Design of heated flow wind tunnel facility for testing small size ramjet engine combustors
Panikulam, John Paul
Date of Issue2014
School of Mechanical and Aerospace Engineering
This report documents the research studies on the design of a 'high speed heated flow wind tunnel facility', to test a 'Trapped Vortex Concept' (TVC) combustor of a ramjet engine, designed for the DSO National Laboratories, Singapore. The ramjet is to operate at flight speeds of Mach 2.5 to 4.0. A direct-connect wind tunnel is designed in order to test the ramjet combustor. Combustion testing can be carried out when the wind tunnel is running. Pebble bed type heaters are used to heat the air to the required operating conditions. A thermodynamic cycle analysis was performed on the ramjet engine to estimate air properties at the combustor inlet. The calculations revealed that even though the flight is supersonic, the inlet condition to combustor was still subsonic (Mach 0.70 and 0.80 corresponding to flight speed of Mach 2.5 and 4.0 respectively). Hence the wind tunnel was designed to run at subsonic speeds. A wind tunnel design was developed to deliver the estimated air properties corresponding to maximum operating conditions (Mach 0.80), at the combustor inlet. Specifications for machinery such as compressor, air storage tank, pebble bed heater, etc were estimated such as to provide the calculated operating conditions of the wind tunnel. Finally pressure drop calculations were performed on the pipelines and fittings for pipe line sizing of the facility.