Thin-Layer Navier-Stokes Solutions for a Cranked Delta Wing
Abstract
For thin, highly swept wings operating at moderate to high angles of attack, flow over the wing is dominated by formation of leading edge vortices. These vortices produce a minimum pressure which results in an additional lift increment. The lift increment is nonlinear with angle of attack and cannot be accurately predicted using present design methods. Thin-layer Navier-Stokes equations were used to calculate flow over a straight delta wing and a cranked delta wing. The straight delta wing was used as the test case due to the availability of both experimental and numerical procedure. The computer code uses an implicit, time marching algorithm developed by Beam and Warming. The solution is marched in time until a steady state is achieved. The code is approximately factored and diagonalized in order to reduce computational work. A solid state disk is used to allow for the large grid needed for a 3-D solution. Thin-layer Navier-Stokes equations are capable of accurately calculating vortical flows. The cranked delta wing exhibited flow similar to a straight delta wing upstream of the crank. The vortex generated at the crank quickly became paired with the vortex from the front of the wing. Vortex location aft of the crank changes with streamwise location. Grid resolution is important when trying to calculate vortical flows due to the large gradients in both spanwise and normal directions. The solid state disk can be used to run problems that require more computer memory than is available. Optimization of the program input/output should be done for running the code with the solid state disk to reduce central processor unit time and job cost. Keywords: Numerical analysis; CFD; Aerodynamic lift. Theses
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1988
- Accession Number
- ADA203292
Entities
People
- Francis R. Smith
Organizations
- Air Force Institute of Technology