Design and Development of Intake Ports for 2-Valve & 4-Valve Configurations for Heavy Duty Off-Highway Diesel Engine

Future emission limits for off-highway application engines need advanced power train solutions to meet stringent emissions legislation, whilst meeting customer requirements and minimizing engineering costs. Development of diesel engines for off-highway application for different power segments need different intake port design solutions to optimise in-cylinder flow structure for efficient combustion. With adaptation of low pressure mechanical fuel injection system, intake port development becomes an important stage for reduction of emission formation at the source and improvement in fuel economy.

In this paper, intake port design and development process is elaborated for two different power ratings of 75 hp and 120 hp of off-highway engine. 2-valve and 4-valve configurations are deployed for the same cylinder bore size. Considering the legislative emission limits for these two power segments of engines, intake port are designed for target swirl and flow performance within the same constraints of cylinder head bolting pattern and valve train actuation mechanism. Intake port designs are experimentally evaluated on steady state flow test rig using AVL paddle wheel method for swirl and flow coefficient performance. A detail numerical analysis is carried out using AVL FIRE CFD simulation software to study developed flow structure and interactions. An efficient design of 4-valve intake port is carried out with the aid of CFD analysis.