Date of Graduation
The National Aero-Space Plane (NASP) was conceptually designed for flight at hypersonic speeds. Because its airframe configuration was determined by the need for good high-speed flight performance, its low-speed and ground effect characteristics were poor. The purpose of this investigation was to characterize the ground effect aerodynamic performance of a two-dimensional model of the NASP with thrust simulation. This study included a comparison between experimental and numerical results. The experiments were conducted in the WVU subsonic wind tunnel, while numerical results were obtained using FLUENT, a commercial finite volume CFD code. The aerodynamic characteristics of the two-dimensional NASP model were reported as functions of various parameters such as: model configuration, angle of attack, ground plane proximity and thrust coefficient. In this research program, it was found that the characteristic ground effect lift loss, associated with previously studied three-dimensional hypersonic models operating at low, subsonic speed was related to that measured with a two-dimensional model. In an attempt to improve low-speed take-off and landing performance, the simulated engine exhaust was ducted to the upper aft surface and to the trailing edge of the model in two different configurations. Those two in addition to the base configuration were modeled using CFD to compare with experimental data. The test results demonstrated that exhaust ducting can be used to achieve dramatically enhanced lift coefficient characteristics while in ground effect. Of these configurations, the use of external ducting yielded the most favorable ground effect characteristics for the two-dimensional geometry. Additionally, this was the only configuration which produced positive lift in the take-off configuration. The computational fluid dynamic code used for this research failed to produce accurate coefficient data; however, it was found to estimate the lift curve slopes of each of the configurations with reasonable accuracy. Additionally, trends in the lift, drag and pressure coefficients were also predicted with reasonable accuracy.
Bond, Robert E., "Experimental and numerical aerodynamic characterization of a two-dimensional NASP model in ground effect with thrust simulation." (1997). Graduate Theses, Dissertations, and Problem Reports. 8506.