Thermoacoustic Effects in H-S Tubes

Abstract

The thermal effects produced by air column oscillations in resonance tubes driven by a piston, or in Hartmann-Sprenger (H-S) tubes excited by an air jet have interested many researchers. The effects show not only heating of the tube wall near the closed end in both tubes, but also cooling at the section of pressure nodes in the resonance tube. The heating and cooling effect in the resonance tube is explained by energy balance, considering thermoacoustic streaming. The experimental investigations o thermal effects i higher mode oscillations of single-step H-S tubes show that the wall temperature is maximum at the section of velocity nodes and minimum at pressure nodes. It can be explained by the thermoacoustic effect. In the present report, the thermoacoustic effect produced by aircolumn oscillation in a H-S tube separated into two cavities by an orifice is investigated and compared with phenomena in the resonance tube.