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An analytical method for determining engine torque harmonics is presented. The approach employs an engine cycle simulation model to calculate instantaneous cylinder pressure for each operating condition based on engine characteristics that can be determined experimentally and/or analytically. Cylinder pressure is converted to instantaneous torque from which harmonics are determined using an FFT algorithm. A description of the cycle simulation model, including required data, is presented. The method is validated by presenting correlation results at a number of operating conditions (i.e. engine speeds and loads) comparing analytical versus test driveline torque harmonics. Finally, limitations in the method as well as possible extensions to the method are discussed.

Two combustion systems were developed and optimized for an engine for a power cylinder of 0.8-0.9L/cylinder. The first design was a re-entrant bowl concept which was based on the combustion system of a smaller engine with roughly 0.5L/cylinder. The second design was a chamfered bowl concept, a variant of a reentrant bowl that deliberately splits fuel between the bowl and the squish region. For each combustion system concept, nozzle tip protrusion, swirl, and nozzle configuration (number of holes, nozzle flow, and spray angle) were optimized. Several similarities between combustion system concepts were noted, including the optimal swirl and number of holes. The resulting optimums for each concept were compared. The chamfered combustion system was found to have better part-load emissions and fuel consumption tradeoffs. Full load performance was similar at low speed between the two combustion systems, but the reentrant combustion system had advantages at high engine speed and load.

The technique of evaporating fuel by localized heating before entering the intake manifold is evaluated as a means of improving A/F ratio control. Techniques currently in use are briefly discussed, and attempts to analyze fuel evaporation in S.I. engines are reviewed. A test fixture which includes all the essential features of production feasible hardware is used to develop a basis of understanding for the evaporation process. Tests are conducted on a flow bench using water as “fuel”, and on an engine using isooctane and gasoline. A heat-mass transfer analogy is described and used to predict evaporation rates for water and isooctane. Predicted and measured rates are compared for both bench and engine tests. Engine tests with gasoline show the ability of the test configuration to evaporate all part throttle fuel flow before it enters the intake manifold.

Natural luminosity (NL) and chemiluminescence (CL) imaging diagnostics are employed to investigate fuel-property effects on mixing-controlled combustion, using select research fuels-a #2 ultra-low sulfur emissions-certification diesel fuel (CF) and four of the Fuels for Advanced Combustion Engines (FACE) diesel fuels (F1, F2, F6, and F8)-that varied in cetane number (CN), distillation characteristics, and aromatic content. The experiments were performed in a single-cylinder heavy-duty optical compression-ignition (CI) engine at two injection pressures, three dilution levels, and constant start-of-combustion timing. If the experimental results are analyzed only in the context of the FACE fuel design parameters, CN had the largest effect on emissions and efficiency.

In this paper, we present the results of a series of experiments to determine the exhaust particulate size distributions from a number of diesel, gasoline and compressed natural gas (CNG) fuelled vehicles. The results show that all three types of vehicle produce significant populations of particulates under certain operating conditions. Particulates produced by gasoline and CNG engines tend to be smaller than for diesel engines. At low loads, there is a significant particulate distribution for diesel engines but much lower particulate numbers for both gasoline and CNG vehicles. Under these conditions, the gasoline particulate distribution has little structure but the CNG distribution is clearly bimodal. At higher loads, the number of particulates produced by diesel vehicles increases by an order of magnitude from idle and both the CNG and gasoline distributions are comparable in peak height. The diesel vehicle produces a much larger particulate volume than gasoline or CNG.

The design requirements for the frame as a load carrying member are discussed in relationship to a highway truck and its basic vehicle package. The theoretical and experimental procedures are given in detail to demonstrate the techniques for frame design. The features of a method to laboratory test a frame with correlation to service miles is discussed.

A method for the measurement of nitric oxide (NO) in photochemical smog research was developed using the chemiluminescence from the rapid reaction between ozone (O3) and NO. An instrument based on this method has been constructed; it is applicable to a number of automotive problems. This NO detector has been tested extensively in both laboratory and dynamometer experiments, and has been shown to have several outstanding features: detection sensitivity of 0.01-5000 ppm, selective detection for NO, continuous monitoring with fast response time, and good stability and ease of operation. Examples of results obtained in turbine experiments and in vehicle exhaust analysis are presented.

Using instrumentation designed for the ultrasonic measurement of thickness, a technique has been devised for measuring the isotropic elastic constants of small samples, i. e., samples 1 mm in thickness and a minimum of 5 mm in other dimensions. Young's modulus, the shear modulus and Poisson's ratio are calculated from measurements of density and ultrasonic shear and longitudinal wave velocities. Samples of valve train materials, including chill cast iron, low alloy steel, tool steel, stainless steel, a nickel-base superalloy, and a powder metal alloy were machined from components and analyzed. The magnitude of the measured values of the elastic constants are reasonable when compared with published values. The measurement error on all the constants is estimated to be less than 1%. Moduli determined by this method can be used in finite element analyses to improve designs.

The study presented in this paper is concerned with the application of a finite element based technique to deal with crankshaft-crankcase interaction. A finite element model of the crankshaft and the crankcase was developed and appropriately reduced. This model was used for a crankshaft optimization, strategy to analyse related effects on the NVH performance with focus on main bearing acceleration. The crankshaft and the cylinder block were modelled using beam and shell elements with structural and dynamic properties correlated up to 1600 Hz. The interaction between crankshaft and the cylinder block was represented by using non-linear properties. Applying this model, the dynamic crankshaft and engine block behaviour and repercussion on NVH performance was analysed by investigating main bearing acceleration.

The intent of this paper is to summarize the work of the V8 power plant intake manifold radiated noise study. In a particular V8 engine application, customer satisfaction feedback provided observations of existing unpleasant noise at the driver's ear. A comprehensive analysis of customer data indicated that a range from 500 to 800 Hz suggests a potential improvement in noise reduction at the driver's ear. In this study the noise source was determined using various accelerometers located throughout the valley of the engine and intake manifold. The overall surface velocity of the engine valley was ranked with respect to the overall surface velocity of the intake manifold. An intensity mapping technique was also used to determine the major component noise contribution. In order to validate the experimental findings, a series of analysis was also conducted. The analysis model included not only the plastic intake manifold, but also the whole powertrain.

This paper discusses in detail three applications of photoelasticity to engine component design and failure analysis. This stress analysis technique provides whole field stress distribution and can also be used to optimize a design by obtaining even stress distribution. The applications discussed cover several aspects of photoelasticity such as two and three dimensional model analysis, stress freezing, thermal and mechanical loading simulation. These are some of the many investigations conducted by the authors and can be used as a guide to many other applications. The results of the analysis have been verified during endurance testing, but are not discussed in this paper.

This case study presents a new automated production noise test for power steering pumps. The test included adaptive noise cancellation, and a neural network implementation. The result mapped the pump acceleration signature into an objective repeatable noise metric. The test algorithm was a distributed DSP architecture designed for real-time measurement and decision processing. It was implemented with no increase in test cycle time. It accomplished the correlation of in-vehicle power steering pump noise to it's vibration characteristics, and retrofitting of accelerometers in place of microphones for acceptance testing.

Automatic headway control is an evolutionary step towards an automatic vehicle guidance and control system. This system expands the capability of the currently available production option-speed control. This paper describes the system from a theoretical and hardware viewpoint, with emphasis on the control logic. The electronic and electromechanical hardware design based on the theory presented is fully described. The limitations and advantages of the system are explained, based on test results from actual trial runs on an implemented vehicle. Capacity and safety benefits are made somewhat tangible by direct comparison with test results obtained on a roadway similar to that for which this system is recommended, under test conditions directly analogous to the operating characteristics of the automatic headway control system.

Recently an increase in interest has occurred in automotive powerplant mounting. Evidence of this growth is the increase in the number of publications on the topic. The majority of this renewed interest has come from predicting and understanding the response of hydraulic engine mounts and the application of optimization techniques to the problem of powertrain vibration isolation, and occasionally to the combination of these two topics. However, it appears that these analytical techniques have been sufficiently developed and correlated to actual powertrain systems to have found widespread use by the automotive manufacturers. Subject to timing and packaging constraints, the more traditional mounting system design strategies are typically utilized. These strategies include natural frequency placement, torque axis mounting and elastic axis mounting. This paper presents a comprehensive review of these three strategies including a discussion of the assumptions associated with each method.

This paper describes the development and key features of a bar code based, computerized gas cylinder inventory and record keeping system developed by Ford Motor Company's Gas Standards Laboratory. The paper will demonstrate how bar code technology is being utilized to track compressed gas cylinders efficiently and accurately. It will also describe the link between bar code technology and a data base that was developed using a fourth generation computer language. The implementation of this bar code/data base system has significantly increased data accessibility, improved data quality, reduced training time and increased the efficiency and flexibility of the data reporting process.

The exhaust blowdown pulse from each cylinder of a multi-cylinder engine propagates through the exhaust manifold and can affect the in-cylinder pressure of other cylinders which have open exhaust valves. Depending on the firing interval between cylinders connected to the same exhaust manifold, this blowdown interference can affect the exhaust stroke pumping work and the exhaust pressure during overlap, which in turn affects the residual fraction in those cylinders. These blowdown interference effects are much greater for a turbocharged engine than for one which is naturally aspirated because the volume of the exhaust manifolds is minimized to improve turbocharger transient response and because the turbines restrict the flow out of the manifolds. The uneven firing order (intervals of 90°-180°-270°-180°) on each bank of a 90° V8 engine causes the blowdown interference effects to vary dramatically between cylinders.

In this paper, we compare controllers for the electronic throttle and variable geometry turbocharger in boosted stoichiometric gasoline direct injection engines. The control objectives are fast response and small overshoot of the intake manifold pressure. The problem is treated within the multi-objective optimization framework, applied to a simulation model of the engine. Pareto optimal fronts are constructed for each of the controllers and compared to each other. The best controller is thereby identified and further options to improve its response via preview-based control are discussed.

Naturally aspirated Homogeneous Charge Compression Ignition (HCCI) operational window is very limited due to inherent issues with combustion harshness. Load range can be extended for HCCI operation using a combination of intake boosting and cooled EGR. Significant range extension, up to 8bar NMEP at 1000RPM, was shown to be possible using these approaches in a single cylinder engine running residual trapping HCCI with 91RON fuel with a 12:1 compression ratio. Experimental results over the feasible speed / load range are presented in this paper for a negative valve overlap HCCI engine. Fuel efficiency advantage of HCCI was found to be around 15% at 2.62bar / 1500RPM over a comparable SI engine operating at the same compression ratio, and the benefit was reduced to about 5% (best scenario) as the load increased to 5bar at the same speed.

This paper presents the design and operation of a new stepped bore master cylinder (fast-fill) which also integrates the rear brake proportioning valves and brake failure warning device in one major assembly. This design optimizes weight, performance and package together with several unique design features. It incorporates a combination of a plastic reservoir, permanent mold aluminum body, steel pistons, and minaturized steel proportioning valves resulting in a significant weight and cost reduction versus equivalent hydraulic actuation systems.

All automotive brake linings have mechanical strength and thermal expansion properties which vary with orientation. This paper describes laboratory equipment and test procedures which characterize lining strength and expansion behavior, using small specimens. A benchtop testing device is introduced which can be used to perform shear and tensile tests on lining samples and singly-riveted lining assemblies. Results are presented for a representative group of production and experimental linings. Applications are discussed.