Abstract
Internal gravity waves with fundamental frequency components of 1.2,1.8,3.0Hz were spontaneously generated in a strongly stably-stratified mixing layer. The spatial structure of internal gravity waves was experimentally examined to clarify the mechanism of occurrence of counter-gradient heat flux. Multi-point simultaneous measurement was conducted on the spatial structure by using a multi-channel high precision thermo-anemometer system. Transverse spatial correlation between temperature fluctuations was enhanced, as the internal gravity waves grew downstream, which characterizes the development of vertical structure of the wave motion. Counter-gradient heat flux was confirmed to occur at the break down of the wave front of the internal gravity waves.
