Propagation of rarefaction wave accompanying phase change

The transient phase change induced by propagation of rarefaction wave is elucidated by measuring the pressure response. Experiments are conducted on a vertical shock tube fulled with refrigerant R-11. Pressure responses are measured at three different points along the tube, and the time lag of the phase change is detected from laser cut-off signals. In the absence of bubble nuclei, the phase change is found not to occur for the first-coming rarefaction wave. (author)