Intake Pipes Evaluation: Comparison between Paddle-Wheel and Hot-Wire Anemometry Methods

Abstract

The aerodynamic behaviour of the intake pipes of direct injection diesel engines has usually been quantified by means of swirl number and the discharge coefficient. In order to validate these parameters an experimental method based on the hot-wire technique has been applied to the steady flow rig where the former parameters are measured. This method allows the measurement of the three components of the velocity referred to an orthogonal coordinate system by placing the probe parallel to these three directions. The results obtained are presented and analysed in this paper. The comparison between the two measurement techniques has been done in terms of discharge coefficients, angular momentum flux and paddle-wheel speeds, calculated by integration of the measured velocity field in the case of the hot-wire results. The comparison between the values of the angular momentum flux allows the conclusion to be made that some of the hypotheses assumed by the paddle-wheel method are not accurate.