Accession Number:

ADA196744

Title:

Modification of an Unsteady Transonic Small Disturbance Procedure to Allow a Prescribed Steady-State Initial Condition

Descriptive Note:

Interim rept. Jan 1987-Jan 1988

Corporate Author:

AIR FORCE WRIGHT AERONAUTICAL LABS WRIGHT-PATTERSON AFB OH

Personal Author(s):

Report Date:

1988-01-01

Pagination or Media Count:

60.0

Abstract:

Many attempts have been made to extend the useful range of the two- dimensional unsteady transonic small disturbance procedure, called LTRAN2. This report describes another such extension. LTRAN2 modifications are described that allow the procedure to determine the geometry corresponding to a prescribed pressure distribution. This new geometry would account for all compressible and viscous effects, and would, therefore, be a much better starting point for the unsteady calculations. We present the transonic small disturbance governing equations and boundary conditions. Then the modifications required for the inverse geometry definition are described. Results for three different airfoils NACA 0012, NACA 64A010, and NLR 7301 are presented and discussed. The NACA 0012 and NLR 7301 results are much improved using this procedure. Keywords Unsteady transonic flow Thin airfoils Unsteady aerodynamics Small disturbance methods Transonic aerodynamics Potential flow TSDTransonic Small Disturbances.

Subject Categories:

  • Aerodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE