The evolution of the Differential Compound Engine is described, from its initial conception, through experimental testing to possible future developments. The construction of the experimental apparatus is detailed, together with the development of this apparatus as experience gained was fed back as design improvements. The problem of predicting the performance off design of systems such as the differential compound engine is examined, and a simple one-dimensional analysis chosen as the most suitable theoretical treatment. The development of this treatment into a reasonably general computerised analysis is described. As part of the analysis mathematical models of Rootes TS 3 and Perkins 6.354 engines, and of several compressors and turbines have been developed. The useful one-dimensional analysis of radial inflow turbines written for this modelling is given in detail and compared with experimental data. Systems modelled have been the differential compound engine, turbo charged engine, and systems involving combustion chambers. Agreement between measured and predicted performance is found to be dependent on the degree of accuracy with which losses are modelled. Possible models for some losses are given. With the aid of the computerised analysis, the possible future development of the differential scheme is considered, and conclusions reached as to the most rewarding direction for future effort.
|Date of Award||1971|