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ScienceDirect
Procedia Engineering 00 (2014) 000–000
www.elsevier.com/locate/procedia
“APISAT2014”, 2014 Asia-Pacific International Symposium on Aerospace Technology,
APISAT2014
Experimental Studies on AeroThermodynamic Environments of the
Interaction Area between the Wing and the Arc Board in Arc Wind
Tunnel
XU Kao*, CHEN Lianzhong, LIU Xiang
China Academy of Aerospace Aerodynamics，Beijing，100074 China
Abstract
The experimental studies on aero thermodynamic environments of the interaction area between the wing and its baseboard (the
arc board) were conducted in the arc wind tunnel. In the experiments, the angle between the fluid from the nozzle and the boardwing was 15 degrees and the coming Mach numbers were5.1 and 5.8. Some cold wall heat fluxes on the board near the wing foot
and the forepart of the wing tine were measured. The results showed, for the board near the wing foot, the cold wall heat fluxes
first increased and then reduced after increasing to the biggest along the flow field as the attack angle increased; For the forepart
of the wing tine, the cold wall heat flux was smaller whether the attack angle increased, which meant that the down dream wing
had no influence on the cold wall heat flux. Meanwhile, the cold wall fluxes on the board near the wing foot increased along with
the increase of the attack angle of the board-wing. That is to say that the interaction area was more close to the wing root. In
addition, the heat flux suddenly decreased and then increased when the total enthalpy was less than 6000 kJ/kg.
© 2014 The Authors. Published by Elsevier Ltd.
Peer-review under responsibility of Chinese Society of Aeronautics and Astronautics (CSAA).
Keywords: Arc wind tunnel; Body- wing; Interaction area; Aero thermodynamic environment
1. Introduction
As an important part of a high speed aerocraft, the wing (rudder) will remarkably change the fluid structure
during flying. In order to effectively control an aerocraft, the flying wing (rudder) would usually be deflected to
*
* Corresponding author. Tel.: +86-10 -68375637; fax: +86-10-68375637.
E-mail address: xukjzit@163.com
1877-7058 © 2014 The Authors. Published by Elsevier Ltd.
Peer-review under responsibility of Chinese Society of Aeronautics and Astronautics (CSAA).
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XU Kao / Procedia Engineering 00 (2014) 000–000
some certain position. Here, the interaction area and even boundary layer separation phenomenon were produced by
the intensive shock wave from the defected wing surface and the boundary layer on the arc board, which makes
great changes for the local pressure and thermal load near the interaction area, will take place. When the local
thermal load increases, the area will undergo the most rigorous aerodynamic heating. The heat fluxes distribution
evaluation near the interactive area will direct influence aero thermodynamic tests and the thermal protection design
for the aerocrafts.
The body-wing interaction area is mainly involved in the interaction area produced by some shock wave and the
flowing boundary layer. When the shock wave enters the boundary layer, the reverse pressure grads will occur after
the air flow, which will lead to boundary layer separation. Boundary layer separation will arose shock wave
separation. Afterward, boundary layer reattaches. Here, reattachment wave occurs. The boundary layer near the
reattachment position becomes thin and the static pressure increases. In this way, the local higher heat fluxes area
come into being.
Presently, almost all studies for body-wing interaction area mainly focus on the two aspects, respectively,
experiments in the shock wind tunnel and numerical calculation. In the year of 1986, young et al[1] experimentally
researched the vertical board-rudder laminar interaction area and found that the interaction area originated at the
foreside of the rudder far away from 6 time diameters when the coming Mach numbers were 3 and 5. Schuricht et
al[2] used flow field display technique to research the board-blunt rudder interaction area and found the similar
results as young’s. LI. Y. L. [3], Li Y. Y.and Li.S.S.[4] respectively researched the influence of the sweepback on the
interaction area of air rudders and found the larger sweepback made the interaction area smaller. Hung [5], Clauss[6],
Schuricht[7] and Fomisison[8] had done much work to research the interaction area on the laminar and turbulent
conditions. However, there were only few studies for the interaction area of the deflexion wing and only Li.Y.Y [9]
researched the influence of the deflexion angle on the static pressure on the board, the heat fluxes on the leading
edges and the wing surface. It is necessary to study the heat flux distribution near the interaction area of the
deflexion wing, which will satisfy the engineering utility.
In this paper, the aero thermodynamic environments were experimentally studied in the arc wind tunnel and some
cold wall heat fluxes on the arc board near the wing foot and on the forepart of the wing were measured and some
regularities were found, which would help to guide the design of thermal protection.
2. Experimental set up
Experiments were conducted in the arc heated wind tunnel attached to China Academy of Aerospace
Aerodynamics（CAAA）. The experimental system included an arc heater, a chamber by use of mixing air, a
nozzle, an experimental cabin and a vacuum system, shown in the fig. 1.
Fig. 1. Experimental system sketch
XU Kao / Procedia Engineering 00 (2014) 000–000
3
At first, some cold air entered the arc heater and be heated. Then the heated air flowed into the chamber to mix
with some cold air until the total enthalpy was required. Subsequently, the mixed air flowed into the nozzle and the
supersonic flow field came in to being at the exit of the nozzle. The board-wing was placed into the supersonic flow
field to simulate the flying conditions in air. Finally, all the flowing air flowed into the vacuum system by the
diffuser and be ejected to the air.
The arc board-wing lied at the exit of the cone-shaped nozzle and the angle between the arc board-wing and the
coming flow was 15degrees, shown in Fig.2.
Arc board-wing
Nozzle
The interaction area
Fig. 2. The relative location between the arc board-wing and the nozzle
Because the board-wing was deflected to the left at 15 degrees facing the flow direction, so the interaction area
lied on the right of the wing foot. Some cold wall heat fluxes were measures near the interaction. The location where
the slug calorimeters were installed was shown in Fig.3. In this Fig，there are totally 10 points to measure the cold
wall heat flux near the interaction area, 6 point among of which were close the wing foot, namely, q11, q12, q13,
q14, q15 and q16. Another three points, which were 20mm away from the point 14, point 15 and point 16, were
q21, q22 and q23. The three points were slightly far away from the wing foot. There was only one point-q0- at
10mm away from the forepart of the wing tine.
In the experiment, the level edge on the front edge of the arc board touched the edge at the exit of the nozzle,
whose exit diameter and throat diameter were respectively Φ150 andΦ30.The arc board was level with the exit. The
windward angle of the leading edge is 14 degrees.
Fig. 3. The testing points near the interaction on the arc board
3. Experimental results and analysis
The experimental results included two parts, namely, the effects of the attack angle on the interaction area and the
effects of the enthalpy on the interaction area. In the part, all the cold wall heat fluxes were dimensionless. The q0 at
some condition was designated as the reference value.
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XU Kao / Procedia Engineering 00 (2014) 000–000
3.1. Effects of the attack angle on the interaction area
The Testing conditions were shown in table 1.
Table1. testing conditions
Mach number
Total temperature(K)
Total pressure(atm)
Attack angle (°)
Reynolds number (/m)
5.3
5000
5.1
3.5, 8 ,14
1.5×105
Fig.4 indicated that the heat fluxes near the interaction area when the attack angle was 3.5°. Here q1x and q2x
respectively denoted q11,q12,…,q16 and q21,q22,q23. According to fig.4, we found the heat fluxes at the wing foot
increased and at the position of 240mm away from the front edge of the arc board, the heat fluxes reached
stabilization, which revealed the interaction area lied at the wing foot of 240mm away from the front edge.
Fig.5 showed the heat fluxes near the interaction area when the attack angle was 8°. As the attack angle
increased, the higher heat fluxes region moved forward and ranged from 186mm to 216mm away from the front
edge. This phenomenon indicated that the interaction moved forward with the increase of the attack angle.
30
18
27
24
15
q1x/q0-3.5°
(q2x)/q0-3.5°
q1x(q2x)/q0
q1x(q2x)/q0
21
12
9
6
18
15
12
9
q1x/q0-8°
(q2x)/q0-8°
6
3
3
0
0
0
40
80
120
160
200
240
280
320
360
0
400
40
80
120
160
200
240
280
320
360
400
L (mm)
L (mm)
Fig. 4. the heat fluxes near the interaction area(3.5° of attack angle)
Fig. 5. the heat fluxes near the interaction area(8° of attack angle)
42
39
36
33
30
q1x(q2x)/q0
27
24
21
q1x/q0-14°
(q2x)/q0-14°
18
15
12
9
6
3
0
0
40
80
120
160
200
240
280
320
360
400
L (mm)
Fig. 6. the heat fluxes near the interaction area(14° of attack angle)
XU Kao / Procedia Engineering 00 (2014) 000–000
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Table 2. testing conditions
Mach number
Total enthalpy(kJ/kg)
Total pressure(atm)
Attack angle (°)
Reynolds number (/m)
6.0, 5.8 ,5.3
3000,6000,10000
3, 4, 5.1
3.5
(1.1 ~1.7)×105
As the attack angle further increased to 14°, the highest heat flux position still at the position of 236mm away
from the front edge, furthermore, the heat fluxes at the wing foot further increased, which revealed that the heat
fluxes on the interaction area increased as the attack angle aggrandized. On the other hand, the heat fluxes on outer
area( q21,q22,q23 in Fig.6) decreased.
By comparison with Fig.4, Fig.5 and Fig.6, we found that the interaction area was further close to the wing foot
and moved forward as the attack angle increased, which was consistent with literature[10]. Meanwhile, the
interaction area would stabilize at some position though the attack angle increased. In addition, the heat flux at the
fore wing tine was nothing changed as the attack angle changed, which meant that the downdream wing had no
influence on the cold wall heat flux.
3.2. Effects of the total enthalpy on the interaction area
The Testing conditions were shown in table 2. Fig.7,Fig.8 and Fig.9 respectively indicated the heat fluxes near
the interaction area when the total enthalpies were 3000kg/kg, 6000kJ/kg and 10000kJ/kg. by comparison of the
three Figures, it was obvious that the increase of enthalpy did not change the position of the interaction area, which
situated at the area of 186mm to 400 mm(the tail) away from the front edge of the arc board when the attack angle
was smaller(here was 3.5°), and only the heat fluxes on the interaction area were in accretion. There was a distinct
deference among the three figures that the heat flux decreased at the position of 186mm away from the front edge,
then increased when the total enthalpies were 3000kJ/kg and 6000kJ/kg. Whether the flow separation occurred
would arouse our interest.
6
5
q1x(q2x)/q0
4
3
2
q1x/q0-3000
(q2x)/q0-3000
1
0
0
40
80
120
160
200
240
280
320
360
400
L (mm)
Fig. 7. the heat fluxes near the interaction area(3000kJ/kg of total enthalpy)
6
5
q1x(q2x)/q0
4
3
2
q1x/q0-6000
(q2x)/q0-6000
1
0
0
40
80
120
160
200
240
280
320
360
400
L (mm)
Fig. 8. the heat fluxes near the interaction area(6000kJ/kg of total enthalpy)
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XU Kao / Procedia Engineering 00 (2014) 000–000
18
q1x(q2x)/q0
15
12
9
6
q1x/q0-10000
(q2x)/q0-10000
3
0
0
40
80
120
160
200
240
280
320
360
400
L (mm)
Fig. 9. the heat fluxes near the interaction area(10000kJ/kg of total enthalpy)
4.Conclusion
Base on the analyses above, we obtain some conclusions:
 The increase of the attack angle would make the interaction area forward and the heat fluxes on the
interaction area fleetly increased;
 The heat flux at the fore wing tine was nothing changed as the attack angle changed;
 The increase of the total enthalpy did not make the interaction forward and only the heat fluxes on the
interaction area were in accretion;
 The heat flux suddenly decreased and then increased. Whether there was flow separation should be further
invested.
References
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