ANALYSIS OF THERMO-ACOUSTIC STREAMING BY CFD SIMULATION

摘要

To develop a new numerical model of thermo-acoustic streaming using time-averaged quantity, the streaming is analyzed with direct numerical simulation (DNS). We have confirmed that acoustic radiation force that acts like buoyancy is the key to build the time average model. The thermo-acoustic streaming is a new type of convection that has been discovered experimentally under micro-gravity in our past work. The convection occurs when a droplet burns in a standing sound wave. When the droplet is placed between a node and an anti-node, the flame is flown in one direction. The flow is the "thermo-acoustic streaming". The detailed data on the flow field of the streaming does not exist so far. The fields are analyzed with DNS here. The DNS requires a lot of computational time. A new numerical model with time-averaged quantity is favored. It has been confirmed that the governing equation of DNS can reproduce the thermo-acoustic streaming. The time average model is to be developed based on the equation. The numerical data are compared with the experimental data, and we have clarified the mechanism of the streaming.