AERODYNAMIC TESTING OF ROAD VEHICLES - OPEN THROAT WIND TUNNEL ADJUSTMENT

Download or read book AERODYNAMIC TESTING OF ROAD VEHICLES - OPEN THROAT WIND TUNNEL ADJUSTMENT written by Road Vehicle Aerodynamics Forum Committee and published by . This book was released on 1994 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: As a simulation of road driving, wind tunnel testing of full-size vehicles produces certain errors in the aerodynamic forces, aerodynamic moments, and surface pressures. The magnitude of these errors, in general, depends on the following: aFlow quality bDetermination of the reference dynamic pressure cWind tunnel floor boundary layer dTest section geometry and position of the car within that geometry eShape of the vehicle fBlockage ratio: The ratio of the cross-sectional area of the vehicle to the cross-sectional area of the wind tunnel nozzle gWheel rotation hInternal flow in the modelThe SAE Standards Committee, Open Throat Wind Tunnel Adjustments had as a goal to document the knowledge of the influence of model interference on wind tunnel test results for automotive open jet wind tunnels. This document contains the following information related to this subject: aDesign data of open throat wind tunnels bA summary of published and unpublished test data cDocumentation and theoretical explanation of various blockage correction procedures for automotive tests dCritical evaluation of blockage correction procedures, especially in relation to other influences, such as test section geometry, position of the car, floor boundary layer, etc. eRecommendation of a calibration procedure to determine the effect of blockage and other influences in each individual wind tunnelAn initial goal of the committee, to recommend a well proven correction procedure for automotive open jet wind tunnels based on blockage theory (Figure 1), could not be established at this time. The reason is that, besides blockage, other factors, such as test section geometry, are at least as influential as pure blockage. As these influential parameters are wind tunnel specific, a general valid adjustment procedure is presently not available. The only change to this document was the title.