In this work we consider the linear stability of a sub-to-super inviscid transonic stationary wave of a one-dimensional model of isentropic compressible flows through a nozzle of varying area. This sub-to-super inviscid transonic stationary wave is newly founded by the authors using the geometric singular perturbation theory. The main result of this work is to show that the sub-to-super invisci...

The problems of steady, inviscid, isentropic, irrotational supersonic plane flow passing a body with small thickness ratio was solved by the linearized theory, which is first approximation at and near surface but fails far fields from body. Such problem W.D. Hayes’ “pseudo-transonic” nonlinear theory in 1954. This field disturbance reexamined this study using asymptotic expansion theory. A syst...

LE leading edge Transonic free-to-roll and static wind tunnel tests for four military aircraft – the AV-8B, the F/A-18C, the pre-production F/A-18E, and the F-16C – have been analyzed. These tests were conducted in the NASA Langley 16-Foot Transonic Tunnel as a part of the NASA/Navy/Air Force Abrupt Wing Stall Program. The objectives were to evaluate the utility of the freeto-roll test techniqu...

The time accuracy of the exponentially accurate Fourier time spectral method (TSM) is examined and compared with a conventional 2nd-order backward difference formula (BDF) method for periodic unsteady flows. In particular, detailed error analysis based on numerical computations is performed on the accuracy of resolving the local pressure coefficient and global integrated force coefficients for ...

An optimization procedure aimed at the design of multicomponent airfoils for high-lift applications is described. The procedure is based on a multiobjective genetic algorithm; two #ow solvers have been coupled with the genetic algorithm: a viscous}inviscid interaction method, based on an Euler #ow solver and an integral boundary layer routine, and a method based on a full potential #ow solver. ...

This paper describes the application of the leastsquares spectral element method to compressible flow problems. The method is described and results are presented for subsonic, transonic and supersonic flow problems over a bump.

SUMMARY Brief consideration of current approaches to the prediction of unsteady wing loading in mixed subsonic and supersonic flow shows a wide variety of method and a clear need for economy in transonic aerodynamic calculations for flutter clearance in subsonic flight. In support of measurements of steady and oscillatory pressure distributions on a particular wing, an approximate theoretical t...