Abstract
Investigation of heat transfer phenomena near the wall in the internal combustion engines contributes to improve the thermal efficiency by reducing the cooling loss. MEMS heat flux sensor is capable of instantaneous measurement of flux with by using the heat conduction analysis. It is theoretically possible to estimate the advection velocity along the wall using three-point heat flux information. However, due to the size of fluctuations and the influence of vertical velocities, the estimated velocity can vary significantly. Therefore, we are attempting to improve the accuracy of advection estimation by adopting only the results with high consistency in estimated values from four or more multi-point heat flux information. We fabricated three types of multi-points sensors : four-points, five-points and seven-points. We measured the heat flux trends from high temperature air flow with the sensors, using three dimensional heat conduction analysis. Estimation of ethe advection velocity was tested by using delay times of adjacent three heat flux trends measured with the seven-points sensor.
