TKE Distribution According to the Intake Valve Angle in Steady Flow of the Pent-Roof SI Engine

This paper is for the investigation on the turbulence kinetic energy distribution according to the design parameters of the intake system. The design parameter to be discussed is the intake valve angle. For this purpose, particle image velocimetry was introduced into the steady flow bench, in which four engine heads with 11, 16, 21 and 26 ° valve angles were evaluated changing valve lift. The experiment was conducted at 1.75 B evaluation position. The effect of valve angles and lift was analyzed by the planar flow characteristics of in-cylinder flow and the turbulence kinetic energy variation along the radial direction. 11, 16, and 21 ° have high turbulence kinetic energy near the cylinder wall with the highest flow velocity, and the turbulence kinetic energy around the swirl center is relatively low, indicating the same qualitative characteristics. 26 ° tends to be differentiated from other valve angles, and spatially very complex and fluctuating flow occurred. Complex turbulence kinetic energy distribution pattern appears at all valve angles, while the average turbulence kinetic energy shows a parabolic form as the valve lift increases because of the influence of the flow entry direction by the valve lift.