Title: Analysis of an extremely fast valve opening camless system to improve transient performance in a turbocharged high speed direct injection diesel engine

Authors: J. Benajes, J.R. Serrano, V. Dolz, R. Novella

Addresses: CMT-Motores Termicos, Universidad Politecnica de Valencia, Camino de Vera s/n, Valencia 46022, Spain. ' CMT-Motores Termicos, Universidad Politecnica de Valencia, Camino de Vera s/n, Valencia 46022, Spain. ' CMT-Motores Termicos, Universidad Politecnica de Valencia, Camino de Vera s/n, Valencia 46022, Spain. ' CMT-Motores Termicos, Universidad Politecnica de Valencia, Camino de Vera s/n, Valencia 46022, Spain

Abstract: This article describes a theoretical study on the performance optimisation of a high speed direct injection turbocharged diesel engine equipped with an electro-hydraulic variable valve actuation |camless| system. This system provides extremely fast valve opening and closing slopes. Thus, its potential for recovering part of the energy lost in the valves by reducing gas flow sonic conditions in the valve throat has been investigated. This study has been mainly focused on the analysis of engine performance during a load transient evolution, but the full load steady state attained at the end of the load transient has been also discussed. The results of this investigation have confirmed important improvements in engine performance during the load transient owing to less energy being lost across the valves, which directly results in more energy being available in the turbine. This benefit has also been observed at full load steady state conditions.

Keywords: diesel engines; energy management; engine transient performance; turbocharging; VVA; variable valve actuation; valve opening camless systems; turbocharged diesel engines; high speed diesel engines; direct injection engines; load transient.

DOI: 10.1504/IJVD.2009.024247

International Journal of Vehicle Design, 2009 Vol.49 No.1/2/3, pp.192 - 213

Published online: 30 Mar 2009 *

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