Method permits analysis of noncircular bodies and calculation of wing-body interference effects in presence of body closure, two features not previously available. In addition, use of vortex distribution, having linear variation in streamwise direction, results in improved chordwise pressure distributions on wing and tail surfaces

Fox, C. H. J.

Woodward, F. A.

English

NASA Technical Reports Server

March 1974	 B73-10470 
S NASA TECH BRIEF Langley Research Center
	
1 0 
_ 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
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Improved Method for Aerodynamic Analysis of Wing-Body-Tail

Configurations in Subsonic and Supersonic Flow 
S
The problem: 
A better method was needed for assisting in aircraft 
analysis. 
The solution: 
A new method has been developed for calculating the 
pressure-distribution and aerodynamic characteristics of 
wing-body-tail combinations in subsonic and supersonic 
potential flow. A computer program has been developed 
to perform the numerical calculations. 
How it's done: 
The configuration surface is subdivided into a large 
number of panels, each of which contains an aero-
dynamic singularity distribution. A constant-source dis-
tribution is used on the body panels; and a vortex 
distribution, having a linear variation in the stream-
wise direction, is used on the wing and tail panels. The 
normal components of velocity, induced at specified 
control points by each singularity distribution, are 
calculated and make up the coefficients of a system of 
linear equations, relating the strengths of the singulari-
ties to the magnitude of the normal velocities. The 
singularity strengths, which satisfy the boundary condi-
tion of tangential flow at the control points for a given 
Mach number and angle of attack, are determined by 
solving the system of equations using an iterative 
procedure. Once the singularity strengths are known, 
the pressure coefficients are calculated; and the forces 
and moments acting on the configuration are determined 
by numerical integration. 
The new method contains a number of unique 
features, which are considered improvements over former 
methods available for solving the problem. The u, v, and 
w components of velocity, induced by surface distri-
butions of sources and vortices at arbitrary points in the 
flow field, are derived by an extended version of a
current theory. The new method includes panels inclined 
to the free-stream direction in both subsonic and super-
sonic flow, which allows a complete-surface panel 
representation of the configuration and a corresponding 
improvement in the aerodynamic solution. In particular, 
the new method permits the analysis of noncircular 
bodies and the calculation of wing-body interference 
effects in the presence of body closure, two features not 
available previously. In addition, the use of a vortex 
distribution, having a linear variation in the streamwise 
direction, results in improved chordwise pressure dis-
tributions on wing and tail surfaces. 
Notes: 
I. The computer program is written in FORTRAN IV 
for the CDC 6600 computer; it occupies 70,000 
(octal) words and operates in the overlay mode. The 
program requires five peripheral-storage disk files, 
in addition to the input and output files. 
2. Inquiries concerning this program should be directed 
to:
COSMIC 
112 Barrow Hall 
University of Georgia 
Athens, Georgia 30601 
Reference: LAR-1 1305
Source: C. H. Fox
Langley Research Center 
and F. A. Woodward of
Analytical Methods, Inc., 
under subcontract to
Aerophysics Research Corp.
under contract to
Langley Research Center 
(LAR.1 1305) 
Category 09, 06 
This document was prepared under the Sponsorship of the National
	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States
	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States
	 will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19730000470 2020-03-17T07:31:55+00:00Z


Improved method for aerodynamic analysis of wing-body-tail configurations in subsonic and supersonic flow

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