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Formation and hot flow duration of micro shock flows

The key issue of the present work is the propagation of micro shock flows. In particular, this work focuses on the shock formation and hot flow duration (test time). The shock formation process involving trailing compression waves is experimentally well resolved. In contrast to experiments in macroscopic shock tubes (above 1 mm hydraulic diameter), the hot flow duration at a microscale cannot be described by the conventional “leaky piston” model or any other currently available models, especially, when the propagation length is more than one hundred times the diameter, namely, a length that has never been investigated before. Navier-Stokes computations show that the numerical and the experimental results have the same trend when the distance increases along the tube. Consequently the simulations indicate benefits when compared to the “leaky piston” model.