Design, fabrication and experimental investigation of liquid nitrogen based thermal chamber to achieve desired thermal gradients for aerospace/missile testing applications

In the present work, an environmental chamber is chosen to study the feasibility for its conversion to a better high thermal gradient system keeping in view the present and future demands of climatic tests of the advanced missile systems/sub-systems. Mathematical calculations have also been made to achieve desirable steep thermal gradients by controlling the liquid nitrogen flow rates even without using any other cooling system like vapour compression based system which involves regular maintenance, bulky and noisy mechanisms. With this, a liquid nitrogen based test setup has been designed, fabricated and integrated with existing thermal chamber to achieve variable temperature gradients of the order of 15°C per minute. The mathematical calculations have been duly validated by experimental work. This newly designed system can be directly used for climatic testing of aerospace components, missile systems and warheads/explosives at desired thermal gradients.