Chapter 58 - Experimental investigation on the performances of gas flow in oscillating tube

Abstract

This chapter follows an experimental investigation on the performances of gas flow in oscillating tubes. The gas oscillating tubes are the key part of the gas wave refrigerator for heat change with environment. The flow progress of the gas in the oscillating tubes is very complex. The work medium is compressed air supplied by the oilless air compressor. The oscillating tube with shock wave damping tank and circumfluence tube have been performed with this apparatus. The research shows that the reflected shock wave is the main factor which influences the refrigerating effect. Shock wave is reflected on rigid wall by shock wave, and expansion wave is reflected on free surface. A stronger shock wave is formed when two shock waves interact, but the intensity weakens when it acted by expansion wave. The shock waves in oscillating tube can be eliminated or weaken by increasing friction of the wall of the tube, increasing damp in hot end, reducing the energy of the gas, or acting by expansion wave. The temperature drops and isentropic refrigerating efficiency of the oscillating tube can be increased by coupling with shock wave damping tank or circumfluence tube.