REPORT
DESIGN
CHARTS
ANGLES
AND
WAKE
PLAIN
By ABE Langley
111 ():_4--3!_--
I
FOR
AND
No. 648
PREDICTING
CHARACTERISTICS FLAPPED
SILVERSTEIN Memorial
DOWNWASH
and
Aeronautical
WINGS
S. KATZOFF Laboratory
BEHIND
NATIONAL
ADVISORY
COMMITTEE
HEADQUARTERS,
NAVY
BUILDING,
LABORATORIES, Created study act
of
by
the
act
of
Congress
problems
approved
of
March
approved
flight
2,
1929.
S.
Code,
The
members
3,
Title
1915,
50,
are
FIELD,
for
Sec.
AERONAUTICS
WASHINGTON,
LANGLEY
March
(U.
FOR
the
Its
by
C.
supervision
151).
appointed
D.
VA.
the
and
direction
membership
was
President,
and
of
the
increased
serve
as
such
scientific to
15
by
without
compensation. JOSEPH
S.
AMES,
Ph.
Washington, WII.LIS RAY Chief,
D.
D. GREGt;,
United
WILLIAM
D.,
P.
SYDNEY
Chairman,
Eng.,
Vice
D.,
States
Chairman,
Weather
MACCRACKEN,
Washington, G.
J.
D.
Exeeuti_e
DENIS
Commillee,
Bureau. D.,
Vice
('hairman,
So.
Director, B.
Chief, HARRY Port
National COOK, Bureau
F.
Bureau
Rear of
of
Aeronautics,
Navy
M.
Washington,
States
Department.
Long
N.
E.
REID,
ROBINS,
W.
LEWIS,
Engineer-in-Charge, J.
Director F.
VICTORY,
Langley IDE,
Technical
of
Division,
WARNER,
Aeronautical
Memorial
of
Research
Needs of
Prevention
Unified scientific
AERONAUTICAL
Aeronautical in
problems
conduct,
for
all
on
the
of
flight.
General,
Field,
United
States
Army,
Department.
Laboratory,
Europe,
Paris,
LABORATORY
of
Research of of
Military
and
Langley
AIRCRAFT
STRUCTURES
AIRCRAFT
ACCIDENTS
Civil
AND
fundamental
DESIGNS
Aviation
Programs
Duplication of
Inventions OFFICE
OF
AERONAUTICAL
INTELI,IGENCE
WASHINGTON,
agencies,
Field,
France
Problems
VA.
research
Wright
D.,
INVENTIONS
Consideration
FIELD,
Corps,
Air
Research
MATERIALS
Allocation
LANGLEY
States
COMMITTEES
Preparation
MEMORIAL
Commerce. United
Ohio.
FOR AIRCRAFT
Coordination
LANGLEY
Sc.
of Air Corps, War WRIGHT, Sc. D.,
AERODYNAMICS AIRCRAFT
of
General,
Secretary
Assistant
TECHNICAL
PLANTS
Department
Brigadier
Y.
JOHN
POWER
Navy,
Ohio.
Dayton,
Island,
JOlIN J.
Chief ORVILLE
Navy,
A.,
GEORGE
HENRY
W.
P.
States Department.
LL.D.,
Greenwich, Conn. OSCAR WESTOVER, Major
Standards. United
United Navy
City.
Mat6riel
EDWARD
Admiral,
GUGGENHEIM,
LINDBERGH,
Dayton,
D., Institution.
Captain,
MULLIGAN, J. S. D., Director of Air Commerce,
AUGUSTINE
Executive
C.
ABBOT,
A. York
Army, Chief
Secretary, Smithsonian LYMAN J. BRIGGS, Ph. D., ARTHUR
KRAUS,
of Aeronautics,
CHARLES
Chairman,
New
C. So.
Committee, CIIARLES
M.
Bureau
Baltimore, Md. I)AVID W. TAYLOR,
of and
D. C.
Collection, classification, dissemination of scientific
nical
information
on
compilation, and tech-
aeronautics.
Va.
REPORT
No.
648
DESIGN CHARTS FOR PREDICTING DOWNWASH ANGLES AND CHARACTERISTICS BEHIND PLAIN AND FLAPPED WINGS l]_,
+\I+I:
_II+\I,:RSTEIN
SUMMARY
l+,'quatiol_s aml desigl_ c/torts are given for predicting the doumwash al+gles a_(1 the wake charachristics .for power-off eoT+ditio_+s behimt plain and flapped wings oJ the types used in modern desig_ practice. The dou,mrash charts cover the cases of elliptical wings amt wil_gs of taper ratios 1, 2, 3, aTM 5, with aspect ratios of 6, 9, arid 12, hadr_g flaps em, eri_g O, gO, 70, aTM 100 }>ereel_t of the ,_pa_. Curves of the spa_ load distributio_+s for all these cases are i*wluded. Data o_ the lift aml tile drag q[ flaplJed airfoil secti+ms aml curces for fiI_di,_g the coldribution of the flap to the total wb_g lljt .for diff_re?it types of flap al_dJor the entire ra,ge of flap spans are ah.o inel'uded. The wake width, and the distribution of dyrmmie pressure across the wake are given in terms of the profile-dra 9 eoeflieiel_t and the distance behind the whig. A method of estimating the wake position is olso give_+. The equatlons and the charts are based on theory that has been show_t ia a previous report to be in a.qreemeT_t with experime_ t. INTRODUCTION In a recent for predicting for power-oil' loading. The
paper (reference 1) methods are developed
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