A gas jet impacting a cavity

A gas jet impacting a cavity produces secondary jet stagnation temperature much higher than the stagnation temperature of the primary jet. The heating phenomenon from a gas jet cavity impact is investigated. The heating phenomena in resonance tubes and Hilsch vortex tubes is reported. An end wall temperature increase of 235 C is measured in a resonating cavity. A very small hole at the cavity bottom eliminates resonance and produces a secondary jet stagnation temperature identical to the cavity end wall temperature. A secondary jet stagnation temperature increase of 19 C is obtained in high velocity measurements without resonance. Optimum secondary jet temperatures occur in cavities favorable for a good vortex pattern. Flow smoke visualization experiments verified the occurrence of a strong vortex flow at cavity diameter to jet diameter ratios near 1.5.