Top Land Crevice and Piston Deflection Effedts on Combustion in a High Speed Rotary Valve Engine

Document Number: 2008-01-3005

Date Published: December 2008

Author(s):
Harry Watson - Univ of Melbourne
Alberto Boretti - Univ. of Melbourne

Abstract:
The Bishop Rotary Valve (BRV) has the opportunity for greater breathing capacity than conventional poppet valve engines. However the combustion chamber shape is different from conventional engine with no opportunity for a central spark plug. This paper reports the development of a combustion analysis and design model using KIVA-3V code to locate the ignition centers and to perform sensitivity analysis to several design variables. Central to the use of the model was the tuning of the laminar Arrhenius model constants to match the experimental pressure data over the speed range 13000-20000 rpm. Piston ring crevices lands and valve crevices is shown to be an important development area and connecting rod piston stretch has also been accommodated in the modelling. For the proposed comparison, a conventional 4-valve-per-cylinder poppet valve engine of nearly equal IMEP has been simulated with GT-POWER. The effects of crevices and piston assembly elasticity are shown to be more important in the rotary valve engine.

File Size: 1389K
Product Status: In Stock

See other papers presented at Motorsports Engineering Conference & Exposition, December 2008, Concord, NC, USA, Session: Advanced Combustion

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