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A new internal combustion engine is proposed. This engine is one example of gas generator engines, configured according to a newly proposed cycle principle. Turbocharging with intercooling is employed to reduce the energy loss of engine exhaust. A reciprocating piston-gasifier is used to further boost the pressure and to raise the turbine inlet temperature near its material limit. To study the feasibility of the proposed engine, a piston-gasifier is designed to consist of manifolds and pairs of cylinders with different bores. To simulate the operations of the piston-gasifier, a numerical model is developed. The manifolds and cylinders are treated as open systems and combustion is described as a one-zone heat release process. Subprocesses are described in sufficient detail. The operating characteristics of the piston-gasifier are predicted and analyzes over a broad range of operating parameters.

In the first part of this two-part article, a piston-gasifier is designed, and its quasi-steady operating characteristics are predicted by a numerical model. The objective of this second part of article is to study the operating characteristics of the whole engine system. Intercoolers are designed, and their effectivenesses are solved by a combination of analytical solution and empirical correlations. The turbocharging compressors and turbine are described by steady state performance maps. The power turbine is described by the modified Stodola Ellipse with efficiency assumed constant. The numerical model matches the operations of all components to predict the performance of whole engine system. Utilizing the operating characteristics of the piston-gasifier, the cycle analysis of the whole engine system indicates that there is an optimum intake pressure of the piston-gasifier for each set of crankshaft speed and piston-gasifier exhaust temperature.

This paper makes the case for the gas generator engine - a type of compounded engines - as a potential future automotive engine. The existing gas generator engines are characterized by their mediocre performance and fuel economy. The case for the new gas generator engine is based on a proposed cycle principle, which achieves simultaneous improvements in thermal efficiency and power output/weight ratio. This very attractive engineering solution may transform the mediocre existing engines into new engines of exceptional promise, which merit serious consideration.