Informatics Publishing Limited

T. Sivamurugan ¹, P. Anoop ¹, S. L. N. Desikan ¹

Affiliations
1 Aeronautics Entity, Vikram Sarabhai Space Centre, Indian Space Research Organisation, Thiruvananthapuram 695 022, IN

Abstract

Reusable Launch Vehicle-Technology Demonstrator (RLV-TD) experiences severe thermal environment during its ascent as well as re-entry into the atmospheric regime. Structures should be designed to withstand this thermal load. Thermal environments were estimated for RLV-TD and depending on the peak heat flux and heat load, hot structure design for nose cap, wing, vertical tail and control surfaces was developed. Thermal protection system (TPS) using silica tile and flexible insulation was designed to protect the windward and leeward regions respectively. It is essential to verify and establish the design and also physically corroborate the actual thermal performance. Besides the design, the hot structures and TPS functionality as a system has to be qualified and thereby yield full confidence on the total performance during flight. To qualify the hot structures and TPS, various qualification tests were undertaken. The demonstration of their fly-ability and qualification under the combined effect of structural and thermal load was carried out successfully for all structures. This article provides details of aerothermal design of RLVTD and various qualification tests carried out. Comparison of the estimated structure temperatures with measured temperatures in flight shows the robustness of the design methodologies adopted.

Keywords

Heat Flux, Reusable Launch Vehicle, Temperature, Thermal Protection System.

Full Text

   

S. Somanath ¹, S. Unnikrishnan Nair ², T. Sivamurugan ¹, S. L. N. Desikan ¹

Affiliations
1 Vikram Sarabhai Space Centre, Indian Space Research Organisation, Thiruvananthapuram 695 022, IN
2 Human Space Flight Centre, Indian Space Research Organisation, Bengaluru 560 054, IN

Abstract

As a prologue to the Gaganyaan project, ISRO successfully test fired one of the critical and essential technologies for human space flight, i.e. Crew Escape System (CES) Pad Abort Test on 5 July 2018. This is a strategically important flight as a part of various qualification tests that ensures emergency escape measure to quickly pull the Crew Module (CM) along with the astronauts to a safe distance from the launch vehicle in case of any eventuality. CES along with CM weighing of 12.6 tonnes lifted-off at 07.00 h from the Sounding Rocket Complex Launch Pad, Sriharikota. The vehicle was taken to an altitude of 3 km using a specially developed solid motor with multiple reverse flow and scarfed nozzles with 10 g acceleration. Around 330 sensors on-board were used to measure its performance. The data obtained ensured that the adopted design philosophy and approaches such as CM reorientation, aerodynamic data with jet-on environment, mission sequences, performance of special solid motors, deceleration system, etc. were in order. This provides more confidence to progress to the next level of demonstration as a part of Gaganyaan.

Keywords

Crew Escape System, Crew Module, Flight Performance, Pad Abort.

Full Text

   

R. Saravanan ¹, J. A. Tennyson ¹, S. L. N. Desikan ¹, M. M. Patil ², R. Kalimuthu ³, Surendranath ⁴

Affiliations
1 Wind Tunnel Data Division, and Synthesis Group, Vikram Sarabhai Space Centre, Thiruvananthapuram 695 022, IN
2 Aerodynamic Design and Synthesis Group, Vikram Sarabhai Space Centre, Thiruvananthapuram 695 022, IN
3 Cryo and Semicryo Subsystem Test Facilities, ISRO Propulsion Research Complex, Mahendragiri 627 133, IN
4 Department of Aerospace Engineering, Indian Institute of Science, Bengaluru 560 012, IN

Abstract

Aerodynamic characteristics of Crew Module (CM) during its separation from the Crew Escape System (CES) are essential to carry out separation dynamics analysis for confirming collision-free separation. As CM is at the base of CES, it has to clear the complex wake flow that prevails in the aft region. A 1 : 10-scale wind tunnel model is tested at 45 m/s freestream velocity in Indian Institute of Science, Bengaluru lowspeed tunnel. The interaction of CM with the base flows is studied for different attitude conditions in terms angle of attack, longitudinal and lateral movements. Results indicate that CM is recovered from forebody influence beyond X/D = 2, and it experiences reverse flow till it moves to X/D = 1.4D. Stability characteristics of CM are also analysed.

Keywords

Aerodynamics, Crew Models, Crew Escape System, Stability Characteristics, Wind Tunnel.

Full Text