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A 1:8 scale model of isolated inlet (air-intake) of Hypersonic Technology Demonstrator Vehicle
(HSTDV) was tested at Mach 3.6 in 340 mm diameter enclosed free jet Supersonic Blow down Wind tunnel at
DRDL, Hyderabad. The test Reynolds number is 65 million per meter and stagnation temperature is 300K.
Tests were conducted using replaceable cowls of different lengths at different cowl hinge line locations to study the starting characteristics of the intake. To simulate the flight condition, the cowl is initially kept in closed position and then opened to the desired angle using a hydraulic actuator. Experiment consists of internal surface pressure measurement and flow visualization by shadowgraphs. Results indicate that shifting of cowl hinge line rearward improved the starting characteristics significantly.
Key Words : Contraction ratio, cowl hinge line location, started and un-started intake
CR
P
M
= Contraction Ratio, (ratio of cross-sectional
areas of throat and intake entry)
= Pressure
= Mach number
L e
= Horizontal distance between leading edge
of bottom wall and leading edge of cowl
L h
= Horizontal distance between leading edge
of bottom wall and cowl hinge line
 cowl
= Angle between cowl bottom surface and
free stream, degrees
Hypersonic Technology Demonstrator Vehicle
(HSTDV) is being developed by DRDL to prove the high-end technologies such as scramjet propulsion, high temperature materials and high temperature aerothermodynamics at hypersonic speeds.
A 1:8 scale model is chosen from the consideration of blockage to the flow. Blockage area of the model and its support strut is about 8% of test section area. The model is of modular construction and has a box type structure with constant width of
6.4h, where ‘h’ is the isolator height. The model consists of four sections: flat plate with side fences, contraction, constant area and divergent portion.
A number of static pressure ports of 1 mm diameter were located along the centre line of the bottom wall, top wall and side wall. Polyurethane tubes from each of the pressure ports were connected to scannivalve located inside the tunnel plenum chamber and a few were connected in parallel to the pressure transducers.
In Eqn. (1), …
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0
F ( r ,
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(1)
Referencing a literature use number citations on the line, in square brackets, multiple references are each numbered with separate brackets, [1] [2]. Do not use “Ref.” or “reference” except at the beginning of a sentence: “Reference [3] shows ....”
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Scientists, Aero Test Facilities Division, Directorate of Aerodynamics
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Technical Officer, Aero Test Facilities Division,
Directorate of Aerodynamics
© A Satyanarayana, Ch Srikanth, J Chandrasekhar and S V Ramana
Surface pressure distribution over the bottom wall of the intake is shown in Fig. 4a for intake with cowl 1. The pressure data of the intake with cowl 1 for cowl opening angle of 8º (corresponding CR =
0.441) shows that the pressure distribution up to cowl entry is same and is equivalent to free stream static pressure.
Surface pressure distribution on the bottom wall of the intake with cowl 2 is also shown in Fig. 4a for cowl opening angle of 13.75º. For cowl 1 and cowl 2,

2 Paper Title the leading edge location of cowls is same for both the intakes (11h).
The summary of the test results is given in
Table II. From the table, it is observed that shifting of the hinge line location rearward and using longer cowl improves the pressure recovery and the mass flow through the intake.
A 1:8 scale air-intake model of Hypersonic
Technology Demonstrator Vehicle was tested in
340mm diameter enclosed free jet supersonic wind tunnel at Mach 3.6.
The authors express thanks
Shri. H. Govindarajan, Technology Director, DOAD and HSTDV Project Team for useful discussions and suggestions. The authors are also thankful to ATF team for providing all the necessary support during the test program.
[1] A. Satyanarayana, et al “Experimental
Investigation of Isolated Hypersonic Inlet”,
Proceedings of SAROD, Dec 2005.
[2] Ch. Srikanth, et al “Starting characteristics of isolated air-intake of a Hypersonic Technology
Demonstrator Vehicle” p-126, NCAE 2008.
[3]
E.L. Goldsmith, J. Seddon, “Practical Intake
Aerodynamic Design”, Blackwell scientific publications, 1993.
Table I: Cowl details
Config. Cowl 1 Cowl 2 Cowl 3
Lh 16.7h 19 h 19 h
Le 11 h 11 h 12.1 h
Table 2: Summary of Test Results
Cowl Configuration Cowl 1 Cowl 2 Cowl 3
Hinge location, L h
16.7 h 19 h 19h
Cowl length 5.7 h 8h 6.9h
Pressure recovery 7 10 8
Fig. 3a: Effect of hinge line location on bottom
Fig. 3b: Effect of hinge line location on side wall pressure distribution
1. Dr. A. Satyanarayana is postgraduate in Aero from
IIT Madras and working in the field of wind tunnel testing in DRDL as Scientist-F.
Brief profile (5-6 Lines) with photograph of author (Maximum of three).
Fig. 1: Configuration of Hypersonic Technology
Demonstrator Vehicle