# Accession Number:

## ADA059709

# Title:

## Calculation of Aerodynamic Pressure Distributions on Arbitrary Aircraft Geometries Using the Woodward Aerodynamic Analysis Program.

# Descriptive Note:

## Master's thesis,

# Corporate Author:

## AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OHIO SCHOOL OF ENGINEERING

# Personal Author(s):

# Report Date:

## 1977-09-01

# Pagination or Media Count:

## 99.0

# Abstract:

There is a frequent need for accurate aerodynamic force data in preliminary design. Data must be available on many configurations, some of which deviate significantly from existing aircraft. A method which fills the gap between statistically based predictions and wind tunnel testing is a computer solution to the linearized potential flow equations of motion. The Woodward USSAERO program was selected to calculate potential flow force distributions on arbitrary aircraft geometry. Five major aspects of the program insure that the program is capable of supplying the required data. They are the differential equation, boundary conditions, singularity types, matrix operations, and force and moment calculations. In order to operate this program in the preliminary design environment, it was interfaced with existing geometry data bases with a separate Interface program. A third program, the Geometry program, was written to speed the definition of a complete aircraft configuration in a format compatible with several existing analysis programs. It defines arbitrary fuselage geometry as a series of cross-sections using an interactive terminal and digitizer. It defines lifting surface geometry as a series of streamwise airfoil sections with several different airfoil shapes being available. The system of programs were applied to the F-111A aircraft as an example case. The results of that analysis show excellent agreement with wind tunnel data for pressure distributions on the wing at moderately high subsonic Mach numbers.

# Descriptors:

# Subject Categories:

- Attack and Fighter Aircraft
- Theoretical Mathematics
- Computer Programming and Software
- Fluid Mechanics