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The testing system developed will decrease the time and the costs involved in evaluating cylinder head valve bridge designs. The test uses actual data generated from engine testing to recreate the valve bridge cracks that occur during dynamometer and vehicle testing. This paper focuses on the system description, the test development, design modifications, and the test results obtained. Testing shows that this method correctly separates valve bridge designs by test cycle life using statistical methods. It is a cost effective and timely alternative to dynamometer testing.

This paper introduces research work on 1-D model of Roots type supercharger with helical gears using 1-D simulation tool. Today, passenger car engine design follows approach of downsizing and the reduction of number of engine cylinders. Superchargers alone or their combination with turbochargers can fulfill low-end demands on engine torque for such engines. Moreover, low temperature combustion of lean mixture at low engine loads becomes popular (HCCI, PCCI) requiring high boost pressure of EGR/fresh air mixture at low exhaust gas temperature, which poses too high demands on turbocharger efficiency. The main objective of this paper is to describe Roots charger features and to amend Roots charger design.

A 10 KWe dual-mode space power system concept has been identified which is based on INEL's Small Externally-fueled Heat Pipe Thermionic Reactor (SEHPTR) concept. This power system will enhance user capabilities by providing reliable electric power and by providing two propulsion systems; electric power for an arc-jet electric propulsion system and direct thrust by heating hydrogen propellant inside the reactor. The low thrust electric thrusters allow efficient station keeping and long-term maneuvering. The direct thrust capability can provide tens of pounds of thrust at a specific impulse of around 730 seconds for maneuvers that must be performed more rapidly. The direct thrust allows the nuclear power system to move a payload from Low Earth Orbit (LEO) to Geosynchronous Earth Orbit (GEO) in less than one month using approximately half the propellant of a cryogenic chemical stage.

An advanced low heat rejection engine concept has successfully completed a 100 hour endurance test. The combustion chamber components were insulated with thermal barrier coatings. The engine components included a titanium piston, titanium headface plate, titanium cylinder liner insert, M2 steel valve guides and monolithic zirconia valve seat inserts. The tribological system was composed of a ceramic chrome oxide coated cylinder liner, chrome carbide coated piston rings and an advanced polyolester class lubricant. The top piston compression ring Included a novel design feature to provide self-cleaning of ring groove lubricant deposits to prevent ring face scuffing. The prototype test engine demonstrated 52 percent reduction in radiator heat rejection with reduced intake air aftercooling and strategic forced oil cooling.

Up to now, various compressor models for automotive air conditioners have been manufactured to answer the needs of car manufacturers for fuel economy and quietness. The 10PC20 compressor, developed for automotive air conditioners, is the world's first swash plate type compressor having a continuously variable displacement mechanism. The 10PC20 is aimed at realizing a large displacement compressor with a continuously variable displacement mechanism, which has not been achieved until today. To achieve this goal, the 10PC20 design is based on the swash plate type compressor, consisting of double-headed pistons, which is adaptable to a large displacement and has excellent rotating balance and durability. The 10PC20 changes its displacement continuously by changing the inclination of the swash plate (swash plate angle) continuously. (See photo. 1 and 2) The 10PC20 adopts two variable displacement principles.

The trend towards battery voltage vacuum fluorescent displays continues the technological advances in design and construction of VFD's, as they are applied to the automobile environment. With the ever increasing use of electronic displays for electronically tuned radios (ETR's), compact disc (CD) players, and other entertainment systems, advances in battery voltage displays and their associated drive circuitry have become a necessity. With the inherent advantages of low voltage operation and high information density, VFD's will continue to dominate the automobile audio markets. This paper will discuss battery voltage displays, the basic circuitry necessary to operate a vacuum fluorescent display, and comment on the “off the shelf” controller and driver circuitry available.

Transfer path analysis is a powerful tool to support the vehicle NVH development. On the one hand it is a fast method to gain an overview of the complex interplay in the vehicle noise generation process. On the other hand it can be used to identify critical noise paths and vehicle components responsible for specific noise phenomena. FEV has developed several tools, which are adapted to the considered noise phenomena: Powertrain induced interior noise and vibration is analyzed by VINS (Vehicle Interior Noise Simulation), which allows the deduction of improvement measures fast enough for application in the accelerated vehicle development process. Further on vehicle/powertrain combinations not realized in hardware can be evaluated by virtual installation of the powertrain in the vehicle, which is especially interesting in the context of engine downsizing from four to three or six to four cylinders.

Two-phase capillary loops are being extensively studied as heat collection and rejection systems for space applications as they appear to satisfy several requirements like low weight, low volume, temperature control under variable heat loads and/or heat sink, operation under on ground and micro gravity conditions, simplicity of mounting and heat transfer through tortuous paths. In 1998–2000 Alenia defined and Lavochkin Association developed the Deployable Radiator on the base of honeycomb panels, axial grooved heat pipes and Loop Heat Pipe. It was designed for on-ground testing.

Direct fuel injection is becoming mandatory in two-stroke S.I. engines, since it prevents one of the major problems of these engines, that is fuel loss from the exhaust port. Another important problem is combustion irregularity at light loads, due to excessive presence of residual gas in the charge, and can be solved by charge stratification. High-pressure liquid fuel injection is able to control the mixing process inside the cylinder for getting either stratified charge at partial loads or quasi-stoichiometric conditions, as it is required at full load. This paper shows the development of this solution for a small engine for moped and light scooter, using numeric and experimental tools. In order to obtain the best charge characteristics at every load and engine speed, different combustion chambers have been conceived and studied, examining the effects of combustion chamber geometry, together with injector position and injection timing

CHEVROLET has made its new air-suspension system easily interchangeable in production line assembly with standard full-coil suspension by adopting a 4-link-type rear suspension with short and long arms. A feature of the system is the mounting of the leveling valves within the air-spring assemblies. These valves correct riding height continually at a moderate rate, regardless of whether the springs are leveling or operating in ride motion. The system provides constant frequency ride—ride comfort remains the same whether the car is occupied by the driver alone or is fully loaded.

As part of the 1997 Propane Vehicle Challenge, a team of twelve UTEP students converted a 1996 Dodge Grand Caravan with a 3.3 L V6 engine to dedicated Liquefied Petroleum Gas (LPG) operation according to the 1997 Propane Vehicle Challenge (PVC) competition rules (16). The 1997 UTEP team developed an LPG liquid phase port fuel injection (LPP-FI) system for the minivan. The UTEP design strategy combines simplicity and sound engineering practices with the effective use of heat resistant materials to maintain the LPG in the liquid phase at temperatures encountered in the fuel delivery system. The team identified two options for fuel storage with in-tank fuel pumps. The competition vehicle incorporates a five-manifold eight inch diameter Sleegers Engineering LPG tank fitted with a Walbro LPTS in-tank pump system, providing a calculated range of 310 city miles and 438 highway miles.

Using a holistic 1D engine simulation approach for the modelling of full-transient engine operation, allows analyzing future engine concepts, including its exhaust gas aftertreatment technology, early in the development process. Thus, this approach enables the investigation of both important fields - the thermodynamic engine process and the aftertreatment system, together with their interaction in a single simulation environment. Regarding the aftertreatment system, the kinetic reaction behavior of state-of-the-art and advanced components, such as Diesel Oxidation Catalysts (DOC) or Selective Catalytic Reduction Soot Filters (SCRF), is being modelled. Furthermore, the authors present the use of the 1D engine and exhaust gas aftertreatment model on use cases of variable valve train (VVT) applications on passenger car (PC) diesel engines.

This paper deals with some recent advances in the field of 1D fluid dynamic modeling of unsteady reacting flows in complex s.i. engine pipe-systems, involving a catalytic converter. In particular, a numerical simulation code has been developed to allow the simulation of chemical reactions occurring in the catalyst, in order to predict the chemical specie concentration in the exhaust gas from the cylinder to the tailpipe outlet, passing through the catalytic converter. The composition of the exhaust gas, discharged by the cylinder and then flowing towards the converter, is calculated by means of a thermodynamic two-zone combustion model, including emission sub-models. The catalytic converter can be simulated by means of a 1D fluid dynamic and chemical approach, considering the laminar flow in each tiny channel of the substrate.

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.

Simulation has become an integral part in the design and development of an automotive air-conditioning (AC) system. Simulation is widely used for both system level and component level analyses and are carried out with one-dimensional (1D) and Computational Fluid Dynamics (CFD) tools. This paper describes a 1D approach to model refrigerant loop and vehicle cabin to simulate the soak and cool down analysis. Soak and cool down is one of the important tests that is carried out to test the performance of a heating, ventilation and air-conditioning (HVAC) system of a vehicle. Ability to simulate this cool down cycle is thus very useful. 1D modeling is done for the two-phase flow through the refrigerant loop and air flow across the heat exchangers and cabin with the commercial software AMESim. The model is able to predict refrigerant pressure and temperature inside the loop at different points in the cycle.

Advanced control techniques are widely used in different automotive applications including climate control. Significant costs associated with the development and calibration of such controllers can be reduced if these tasks are conducted in a virtual environment. Such a virtual environment can be developed by integrating the controller with the system model. Different scenarios can be then simulated to make sure functional objectives of the system are met. 1D models provide the necessary level of accuracy without imposing extra computational cost in such virtual environments. As such, they are perfect candidates for model, hardware or software-in-the loop validation benches for controls. Performance of a heating, ventilation and air-conditioning (HVAC) system can be controlled through the settings of the components like mode door, blend door, recirculation door, blower, and the compressor.

Fuel cells plays significant role in the automotive sector to substitute the fossil fuels and complement to electric vehicles. In the fuel cell vehicles fuel cell stack is major component. It is important to have a robust fuel cell model that can simulate the behaviour of the fuel cell stack under various operating conditions in order to study the functioning of a fuel cell and optimize its operating parameters and achieve the best efficiency in operation. The operating voltage of the fuel cell at different current densities depends upon thermodynamic parameters like temperature and pressure of the reactants as well factors like the state of humidification of the electrolyte membrane. A 1D model is developed to capture the variation in voltage at different current densities due to internal losses and changes to operating conditions like temperature and pressure.

The introduction of more stringent standards for engine emissions requires a steady development of exhaust gas aftertreatment in addition to an optimized cylinder combustion. The reduction of the cold start phase can help significantly to lower cycle emissions. With the goal of optimizing the overall emission performance this study presents a comprehensive simulation approach. A well established 1D gas dynamics and engine simulation model is extended by three key features. These are models for combustion and pollutant production in the cylinder, models for the pollutant conversion in a catalyst, and a general species transport model. This allows to consider an arbitrary number of chemical species and reactions in the entire system.

Most of current jet aircraft circulate fuel on the airframe to match heat loads with available heat sink. The demands for thermal management in wide range of air vehicle systems are growing rapidly along with the increased mission power, vehicle survivability, flight speeds, and so on. With improved aircraft performance and growth of heat load created by Aircraft Mounted Accessory Drive (AMAD) system and hydraulic system, effectively removing the large amount of heat load on the aircraft is gaining crucial importance. Fuel is becoming heat transfer fluid of choice for aircraft thermal management since it offers improved heat transfer characteristics and offers fewer system penalties than air. In the scope of this paper, an AMESim model is built which includes airframe fuel and hydraulic systems with AMAD gearbox of a jet trainer aircraft. The integrated model will be evaluated for thermal performance.