AAWSAP DIRD, Space Access: Where We’ve Been and Where We Could Go, March 2010

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1,200°F
1,500° F
800 °F
" 3,800°F
RLE=1.6 in.
2,200° F
UNCLASSIFIED/ /FOR OFFI@IAL l:ISE OHL¥
Figure 18, radiation equilibrium skin temperature is the skin temperature that results
when the radiated thermal energy stemming from the skin temperature equals the
input aerodynamic heating minus any conduction into the airframe.
900 °F
Upper
Surface
!
l
•4,Joo°F
Lower
ALE= 0.5 in.
Surface
• 4,200°F
1,ooo·F
Figure 18. FDL-7C/D, Model 176 Entry Temperature Distribution. Upper-surface heating is minimized by
cross-section geometry.
Figure 19 is a thermographic phosphor
image of the model in Figure 17 at a 12­
degree angle of attack (maximum L/D
ratio) at mach 12. Even at mach 12,
there are vortices embedded in the
boundary layer. The three black dots are
heat transfer gauges that were used to
establish the value for qrefin Figure 19.
The stagnation heat transfer was 25
times the reference value. This
technique, when calibrated with the
,, - no
reference heat transfer gauges, provided
a rapid and accurate means to determine
heat transfer distributions with a
minimum of installed gauges. The
technique was adopted by other wind
tunnel facilities, including the Arnold
Engineering Development Center at
Tullahoma, Tennessee.
Figure 19. Even at Mach 12, Embedded Vortices in
the Boundary Layer Alter the Local Heat Transfer
UNCLASSIFIED/ /FOR. OFFICI CIs. flili Qllls.¥
19