An MHD generator as a commercially viable electrical source could offer a very efficient utilization of fossil fuel resources because of its high overall generation efficiencies. Investigations in recent years have confirmed this expectation, but there are many problems which are not yet resolved in regard to the gas dynamic characteristics of the MHD generators. The purpose of the present paper is to report the results of experimental studies of the steady supersonic flow in a Faraday-type MHD generator. The plasma for an MHD generator was produced using a shock tunnel. The color schlieren method was employed to observe the supersonic flow in a channel. The experimental results show clearly oblique shock waves and Prandtl-Meyer fans from electrode edges, and it is shown that, with an increase in the Lorentz force, the flow Mach number in a channel decreases and the shock changes its shape from an X type to a λ one.

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The paper describes small scale bio-mass electric power plant. Saw dust is used for the fuel. Gas reactor is developed and improved to increase the gasifying efficiency. The engine exhaust heat is exchanged to hot water and hot air. The hot air is used to dry the lumber. As the result, total efficiency of this electric power-heat co-generation system is eminently improved.

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The interaction and breakup process of 1.50 mm diameter ethyl alcohol droplets and 5.14 mm diameter water bubbles with planar shock waves were observed by using a double exposure holographic interferometer. It is shown that the holographic interferogram can eliminate the light scattering by the mist which was produced over the breaking up of the droplet and its wake, and made their structures obscure. It is found that the diameter of the breaking up droplet has been overestimated by up to 35% by comparing the droplet diameter determined from a holographic interferogram and a shadowgraph from which the holographic interferogram was reconstructed.

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An evaluation procedure of holographic interferograms is described to determine the three-dimensional temperature distribution of a thermally developing convection flow in the direction of the object beam. The thermal boundary layer developing along a constant-temperature wall is divided into equidistant infinitesimal sublayers where the refraction index is assumed to be constant. This leads that their refraction index values can then be expressed as a step function, but the measured fringe orders should be compensated by four additional fringe order shifts. The procedure is verified to be reasonable from an experiment on the forced and free combined convection in the entrance region of a horizontal rectangular duct with a constant-wall temperature.

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Some cholesteric liquid crystals change their color according to temperature and are used to show temperature distribution on a surface qualitatively. The present study developed a quantitative method by which temperature distribution can be displayed just like an infra-red thremo-camera. At first, the theoretical ground is presented. The spectral properties of liquid crystal and optical filters are determined. Calibration methods are described and the accuracy of this method is evaluated as 0.2°C, and the order of resolution is 0.01°C. For application, temperature distributions on heated surfaces attached by a cylinder are measured in detail.

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In this study, a test of exhaust gas noise reduction is reported through the application of a heat-resistant epoxide resin, in place of a steel motorcycle muffler of a gas engine exhaust system. The findings show that this resin muffler results in a noise reduction without decreasing the engine efficiency, even in a restricted space. The experiments were conducted using the same shape for the steel and resin mufflers which were set at the outlet of a 250 ml engine exhaust system. The noise level of the exhaust gas after being introduced into the shielding compartment was measured by a standard noise-meter and FFT analyzer for the comparison of noise reduction effect.

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In this study, the exhaust gas noise reduction is reported through the application of a heat resistant epoxide resin, in place of a 1.5 L 4-cycle gas engine steel muffler. The findings show that this resin muffler of the same shape as a steel muffler results in noise reduction without decreasing the engine efficiency, even in a restricted space. Being measured by a standard noisemeter and FFT analyzer, the noise reduction effect was analyzed to have a relationship with the temperature of the muffler, and with the frequency.

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The bulk velocity and turbulence of air swirl flow in the dish type combustion chamber of a motored engine were measured by an LDA. The LDA was modified with optical finers for easy operation and was improved to form a smaller measuring space 0.29 mm in length. The engine was operated at a speed of 1 000 rpm. The gas velocity at a mid section of the combustion chamber was analyzed by the stationary time average method. The radial distribution of mean swirl flow and turbulence characteristics such as turbulence intensity (u'), integral time and spacial scale (L_t, L) and micro time and spatial acale (λ_t, λ) were obtained, and time depending properties of such flow data were investigated. It has been revealed that the mean swirl velocity and swirl ratio almost agree with those of previous reports, but u' is higher and scales of turblence are lower than the data given by the hot-wire anemometer.

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The velocity and turbulence in two-dimensional wedge type engine combustion chambers are measured by a laser Doppler anemometer (LDA) with an optical fiber transmitting system under motored and firing conditions. The engine is operated at a speed of 2 500 rpm with propane-air mixtures changing the combustion chamber setting direction to the cylinder, here named normal "N" and reverse "R" combustion chambers. The preliminary experiment indicates that the flame propagating velocity near the slant ceiling and the indicated mean effective pressure are of a higher level at the R chamber than at the N chamber. The mean velocity U^^-, fluctuation intensity u' and integral time scale of turbulent L_t in both chambers are derived through the stationary time averaged analysis of the measured velocities, and each is compared between both chambers. The results have showed that the flow patterns in both chambers are different and the mean value of the U^^- of the R chamber at the spark timing is large than the other by about 70%. However there is little difference at u' and L_t in both chambers.

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In the preceding report was shown the effectiveness of the new control scheme in which wheel speed is detected to suppress the power-train's torsional vibration called 'surge'. However, the time lag compensation method used therewith was a little too poor to confirm its general efficiency. In the present work was contrived a new lag compensation method in which the shaft torque is taken into consideration, and it is shown that the shaft torque could be indirectly detected through an observer based on the state equation of the engine-vehicle system. An analog circuit observer makes the shaft torque measurement quite successful. Finally is proposed a new speed-control system which is particular to the control of torsional vibration and not that of rotation speed. The new system is expected to improve the driveability of a diesel vehicle since the driver's command directly corresponds to the engine output torque. Engine test demonstrated the validity of the new lag compensation, as well as the effectiveness of the new system.

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The direct-injection stratified-charge engine is considered to be a promising alternative to convectional spark-ignition engines. It has the favourable features of high thermal efficiency, low carbon monoxide and nitric oxide emission levels as well as multifuel capability. It has, however, the unfavourable feature of a high unburned hydrocarbon emission level, especially during light-load operations. In order to conquer this problem, the locally near-premixed direct-injection stratified-charge combustion system was examined in this study, using a pancake type constant volume bomb. A mixing promoting projection was attached to he inner circumference of the bomb to make locally near-premixed mixture. Experimental analyses were made on combustion pressure histories and on stratification processes. Some improvements on the maximum combustion pressure, combustion duration and unburned hydrocarbon emission level were obtained by this new system compared to the basic direct-injection stratified-charge combustion.

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The present study deals with the theoretical analysis required for the design of a vaneless nozzle for an axial turbine. This vaneless has a turbine scroll in a vertical position to the turbine rotor axis. The working fluid flows from the inlet to the scroll perpendicular to the rotor axis, thus resulting in having an angular momentum to the axis. The flow from the scroll expands in an inducer section, making a swirl flow under the condition of constant angular momentum. Then the flow is turned to the direction of the turbine axis and goes to the turbine blades. The paper makes clear the existence of the flow which is satisfied with the condition that the outlet angle is constant and the circulation is constant respectively in the direction of the radius at the outlet of the vaneless nozzle.

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Coolant was injected from three holes on the center line of a pressure surface of a gas turbine blade. The density ratio and mass flow ratio were changed in the ranges of 1∼3 and 0.1∼1.5 respectively. The film cooling effectiveness on the center line was mainly governed by the momentum ratio, and the optimum momentum ratio was about 0.01. The empirical formula for the film cooling effectiveness on the center line was decided as the functions of the dimensionless streamwise distance from the injection hole and the momentum ratio. The maximum and mean errors of this formula were 26.8% and 9.2% respectively. The normalized dimensionless spanwise distribution of the film principle of superposition, one can predict the distribution of full coverage film cooling effectiveness on the pressure surface under the optimum condition.

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