Steady Circulation Generated From Oscillating Flow Through a Hollow Cone at the Exit of a Pipe

A numerical approach to optimizing heat removal from a standing wave thermoacoustic engine by generating steady circulation at the outlet is described. The open-ended standing wave engine makes use of a hollow cone placed opening outwards and flush with the open end of the engine. Parallel paths within and without the cone create asymmetric minor losses. These are designed to induce circulation and heat removal. If successful, this will eliminate the need of a cold heat exchanger. The numerical models make use of the commercial RANS numerical solver FLUENT. Orders of magnitude increase in heat flux out of the engine’s open tube as compared to an engine without a cone are demonstrated. Three cones are evaluated at a range of flow parameters. Performance is found to be a strong function of the displacement amplitude compared to the engine diameter. In addition, these results are compared to an experiment that provides velocity data.