Determination of ram coefficients based on front end pressure distributions

Abstract

The objective of this experiment was to determine a relationship between the pressure distribution on the generic front fascia shape of a new vehicle and the corresponding ram correlation coefficients. For this purpose, a simple theoretical model is presented which establishes the expected relationships between the pressure distribution and ram correlation coefficients. An aspirated cylinder in cross flow was taken as an idealized representation of a vehicle front end and the experimental investigation was carried out in the Texas Tech University Wind Tunnel. Results of the measurements are in agreement with the theoretical expectations for openings which are located at or near the stagnation point or at the location of a pressure coefficient equal to one on the front of the model. For openings significantly further from the stagnation point or close to the location of a zero pressure coefficient on the model, the experimentally determined ram correlation coefficients exhibit less agreement with the theoretical expectations