Center Unitary Plan Wind Research Articles

Supersonic Aerodynamic Characteristics of Proposed Mars '07 Smart Lander Configurations

Supersonic aerodynamic data were obtained for proposed Mars '07 Smart Lander configurations in NASA Langley Research Center's Unitary Plan Wind Tunnel. The primary objective of this test program was to assess the supersonic aerodynamic characteristics of the baseline Smart Lander configuration with and without fixed shelf/tab control surfaces. Data were obtained over a Mach-number range of 2.3-4.5, at a freestream Reynolds number of 1 x 10 6 based on body diameter. All configurations were run at angles of attack from -5 to 20 deg and angles of sideslip of -5 to 5 deg. These results were complemented with computational fluid dynamic predictions to enhance the understanding of experimentally observed aerodynamic trends. Inviscid and viscous full model computational solutions compared well with experimental results for the baseline and three shelf/tab configurations. Over the range tested, Mach-number effects were shown to be small on vehicle aerodynamic characteristics. Based on the results from three different shelf/tab configurations, a fixed-control surface appears to be a feasible concept for meeting aerodynamic performance metrics necessary to satisfy mission requirements.

Design and experimental verification of an equivalent forebody representation of flowing inlets

A method by which a simple equivalent-faired body can be designed to replace a more complex body with flowing inlets has been demonstrated for supersonic flow. An analytically defined, geometrically simple faired inlet forebody has been designed using a linear potential code to generate flow perturbations equivalent to those produced by a much more complex forebody with inlets. An equivalent forebody wind-tunnel model was fabricated, and a test was conducted in NASA Langley Research Center's Unitary Plan Wind Tunnel. The test Mach number range was 1.6-2.16 for angles of attack of -4-16 deg. Test results show that, for the purposes considered here, the equivalent forebody simulates the original flowfield disturbances to an acceptable degree of accuracy.

Planform effects for low-fineness-ratio multibody configurations at supersonic speeds

An experimental and theoretical investigation of planform effects on a low-fineness ratio multibody configuration has been conducted in NASA Langley Research Center's Unitary Plan Wind Tunnel at Mach numbers 1.6, 1.8, 2.0, and 2.16. Experimental and theoretical values of lift, drag, and pitching moment were obtained on three configurations which varied in outboard panel planform only. The three variations were at 65 deg delta, a 70/66 deg cranked arrow, and a 20 deg trapezoidal planform . The purpose of the study was to determine the effect of wing planform on the supersonic aerodynamics and to evaluate the ability of two existing linearized-theory aerodynamic methods to predict these effects. Experimental data showed that the planforms produced the lift, drag-due-to-lift, and pitching-moment characteristics typically found on single-body configurations. However, the data also showed that planform has a minimal influence on zero-lift drag, which is not typical of single-body configurations. Theoretical aerodynamic analysis indicated that codes based on linearized theory adequately predicted the effect of planform on the supersonic aerodynamics.