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PAGE 51.
APFWDIX In
A HIGH SPEED I NVESTIGATItBl
MXEL
IN ti
OF THE BURNELLI XB-A64
N. A. C. A.
8- FOOT HIU-I-SPEED
BY EI3hUND
V.
WIND TUNNEL
LAIRINE.
HIGH SPEED PosslBILITIES
OF A 0.16 SCALE MODEL OF THE
AIRCRAFT &APOAAtIOtl
x8-AB-3 DESIGN WERE INVESTIBATED
IN
Tt&
&JRNELLI
N. A. C. A. 8-FOOT HIGH
0.65 WITH CORRESPONDING
PROVIDE
THE
SPEED WI ND TUNNEL AT hlrCH NUMSERS .FROY 0.18
TO
FCEYNOLDS NUMBERS OF 2,500,OOO TO 7,000,OOO.
IkA6
UEASUREMENTS WERE YADE WITH FIXED
TRANSITION
IN ORDER TO
A SETTER BASIS FOR THE ESTIUATION
OF THE FULL-SCALE
DRAG
COEFFICIENT
INCRELIENTS~
STATIG PRESSURE YEASUREL~ENTS WERE urs~~ IN
ORDER TO ESTIYATE
THE CRITIOAL
SPEED.
THE RATE OF AIR FLOW AND INTERNAL HEAD I.088
IN THE OOOLINQ DUCTS WERE ALSO MEASURED.
AT 20,000
FEET ALTITUDE
AND AT 00 ANGLE OF ATTACK THE YODEL
WOULD HAVE A CRITICAL
SPEED OF APPROXIUATELY
376 UILES PER HOUR.
HOWEVER, IF THE HATCH AND FUSELAGE LOWER SURFACE WERE t7E#8IGNED THE
CRITIOAL
SPEED UNDER THE SAM CONDlTIONS GOULD PROBABLY SE INCREASED TO
APPROXIUATELY
440 UILES
PER HOUR.
THE EXTERNAL DRAG OF THE DUOT APPEARED Too HIGH lNDlCATlNS
THAT A WORE SUITABLE
DESIGN LOCATING THE EXIT
FARTHER
AFT WOULD SE BENEFICIAL*
INTFUIUCTION.
THE MATERIEL DIVISION
OF THE UNITED STATES ARTY AIR CORPS RETO INVESTIGATE
THE HIGH-SPEED
POSSlslLlTlES
QUESTED THE N. A. c. A.
OF THE BURNELLI
AIRCRAFT CORPORATION XB-AB-3
DESIGN.
A YODEL OF THIS
AIRPLANE
SUITABLE
FOR TESTING
IN THE N. A. c. A. 8-FOOT
HIGH-SPEED
WIND TUNNEL WAS P~VIDED
BY THE BURNELLI
AIRCRAFT
CORPORATION.
THE
TEST
PWGRA~~E
WAS ARRANGED BY REPRESENTATIVES
OF THE
MATERIAL DIVISION,
THE BURNELLI
AIRORAFT CORPORATION,
AND THE N. A. C.
To PROVIDE DATA TO AID IN THE PERFORYANOE ESTIUATEB
AND TO STUDY THE
COUPRESSIBILITY
EFFEOTS AS OUTLINED
IN REFERENCE 1.
THE MACH NWBER
A.
RANGE FOR NOST OF THE TESTS EirTENDED FROM 0.18
TO 0.65 GIVING
A
CORRESPONDIll
f?EYWOLDS NUMBER RANGE OF 2,500,000 TO 7,000,000 BASED
ON THE YEAM KA0DYW~lC
STATIO
PMESS~~S
WORD,
24.34
YASUREUENTS
INCHES~
OF THE COM’LETE
WERE TAKEN
YDDEL.
AT THE CRITIOAL
.LOOATIONS
ON THE MODEL IW ORDER TO DETERMINE
THE EFFECTS OF OOLPRESSlslLlTY
THE DRAG YEASUREUENTS WERE UADB
To ESTIUATE
THE ORITIOAL
SPEED.
AWD
WITH
TR@lSlTlON
FIXED AT THE PROBABLE FULL-SOALE
LOOATIOW WHENEm
IICESSARY IN ORDER To PROVIW
4 SETTER BASIS FOR ESTIUATION
OF THE CULLSCALE DRAS COEFFICIENT
HEAD LOSS
IN
INOREYNTS.
THE COOLING
THE TESTS
THE RATE OF AIR
DUOTS WERE AL90
FLOW AND INTERNAL
YEASURED.
WERE COMWIOTED WITH THE ASS~STAMCE
OF MESSRS.
8ERKow
AYD APPLESATE,
REPRESENTATIVES
OF THE BURNELLI
AIRORAFT CORPORATION,
AND m.
J. A. ~IOOHE OF THE MATERIEL DIVISION
LIAISON
OFFIOE.
-
UNITED STATES ARMY AIR CORPS TEST fESULTS
BURNELLI F IWIER
BOMER X-MB-3
SEPTEUBER
FAOU
STUDIES
AND THE
THE
of
AIR
THE
CORPS,
FOLLOWING
RESEARCH
1939
MADE BY THE
THE MILITARY
ADVANTAGES
19 -
BURNELLI
ADAPTIEILITY
OVER
THE
Co.;
of
ORTHODOX
THE
THE
BASIC
STREAMLINED
NACA
DESIGN
HAS
DEAD-WEIGHT
FUSELAGEe
I.
THE
COEfflClENT
Al RPLANE
2.
THE
COEFFICIENT
3.
THE
LIFTING
4.
5.
Of
FROM WI&I) TUNNEL
NYU
THE
THE
DESIGN
THE
Of
AIR
BETTER
1T IS
TIME
of
LlfT
18
GREATER*
LOWEST
HAS DISTINCT
POWER PLANTS,
KNOWN FOR ANY USEFUL
IS
ADVANTAGE
APPARENTLY
ELEMENT
IN
Of
THE
of
LENDS
TO
GooD
fAcToR
IT8
fULLEST
TO
IN
AND
PHASE.
dAfETy=
THE
TYPE.
OPINION
PRODUCTION
VALUABLE
CONTRACT8
TIME
CAN BE
EXTENT.
AIRPLANE
6
of
SPEED
THE
NACA
EVERY
FUSELAGE
AND IN
TO HIGH
PRODUCTION
BY THE
GOOD IN
AND THEREFORE
A CHEAPER
REfERRED
CONDUCTED
CONSTRUCTION
ML
FUSELAGE6
STREAMLINED
ITSELf
ANY DESIGN
INVOLVED
STREAMLINED
EXTREMELY
FOR THE
ARMAMENT AND ALL
EXCEPTIONALLY
THAN
SIMPLE
ADVANTAGES
SOWS,
ALREADY
IS
HIGHER
CORPS
THE
TEST8
EMBODIED
THAN
ELEUENT
7.
THE
PERFORMANCE
DESIGN
THE
TAKEN
I3
ACCESSOR I ES OVER
CONSIDERABLY
6.
DRAG
PUSELAGE
INSTALLATION
OTHER
Of
TODAY.
ABOVEe
TO BUILD
BECAUSE
Of
THE