Characterization of Shrouded Intake Valve in terms of Mean Flow Coefficient and Swirl Ratio

摘要

In recent time due to diminishing fossil fuels and deteriorating environmental conditions, manufacturers of spark ignition engines are giving maximum attention on the areas that include control of exhaust emissions and improvement of fuel economy. Use of swirling motion of air in the engine cylinder is one of the tested methods by which SI engine performance and emission is found to improve. Intake swirl motion can be generation within the working fluid of an SI engine by use of shrouded Intake valve. The greatest advantage of utilizing a shrouded intake valve is that it can be manufactured easily, and it permits to find the suitable level of swirl by rotating the valve about its axis. But, the main difficulty of using a shrouded intake valve is that it offers a greater restriction to the flow of incoming fluid. Thus, in this paper a steady flow test has been conducted to characterize shrouded intake valves with different shroud angle in terms of mean flow coefficient and swirl ratio and the results obtained from the test of the shrouded intake valves are compared with the results of the poppet intake valve. The obtained results show that the percentage increase in the swirl ratio and the percentage reduction in the mean flow coefficient of 60° shrouded intake valve is marginal compare to those of the poppet intake valve. However, in case of 120° shrouded intake valve it is average while, for the shrouded valve with 180° shroud it is found to be substantial.