In a bid to carry out better research in the area of rocket nozzle, Indian Space Research Organisation has established Nozzle Testing Laboratories at Vikram Sarabhai Space Centre in Thiruvananthapuram. The Nozzle Testing laboratories ( NTL ) that were inaugurated recently by ISRO Chairman, are “unique” facilities established for the first time in the country towards carrying out advanced R&D in the area of rocket nozzle, ISRO said. Stating that performance improvement in propulsion systems is essential towards achieving cost effective launch vehicles, the space agency said apart from propellant energetics, the nozzle plays a vital role in improving propulsion system performance. It said by improving performance of existing nozzles and developing new nozzle concepts, which can operate at both low and high altitude regimes, it is possible to obtain significant gains in the delivered specific impulse of rockets. ISRO said the NTL has the capability to cater to a wide range of studies related to nozzles such as contour optimisation for large AR (Area Ratio) nozzles, flow separation, techniques for flow separation control, nozzle wall heat transfer, among others. The NTL consists of a Nitrogen gas generation and storage system, a graphite cored induction heater (for heating nitrogen), a test chamber, a diffuser system and heat exchanger, coolant system and power supply systems. For nozzle performance evaluation, heated nitrogen gas is allowed to expand in nozzles kept in the test chamber having simulated altitude pressure, ISRO said. Noting that gaseous nitrogen admitted to the storage heater from the top exits the heater at the required temperature, it said the facility utilises fast response pressure transducers and instrumentation to study nozzle phenomena. Nozzles up to Area Ratio (AR) 300 and more can be tested in the facility.