The Technical and Commercial Feasability of a High Speed Diesel Engine of High Specific Output

Abstract

The objective of this work is to evaluate the new product potential of high specific output, high-speed diesel engines. The research, which was undertaken on the Stafford site of Dorman Diesels Limited, considers technical and commercial aspects of the problem. As such, the project is an example of applied, rather than pure research, seeking to elucidate a multi-dimensional problem of direct interest to the sponsor. Several methods have been successfully used to increase specific output. The design principle employed for this study was to increase the maximum brake mean effective pressure (bmep) by using a high level of turbocharge. Mechanical loads were contained by lowering the compression ratio. Typically, the most highly rated, commercially available engines operate at bmep's of 14 to 16 bar. This project assesses the feasibility of a current Dorman engine operating at a bmep of 21 bar at fixed speed. A review of literature was followed by a design study which made use of computer-based engine performance and heat conduction models new to the company. This led to the specification of a research engine which was constructed and operated successfully in the sponsor's development facility. The technical study was used to form a rudimentary product profile as the basis of a limited assessment of market potential. Consideration was given to the compatibility of the concept with current engine applications, and the suitability of corporate skills and other resources. The broad product characteristics were compared with the needs of identified market segments. The concept was found to have only limited potential compared with current engine designs, which find almost universal usage. The project has increased the company's experience and database, thus allowing more rational decision-making on the future of high output engines in the Dorman product range