Measurement of Intake Valve/Cylinder Boundary Flows Using a Multiple Orientation Hot-Wire Technique

Abstract

A new measurement method is utilized to determine velocity distributions on the intake-valve/cylinder boundary for different induction system designs. The velocity information is being used to calculate the angular momentum flux and to define local discharge coefficients around the valve periphery. The contribution of local flow direction (effective area) and local flow speed (velocity losses) to the global discharge coefficients is examined. The dependence of the discharge coefficient on the flow direction and mean velocity magnitude provides useful diagnostic data to relate intake port geometry and flow performance. The measurement technique is also described in detail. The directional response of a single hot-wire anemometer is utilized along with sequential sampling of the signal as the probe shaft is rotated through 360 deg. Within the range of velocity and flow direction required, the velocity magnitude and direction can be determined to within 2 percent and 2 deg, respectively.