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ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

NUMERICAL ANALYSIS AND OPTIMIZATION OF SUPERSONIC MIXING WITH INSTABILITY EXCITATION

Get access (open in a dialog) DOI: 10.1615/IHTC16.hte.022214
pages 5425-5434

Sinopsis

The mixing between two streams supersonic flow takes place only in thin shear layers because of low fluctuation energy in high-speed flows. Most of mixing optimizing strategies will influence the dynamics of supersonic flow and produce undesirable shocks. An instability excitation is introduced to enhance the mixing processes of a jet issuing into a supersonic region. The numerical simulation is performed on a jet issuing into a nozzle flow configuration. The jet is excited, with respect to excitation amplitude and frequency: the excited jet instability mechanism is proposed and the jet flow is input into the primary flow as a function of time. When the two fluids are mixed, interacting large-scale coherent structures are developed as a consequence of the flow instability and a large size "temporal-spatial" mixing layer is obtained. The extent of mixing is measured by the mixedness parameter and in the optimized mixed flow this parameter has increased 2.7 times of the original unexcited flow of the setup depicted in the paper. Because there is no pressure disturbance introduced by using instability excitation, the supersonic flow uniformity is retained. Therefore, the instability can be applied in the supersonic region to optimize the mixing processes.