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In this study, we investigated the relationship of indicated mean effective pressure (IMEP) for a spark ignition engine under lean combustion with the cyclic variation of mass fraction burned by measuring the energy release from the spark plug, intensity of the light emmision from the flame and the cylinder pressure at the same time. In order to minimized an error in the initial and late combustion stages of the mass fraction burned to be obtained by cylinder pressure, spark plug energy and intensity of light emission were measured. As a result, it was found that there are three main couses of cyclic variation of IMEP. These consist of the burning speed during the initial stage of combustion, variation in the total mass fraction burned, and variation of the late burning during the late expantion stroke. Thus, we determined that there is a favorable interrelatonship between the IMEPs and the corrected mass fraction burned.

The droplet velocity, size and distributions of iso-octane fuel from single hole and twin jet air-assist injectors have been measured by phase Doppler velocimetry in the pent-roof for two cylinder head designs of firing four-valve engines running at 1500 rpm, together with the airflow during induction and compression. The use of the twin jet air-assist injector together with the introduction of a transfer-passage between the two intake ports of a Honda VTEC-E valve train arrangement resulted in reduction in ISNOx and COV-1mep of the order of half of those with the single hole injector design without a transfer passage. Droplets, for both heads and injectors, having passed the inlet valves, impinged directly onto the sleeve opposite to their entry without striking the exhaust valves and had velocities up to 30 m/s and Sauter mean diameters which varied from 20 to 50pm.

Hypersonic Transport Propulsion System Research (HYPR) Project was started in 1989 to develop the technologies for the propulsion system of a Mach 5 HST airplane, which could be environmentally acceptable and economically viable. The engine being studied is the combined cycle engine composed of a turbo engine which can operate from take-off to Mach 3 and a ramjet engine which can operate over Mach 2.5 to Mach 5. The variable cycle engine (VCE) concept is applied to the turbo engine to satisfy the requirements for low noise level at take-off and high specific thrust at high altitude and speed. The design and manufacture of demonstrator engines have been performed. The first turbo engine test and the first heated inlet test of the core engine was carried out successfully in December 1994 and March 1995 respectively. This paper describes the turbo engine design and those test results.

A combustion flame visualization system, for use as an engine diagnostics tool, was developed in order to evaluate combustion chamber shapes in the development stage of mass-produced spark ignition (S.I.) engines. The system consists of an image converter camera and a computer-aided image processing system. The system is capable of high speed photography (10,000 fps) at low intensity light (1,000 cd/m2), and of real-time display of the raw images of combustion flames. By using this system, flame structure estimated from the brightness level on a photograph and direction of flame propagation in a mass-produced 4-valve engine were measured. It was observed that the difference in the structure and the propagation of the flame in the cases of 4-valve and quasi-2-valve combustion chambers, which had the same in the pressure diagram, were detected. The quasi-2-valve configuration was adopted in order to improve swirl intensity.

This paper discusses the influence of variations in the vehicle deceleration curve on dummy injury criteria for a passive seat belt-restrained dummy using MVMA-2D crash victim simulation and sled tests for frontal crash analysis. The MVMA-2D simulation and sled tests verified that the vehicle deceleration curve exhibiting the higher Residual Deformation (RD) produces smaller dummy injury criteria. Also, using MVMA-2D simulation, the peak levels of the first and second waves were changed as parameters to ensure accurate evaluation of the influence of the deceleration curve on dummy injury criteria. Moreover, this paper also discusses Nissan's use of both occupant kinematic simulation and vehicle structural sisulation for frontal crash in the development of its vehicles.