EVALUATION OF THE CONSTANT PRESSURE PANEL METHOD (CPM) FOR UNSTEADY AIR LOADS PREDICTION

This paper evaluates the capability of the constant pressure panel method (CPM) code to predict unsteady aerodynamic pressures, lift and moment distributions, and generalized forces for general wing-body configurations in supersonic flow. Stability derivatives are computed and correlated for the X-29 and an Oblique Wing Research Aircraft, and a flutter analysis is carried out for a wing wind tunnel test example. Most results are shown to correlate well with test or published data. Although the emphasis of this paper is on evaluation, an improvement in the CPM code's handling of intersecting lifting surfaces is briefly discussed. An attractive feature of the CPM code is that it shares the basic data requirements and computational arrangements of the doublet lattice method. A unified code to predict unsteady subsonic or supersonic airloads is therefore possible.

[1]  Kari Appa,et al.  Integration of a supersonic unsteady aerodynamic code into the NASA FASTEX system , 1987 .

[2]  J. Giesing,et al.  Oscillatory supersonic lifting surface theory using a finite elementdoublet representation , 1975 .

[3]  Ping-Chih Chen,et al.  A Harmonic Gradient Method for Unsteady Supersonic Flow Calculations , 1985 .

[4]  I. Lottati,et al.  Nonplanar, Subsonic, Three-Dimensional Oscillatory Piecewise Continuous Kernel Function Method , 1985 .

[5]  F. A. Woodward An improved method for the aerodynamic analysis of wing-body-tail configurations in subsonic and supersonic flow. Part 1: Theory and application , 1973 .

[6]  W. Rodden,et al.  A doublet-lattice method for calculating lift distributions on oscillating surfaces in subsonic flows. , 1969 .

[7]  A. M. Cunningham,et al.  Oscillatory supersonic kernel function method for interfering surfaces , 1974 .

[8]  Christopher J. Borland,et al.  Prediction of Unsteady Aerodynamic Loadings on Non-Planar Wings and Wing-Tail Configurations in Supersonic Flow. Part 1. Theoretical Development, Program Usage, and Application , 1972 .

[9]  K. Appa Kinematically consistent unsteady aerodynamic coefficients in supersonic flow , 1970 .

[10]  Earl H. Dowell,et al.  Doublet-Point Method for Supersonic Unsteady Lifting Surfaces. , 1984 .

[11]  K. Appa,et al.  Constant pressure panel method for supersonic unsteady airload analysis , 1987 .

[12]  M. Hounjet,et al.  Improved Potential Gradient Method to Calculate Airloads on Oscillating Supersonic Interfering Surfaces , 1981 .

[13]  Robert A. Canfield,et al.  ASTROS - A multidisciplinary automated structural design tool , 1987 .