A High Altitude-Low Reynolds Number Aerodynamic Flight Experiment

A sailplane is currently being developed at NASA's Dryden Flight Research Center to support a high altitude flight experiment. The purpose of the experiment is to measure the performance characteristics of an airfoil at altitudes between 100,000 and 70,000 feet at Mach numbers between 0.65 and 0.5. The airfoil lift and drag are measured from pilot and static pressures. The location of the separation bubble and vortex shedding are measured from a hot film strip. The details of the flight experiment are presented. A comparison of several estimates of the airfoil performance is also presented. The airfoil, APEX-16, was designed by Drela (MIT) with his MSES code. A two dimensional Navier-Stokes analysis has been performed by Tatineni and Zhong (UCLA) and another at the Dryden Flight Research Center. The role these analysis served to define the experiment is discussed.

[1]  H. H. Arnaiz.  Flight-measured lift and drag characteristics of a large, flexible, high supersonic cruise airplane , 1977 .

[2]  A. Silverstein,et al.  A Simplified Method for Determining Wing Profile Drag in Flight , 1940 .

[3]  Parviz Moin,et al.  The structure of two-dimensional separation , 1990, Journal of Fluid Mechanics.

[4]  J. Marchman.  Aerodynamic testing at low Reynolds numbers , 1986 .

[5]  L. C. Montoya,et al.  Section drag coefficients from pressure probe transverses of a wing wake at low speeds , 1978 .

[6]  H. Fasel,et al.  Interaction between a Tollmien-Schlichting wave and a laminar separation bubble , 1987 .

[7]  E. Reshotko,et al.  Environment and Receptivity , 1984 .

[8]  Hugh W. Coleman,et al.  Experimentation and Uncertainty Analysis for Engineers , 1989 .

[9]  Robert H. Liebeck,et al.  Low Reynolds Number Airfoil Design for Subsonic Compressible Flow , 1989 .

[10]  T. Mueller,et al.  Visualization of Transition in the Flow over an Airfoil Using the Smoke-Wire Technique , 1981 .

[11]  Mark Drela,et al.  A two-dimensional transonic aerodynamic design method , 1986 .

[12]  R. Howard,et al.  Freestream turbulence effects on airfoil boundary-layer behavior at low Reynolds numbers , 1990 .

[13]  Victor V. Kozlov,et al.  Laminar boundary layer separation: Instability and associated phenomena , 1994 .

[14]  Mark Drela,et al.  Transonic Low-Reynolds Number Airfoils , 1991 .

[15]  James E. Murray,et al.  Piloted simulation study of a balloon-assisted deployment of an aircraft at high altitude , 1992 .

[16]  R. Liebeck,et al.  A Comparison Between Boundary Layer Measurements in a Laminar Separation Bubble Flow and Linear Stability Theory Calculations , 1989 .

[17]  Laura L. Pauley,et al.  Low-Reynolds-number separation on an airfoil , 1996 .

[18]  Siva M. Mangalam,et al.  Simultaneous detection of separation and transition in surface shear layers , 1989 .

[19]  Vernon L Rogallo.  Effects of wing sweep on the upwash at the propeller planes of multiengine airplanes , 1952 .

[20]  Laura L. Pauley,et al.  The unsteady structure of two‐dimensional steady laminar separation , 1993 .

[21]  Thomas J. Mueller,et al.  Low Reynolds Number Vehicles , 1985 .

[22]  M. Gaster,et al.  The Structure and Behavior of Laminar Separation Bubbles , 1969 .

[23]  T. J. Mueller,et al.  Spanwise variation of laminar separation bubbles on wings at low Reynolds number , 1986 .

[24]  P. S. Barna,et al.  Experimental studies on the aerodynamic performance and dynamic response of flow direction sensing vanes , 1976 .

[25]  Mahidhar Tatineni,et al.  Numerical Simulation of Unsteady Low-Reynolds-Number Separated Flows over Airfoils , 1996 .

[26]  C. Friehe,et al.  Fast-Response Aircraft Temperature Sensors , 1992 .

[27]  R. J. Mcghee,et al.  Experimental results for the Eppler 387 airfoil at low Reynolds numbers in the Langley low-turbulence pressure tunnel , 1988 .