Wind Tunnel Tests Employing Temporal and Spatial Variations in Mass Transfer Distribution Through a Conical Surface to Control Aerodynamic Pitching Moment Characteristics

摘要

A unique apparatus was created which permits the support of a conical model in a hypersonic wind tunnel with small pitch damping due to the apparatus, and at the same time provides a means for blowing through four separate (aft, forward, top, bottom combinations) model surface areas. Tests were made without mass transfer, with mass transfer produced by a subliming material, and with mass transfer produced by blowing through a porous surface. These tests provided additional confirmation that mass transfer from a surface will, in itself, significantly influence the pitch damping characteristics of a conical shape, whether its origin is in a heat transfer related phenomenon (such as ablation or sublimation) or an independently controlled flow process such as is represented by blowing through the conical surface. In addition, these tests provided an opportunity for shakedown of the blowing flow control apparatus; however, it was not possible to carry the blowing study into the parametric investigation initially planned. (Author)