Systematic computer modelling of advanced engine transmission systems for heavy vehicles.

  • Fahim F.K. Alhimdani

Student thesis: Doctoral ThesisPhD


Part of this work deals with the differential compound engine, developed at Bath University. The engine is designed to provide an integrated engine-transmission system providing high unit output, combined with outstanding torque characteristics for traction application. Therefore, the engine will have a probable future use for earth-moving and heavy machineries, and possibly in the agricultural field. The computer modelling of this engine has been carried out, with a view to determining the conditions for optimum performance. This has involved the employment of the iteration methods already developed for earlier versions of the computer model, to obtain the balance between each pair of adjacent components of the system. In the course of the work, the computer program was completely redeveloped for the specific task of performance optimization. The other part of this thesis is concerned with the dynamic modelling of the turbocharged diesel engine-fluid coupling-planetary gearbox system. The investigation is related to a special type of heavy engine-transmission components, which is employed by the British Leyland Company. An extensive contribution has been made to the development of a dynamic model for the analysis of the Wilson 5-speed gearbox. This gearbox, with a fluid coupling, constitutes the basis of the transmission. The possibility of adding or refining constructing blocks for different components has been explored. Accordingly, a new method for linking the various sub-models was established by using the energy storage reservoir concept, which was considered as a basic tool for such integration procedures. Furthermore, a computer model was developed to increase the understanding of the dynamic behaviour of heavy vehicles. The objective was to provide a rational basic approach for the analysis of engine-transmission features, which could be utilized for these types of vehicles so that important variable, particularly the fuel economy which is based on engine operating conditions defined by the dynamics of vehicle motion, could be computed. While the work described is predominently theoretical, experimental work has nevertheless been conducted on both systems, using existing test rigs and instrumentation, and working in association with other research students.
Date of Award1977
Original languageEnglish
Awarding Institution
  • University of Bath

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