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The pulsating pipe flow with a diffuser was studied numerically and experimentally. Comparing the numerical results using a Random-Choice Method with those of experiments, a good agreement was found regarding pressure histories at each station along pipes, and in particular, as far as the locations of shock waves are concerned the agreement was excellent.

The pulsating flow in a duct with a junction was studied numerically using a Random-Choice Method and the experiments were carried out to check if this numerical simulation is valid or not. As a result, good agreement was found between the experiment and numerical calculation. Concerning the location of the shock wave the agreement was excellent. The Random-Choice Method may be applied to real reciprocating engines by coupling it to a multi-dimensional in-cylinder simulation.

The behavior of pressure waves in the exhaust and intake pipes of the internal combustion engine plays an important role in the increase and decrease of the flow rate through these pipes. Using the rotary valve of disc type the effect of the pressure wave on the flow rate through the pipes with junctions or nozzles was studied. It was found that the arrival time of the compression wave at the port of the valve was the important parameter in evaluating the increase and decrease in flow rate.

A numerical scheme known as the Random-Choice Method was applied to analyze the pulsating flow in a pipe with and without a nozzle. Good quantative agreement between shock locations obtained experimentally and numerically was found. Furthermore, the pressure histories of flow upstream of the nozzle show good quantitative agreement.

A study of “diesohol” - ethanol blended with diesel fuel - was made for both pre-chamber type and open-chamber type heavy duty diesel engines. Performance tests were conducted to evaluate changes in power, fuel consumption, smoke and exhaust emissions for diesel fuel and blends of 10% and 20% ethanol. The open-chamber type engine fueled by 20% diesohol was subjected to a 500 hour durability test. Oil deterioration, wear of parts etc. were measured and promising results were found.