasket interface may have severe consequences on both the performance & emission of an engine. In this investigation, both the distribution of the contact pressure on the gasket and the stresses of the cylinder head at different loading conditions are explored and improved by modifying the design. A single cylinder gasoline engine cylinder head assembly has been analyzed by means of an uncoupled FEM simulation to find the sealing pressure of the multi-layer steel (MLS) gasket, strength & deformation of the components involved. The thermal loads are computed separately from CFD simulations of cylinder head assembly. The cylinder head assembly consisting of head, blocks, liner, cam shaft holder, bolts, gaskets, valve guides & valve seats, is one of the most complicated sub-assembly of an IC engine.

As part of EcoCAR 3 competition, the California State University, Los Angeles team is designing a Parallel Post Transmission Plug-in Hybrid Electric Vehicle based on a 2016 V6 Chevrolet Camaro. The redesigned vehicle shall maintain or exceed consumer acceptability in performance, utility and safety while reducing Well-to-Wheel Green House Gas emissions. Two control strategies in which the vehicle would operate are being developed: main and modified hybrid control algorithms. The modified control strategy introduces the optimized operating strategy in which the lower emissions and longer engine and battery life are achieved. The vehicle model was developed using Autonomie software and the simulation results with the main and new modified control strategy are also presented.

Varying valve actuation in an IC Engine as per the requirement at different engine speeds using Mechanical Variable Valve Management Module. This innovative mechanism can be implemented in all types of Valve trains generally used in two wheeler engines. Standard valve trains has got one cam lobe each to actuate inlet and exhaust Valves to achieve defined constant valve timings. Valve timings in this case are defined to have compromised engine performance at low and high speeds. In fact optimum engine performance requires different valve timing for different engine speeds. During low operating speeds of engine it is desired to delay opening of intake valve to reduce the overlap with exhaust valve for stable combustion and avoid mixing residual gases with fresh gases and also close intake valve early to reduce back flow resulting in increased volumetric efficiency at low speeds.

Despite considerable advances in predictive maintenance concepts are still largely reserved for only the most critical system components and have not found their place in mainstream machinery health management. Even though there are a number of condition monitoring and analysis techniques, researchers are in search of a simple and easy way to monitoring the condition of an engine, which is an omnipresent and an important power unit in any vehicle or machinery. Vibrations have been the most recent easy to measure condition monitoring. However, this paper will provide the details of diagnostic technologies that can be applied on a single cylinder diesel engine components, and span a continuum of sophistication and rely upon the availability vibration measurement equipments. The vibration measurements are used as monitoring parameters, while single-processing indices are used for diagnosis procedure.

This paper discusses recent improvements made by Honeywell's Condition-Based Maintenance (CBM) Center of Excellence (COE) to Mechanical Health Management (MHM) algorithms. The Honeywell approach fuses Condition Indicators (CIs) from vibration monitoring and oil debris monitoring. This paper focuses on using MHM algorithms for monitoring gas turbine engines. First an overview is given that explains the general MHM approach, and then specific examples of how the algorithms are being refined are presented. One of the improvements discussed involves how to detect a fault earlier in the fault progression, while continuing to avoid false alarms. The second improvement discussed is how to make end of life thresholds more robust: rather than relying solely on the cumulative mass of oil debris, the end of life indication is supplemented with indicators that consider the rate of debris generation.

The hydrogen assisted jet ignition system (HAJI) replaces the spark plug of an Otto cycle engine and consists of a very small pre-chamber into which a hydrogen injector and spark plug are installed. The HAJI system allows stable combustion of very lean main-chamber hydrocarbon mixtures, leading to improved thermal efficiency and very much reduced NOx emissions. The current investigation focuses on the application of HAJI to a modern pent-roof, four valve per cylinder automotive engine. The development of a new hydrogen injection system and HAJI pre-chamber based on proprietary gasoline and diesel injectors is described. Results from injector and engine performance testing are presented in detail.

For vehicle fire investigations, the issue of gasoline hot surface ignition [HSI] on an engine component will arise. To address the concern usually two facts are required; the fluid's lowest hot surface ignition temperature for the vehicle conditions and the temperature of the component surface at the time of the fire origin. Three typical engine compartment surfaces were used to determine the HSI of gasoline; a nodular iron exhaust manifold, a stainless steel exhaust manifold, and a stainless steel heat shield. These components were used to conduct the bench tests for the typical regular and premium, summer and winter gasoline blends. Video tapes were used to acquire accurate autoignition temperature [AIT] data with thermocoupled parts. The investigation determined that the gasoline's HSI minimum values were dependent upon the materials used for the ignition surfaces rather than the grades of gasoline.

The development of ramjet engines has experienced a significant increase in response to the growing demand for supersonic speed capabilities in contemporary propulsion systems and missile weaponry. Their efficient operation at supersonic speeds has garnered increased attention. The study focuses on designing a diffuser and ram cone for decelerating supersonic flow in the combustion chamber. Performance tests for hydrogen and ethanol fuels are conducted at Mach values of 3.5, 3, and 2.5. Injectors are positioned asymmetrically in parallel, perpendicular, and at a 45-degree angle to the flow. Effects of injector orifice diameters (0.8mm, 1mm, 1.2mm) on atomization and penetration length distribution are investigated. SolidWorks is used for design, and Ansys with a coupled implicit second-order upwind solver analyzes the Reynolds-averaged Navier-Stokes equation. Eddy dissipation handles combustion. Hydrogen and ethanol are modeled and injected, reacting with atmospheric oxygen.

A method is proposed for estimating the stress field near a semi constrained inclusion. The volume of the stress-free misfit inclusion was separated into totally restricted and only loosely constrained parts. To achieve this, a fictional notch mirroring the inclusion matrices was introduced, and misfit displacement was applied. An elastic finite element analysis under a planar stress condition was conducted to identify the stress field surrounding a hydride blister in the Cr-3.5Ni pressure tube alloy. By assuming the orientation of hydride platelets in the matrix, the precision of computations was demonstrated. Our findings unveil distinct characteristics in the hydride platelet's axial dimension and orientation, highlighting their resistance to self-reorientation, even in the presence of radial hydrides. The consistent size and spacing of hydride platelets around the blister, despite nearby radial hydrides, emphasize the alloy's unique behavior.

An ECU is at the heart of control of any modern IC engines which has several functions to be monitored and controlled. Among the controlled parameters are fuel supply and ignition which are dependent on few real time measured parameters such as crankshaft position, mass air flow. The output of the ECU performs an action on the engine by controlling amount of power to actuators precisely. ECU are designed to stand the adverse conditions of operation to which a vehicle is typically exposed to, but in few cases, ECU fail due to faulty wiring and over voltage. The prime solution used is to replace the faulty ECU by new one. But this solution has limitations that the replacement costs are high. As an alternative for repairing ECUs, our project focuses on creating an ECU bench test tool for real time ECU testing and validate the working of ECU. A Technician is need of an ECU bench simulation tool that can generate signals similar to CKP, TPS, O2, MAP, IAT and CLT sensors.

Over the years the vehicle population has drastically grown which increases the number of road accidents. The accident severity caused fatality and disability being reduced by introducing energy absorption materials (Crash tube). Over the years, researchers have used aluminium, magnesium, and titanium crash tubes to enhance the energy absorption characteristics during different crash scenarios. However crash tube will possess sufficient rigidity to absorb the impact force during collision but it is still challenging to identify the right material. At the same time, this paper aims to examine the energy absorption characteristics of Aluminium-Magnesium hybrid material (Al-Mg 5456) crash tube designs. Three designs were considered square, cylindrical, and hexagonal designs along with different notch designs to minimize the weight percentage of tubes. The LSDYNA results the oval notches performed better in energy absorption when compared to other designs.

A Single Cylinder Medium Speed diesel engine research facility has been developed for investigating areas of current technical concern to the rail, marine and stationary power industries. The design and operation of this Single Cylinder Research Engine (SCRE) is described. The facility is centered around a Bombardier model 251-plus 11.0 L engine which is representative of four stroke multi-cylinder railroad, marine and small stationary powerplant engines. All engine support systems (air, cooling water, fuel oil and lubricating oil pumps) operate independent of the engine enabling a wide range of adjustments in flow, pressure and temperature. Current program areas for which this system is used include alternative fuels evaluation, combustion analyses, fuel injection system development, component wear and durability studies, engine friction analyses, lubricant testing and emissions evaluations.

The interactive use of a vehicle-trailer handling model is presented. The model is a high resolution simulation of general vehicle (passenger cars to multitrailer) handling, braking, and vehicle-barrier interaction which is exercised interactively with a “human driver” over a realistic road (pavement, shoulder, median strip, etc.). At all times during the simulation, the operator can simulate the use of any normally available controls, i.e., steering, braking, throttle. The model has been developed and/or used over a number of years under various contracts with NHTSA, FHWA, DOD, and a number of industrial companies. Included in the paper are the results of a simulation run involving driver performance, vehicle parameters, and roadway conditions.

Although methane number is widely used to predict knocking occurrence and its intensity, it does not determine a fuel composition uniquely, that means, the knocking intensity by the different composition fuel must show difference even if the same methane number fuels are employed. To establish a novel index, the knocking intensity and the autoignitive propagation velocity, as consequence of spontaneous ignition process, are investigated both experimentally and numerically by using the different composition gaseous fuels with same methane number. Methane/ethane/air and methane/n-butane/air mixtures with the same methane number of 70 and the equivalence ratio of 0.5 were employed. They are rapidly compressed and ignited spontaneously by a Rapid Compression Machine. Ignition delay times, autoignitive propagation velocities, and knocking intensity were measured by acquired pressure histories and high-speed imaging.

The authors developed a gasoline engine that combined direct injection and port fuel injection in order to improve fuel economy for motorcycles. Compared to passenger car engines, motorcycle engines generally have smaller displacement and operate at higher engine speed, so the bore and stroke are generally smaller than those of passenger cars. Therefore, the direct injection spray characteristics optimized for small bore and stroke were selected to reduce fuel adhesion to various parts of the combustion chamber wall. In addition, this engine employed the high tumble intake port that can both strengthen turbulence intensity and suppress the decrease in volumetric efficiency to a lower level. Also, stratification of air-fuel mixture and split injection were employed for reducing catalyst warm-up time and soot. The results showed that excellent fuel economy was achieved without sacrificing engine output performance while meeting emissions regulations.