Static and dynamic calibration of a multi-component sidewall force balance for a transonic Ludwieg tube wind tunnel.

摘要

Experimentation involving transonic flow requires replicating not only the Mach number but also the Reynolds number. Improper matching of the Reynolds number affects the interaction between the shocks and boundary layer on the surface of an airfoil, moving the position of the shock and altering the downstream flow field. Both Mach and Reynolds numbers have a large influence on the lift and drag characteristics of airfoils, amongst other aerodynamic effects, within the transonic regime of flight.;A strain-based, multi-component, sidewall force balance was purchased in 1989 specifically for the transonic Ludwieg tunnel at the University of Texas--Arlington, but proper calibration has not been applied since 1990. Dynamic loads are experienced by the balance, so to ensure that the force balance measures forces and moments properly, static and dynamic calibrations are necessary to eliminate the interference from the tunnel on the balance and the model. The procedures for static and dynamic calibration of the force balance are the main topics of discussion, including calculations, results, and uncertainty analysis.;After calibration, a parametric study was completed on a NACA 0012 wingtip showing the changes in the coefficients of lift and drag with the angle of attack. A comparison was also made with data from a two-dimensional NACA 0012 wing from NASA.