曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
taught me this subject.l am grateful to Prof. Colin P. Britcher and Dr. Atul Kelk~
for reviewing various parts of the manuscript and making helpful suggestions.
I greatly appreciate the discussions I had at various times with Walt England,
Richard Powell, Dr. Eric Queen, Dr. Suresh Josbi, Dr. D. M. Rao, Fred Lalman,
and H. Paul Stough. I am thanldul to Dr. Sudhir Mehrotra for providing me with
the facilities to work on this project and to Charles Eldred and Larry Rowell for
their support and encouragement to bring this project to a successful completion.
I appreciate the help of Dr. K. Sudhakar in the preparation of the manuscript.l am
also thankful to John Aguire for his help with computers.
I am especially grateful to my wife, whose constant love, affection, and untiring
support has sustained me all the time during this project.lcannot thank her enough
for her patience to put up with me on countless weeknights, weekends, and holidays
when I was working on tlus book. I am deeply indebted to my son and daught"9rJ
whose love and affection have given me the inspiration to work on this text.
I certainly owe a sense of gratitude to various authors on this subject,including
C. D. Perkins, R. E. Hage, B. Etkins, A. W. Babister, B. W. McCornuck, Angelo
Miele, R. C. Blakelock, and many others whose works have made a significant
contribution to this subject and have been useful to me in the preparation of che
material presented in this text.
Finally, I would like to record my appreciation to AIAA for publishing this
as an AIAA textbook. The help and encouragement of all t,he editorial staff of
AIAA and in particular that of Rodger Williams and John Calderone is gratefully
acknowledged.
Bandu N. Pamadi
July 1998
1
Review of Basic Aerodynamic Principles
1.1 Introduction
The performance, stability, and control character:istics of an airplane depend on
the aero+dynamic forces and moments acting on it that,in tum,'depend on the shape
and size of the body, the attitude of the body relative to the airstream, the density p
and viscosity y of the air, velocity of the body Voo, and the speed of sound a in air.
By a dimensional analysis, it can be shown that a number of these variables can
be grouped into two important nondimensional parameters, the Reynolds number
Re and the Mach number M.
The Reynolds number is the ratio ofinertial forces to viscous forces.
L force
Re = 3 uff (1.1)
s force
We assume
Change in momentum/time
= S~ear stress x Area
d 1
dt = tune
Voo
=L
av voa
ay = L
(1.2)
(1.3)
(1.4)
(1.5)
(1.6)
(1.7)
where L is the characteristic dimension (length) of the body. Then
p Voo L
Re - - (1.8)
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PERFORMANCE, STABILITY, DYNAMICS, AND CONTROL1(7)
