Afterword

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INVESTIGATION OF A DIESEL GAS TURBINE

Thesis from Leicester Polytechnic Mr C Polonski and Messrs GEC Gas Turbines for loan of equipment Messrs Rolls Royce for the provision of equipmentThe turbocharging of automotive sized two-stroke engines presents a problem to the designer due to the large range of loads and speeds met in service. A mechanically driven blower is usually required to provide a positive pressure drop across the engine at all times, thus providing adequate air for scavenging. The aim of this investigation is to consider a. combination of the two-stroke cycle engine, turbocharger and auxiliary combustion chamber as a prime mover system with a satisfactory torque characteristic and control system. The auxiliary combustion chamber is used for independent control of the turbocharger. To this end various component combinations are described and assessed. Turbochargers of different builds and frame sizes havebeen examined to assess the effects of turbocharger matching. Computerised processing for data acquisition and control has been used. Theoretical work, progressing simultaneously with the experimental programme, has permitted the development of simple computer programs to predict system performance to a good degree of accuracy. The programs are detailed in the appendix. Experimental results have been presented graphically and compared with those predicted by the computer programs. The work has been extended, by computer techni~ues, to investigate the effects of charge cooling, heat exchange, and torque 'tailoring' by the control of engine boost levels. The Diesel Gas Turbine is shown to provide a feasible prime mover system. Significant improvements of power output and torque characteristic have been achieved within constraints of thermal and mechanical loading. The system incurs penalties in specific fuel consumption at low speeds but these are offset, to some extent, by improvements at high speed. The improved torque characteristics; would permit the use of a simpler transmission system, together with the removal of the scavenge blower.Leicestershire County Council and the Directorate of Leicester Polytechni