A review of scale effects in unsteady aerodynamics

Abstract The importance of scale effects is recognised generally in steady aerodynamics but is often ignored in unsteady aerodynamics. An attempt is made to remedy this situation by the compilation of a review of information on the influence of Reynolds number from a wide range of unsteady aerodynamic tests, with particular reference to wing flows. The unsteady tests considered are buffet and buffeting, dynamic tests of aerofoils and wings, pressure measurements, oscillatory control surface derivatives, and stability derivatives. The review suggests that for the usual recommended model conditions with fixed transition, scale effects are small for fully-attached or well-separated flows, but may be large close to incipient separation. With fixed transition extrapolation from model to full scale Reynolds numbers is usually possible. In contrast, with free transition scale effects can be large for both attached and separated flows. Much more research is needed into the magnitude of scale effects on unsteady flows at transonic speeds. Some test cases for the prediction of scale effects in unsteady aerodynamics are suggested. This review combines material presented by the author in Paper 3.4.1 ICAS-90 Proceedings (Stockholm) and Paper 27 AGARD CP 507 October 1991 (San Diego).

[1]  D. J. Cockrell,et al.  Measurements of aerodynamic forces on unsteadily moving bluff parachute canopies , 1987 .

[2]  D. G. Mabey,et al.  Beyond the buffet boundary , 1973, The Aeronautical Journal (1968).

[3]  D. G. Mabey,et al.  A review of rigid body response on sting supported models at high angles of incidence , 1991 .

[4]  P. R. Ashill,et al.  The air-injection method of fixing boundary-layer transition and investigating scale effects , 1987 .

[5]  Mohamed Gad-el-Hak,et al.  The pitching delta wing , 1985 .

[6]  D. G. Mabey,et al.  Aeroelastic oscillations caused by transitional boundary layers and their attenuation , 1987 .

[7]  E. Schmidt.  Standard Dynamics Model Experiments with the DFVLR/AVA Transonic Derivative Balance, , 1985 .

[8]  H. Triebstein,et al.  Investigation of unsteady subsonic spoiler and flap aerodynamics , 1987 .

[9]  Dennis G. Mabey,et al.  Analysis and Correlation of Data on Pressure Fluctuations in Separated Flow , 1972 .

[10]  D. E. Davies.  Calculation of unsteady generalised airforces on a thin wing oscillating harmonically in subsonic flow , 1963 .

[11]  W. G. Johnson,et al.  Results of buffet tests in a cryogenic wind tunnel , 1982 .

[12]  Lars Eric Ericsson.  Effect of boundary-layer transition on vehicle dynamics , 1969 .

[13]  Peter F. Lorber,et al.  Unsteady Stall Penetration Experiments at High Reynolds Number , 1987 .

[14]  D E Davies.  Theoretical Determination of Subsonic Oscillatory Airforce Coefficients , 1976 .

[15]  Dennis G. Mabey.  Buffeting criteria for a systematic series of wings , 1989 .

[16]  L. L. Erickson.  Transonic single-mode flutter and buffet of a low aspect ratio wing having a subsonic airfoil shape. , 1974 .

[17]  A. Townsend.  The Structure of Turbulent Shear Flow , 1975 .

[18]  Gerald N. Malcolm,et al.  Flow visualization study of vortex manipulation on fighter configurations at high angles of attack , 1987 .

[19]  D. G. Mabey.  On the prospects for increasing dynamic lift , 1988, The Aeronautical Journal (1968).

[20]  Robert A. Kilgore,et al.  Flight Simulation Characteristics of the Langley High Reynolds Number Cryogenic Transonic Tunnel , 1974 .

[21]  R. Houwink,et al.  A wind-tunnel study of the flutter characteristics of a supercritical wing , 1981 .

[22]  D. G. Mabey.  Some remarks on dynamic aeroelastic model tests in cryogenic wind tunnels , 1975 .

[23]  D. G. Mabey,et al.  Some Aspects of Aircraft Dynamic Loads Due to Flow Separation Meeting (65th) Held in Cesme, Turkey on 4-9 October 1987 , 1988 .

[24]  Lewis B. Schiff,et al.  Recent developments in rotary-balance testing of fighter aircraft configurations at NASA Ames Research Center , 1985 .

[25]  H H Pearcey,et al.  The Interaction Between Local Effects at the Shock and Rear Separation - A Source of Significant Scale Effects in Wind-Tunnel Tests on Aerofoils and Wings, , 1968 .

[26]  L. Carr.  Progress in analysis and prediction of dynamic stall , 1988 .

[27]  D. G. Mabey,et al.  Measurements and calculations of steady and oscillatory pressures on a low aspect ratio model at subsonic and transonic speeds , 1987 .

[28]  Andrew Davies.  A comparative study of vortex flows in wind and water tunnels , 1987 .

[29]  D. G. Mabey,et al.  A summary of measurements of steady and oscillatory pressures on a rectangular wing , 1988, The Aeronautical Journal (1968).