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Accession Number:
ADA278339
Title:
Transition Receptivity and Control: Computations
Corporate Author:
ARIZONA STATE UNIV TEMPE DEPT OF MECHANICAL AND AEROSPACE ENGINEERING
Report Date:
1994-02-01
Abstract:
We modeled the receptivity of the laminar boundary layer on a semi- infinite flat plate with a modified-super-elliptic leading edge using a spatial direct numerical simulation. The incompressible flow was simulated by solving the governing full Navier-Stokes equations in general curvilinear coordinates by a finite-difference method. First, the steady basic-state solution was obtained in a transient approach using spatially varying time steps. Then, time-harmonic oscillations of the freestream streamwise velocity, modeling sound or spanwise vorticity, were applied as unsteady boundary conditions, and the governing equations were solved to evaluate the spatial and temporal developments of the perturbation leading to instability waves in the boundary layer. The effects of leading-edge radius and geometry on receptivity were determined. The work was closely coordinated with the experimental program. The computational work was also extended to solve the parabolized Navier-Stokes equations for the evolution of Gortler vortices in the presence of concave and convex curvature. Experiments were conducted on the receptivity of T-S waves to freestream sound in four different cases. 1 Two-dimensional roughness elements 2 the interaction and control of T-S waves with 2-D roughness 3 three-dimensional roughness clements and 4 the leading edge. T-S wave amplitudes were measured as a function of freestream sound level and the roughness height for both 2-D and 3-D roughness elements.
Descriptive Note:
Final technical rept. 15 Mar 1990-30 Sep 1993
Pages:
0050
Distribution Statement:
Approved for public release; distribution is unlimited.
Contract Number:
AFOSR-90-0234
File Size:
2.83MB
