K. Ramachandra, S. Bhardwaj, J. N. Murugan, R. Sriram
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Study of unsteadiness due to 3-D shock–boundary layer interaction in flow over a square-faced protuberance
The dynamics of shock-induced unsteady separated flow past a three-dimensional square-faced protuberance are investigated through wind tunnel experiments. Time-resolved schlieren imaging and unsteady surface pressure measurements are the diagnostics employed. Dynamic mode decomposition (DMD) of schlieren snapshots and analysis of spectrum and correlations in pressure data are used to characterize and resolve the flow physics. The mean shock foot in the centreline is found to exhibit a Strouhal number of around 0.01, which is also the order of magnitude of the Strouhal numbers reported in the literature for two-dimensional shock–boundary layer interactions. The wall pressure spectra, in general, shift towards lower frequencies as one moves away (spanwise) from the centreline with some variation in the nature of peaks. The cross-correlation analysis depicts the strong dependence of the mean shock oscillations and the plateau pressure region, and disturbances are found to travel upstream from inside the separation bubble. Good coherence is observed between the spanwise mean shock foot locations till a Strouhal number of about 0.015 indicating that the three-dimensional shock foot largely moves to-and-fro in a coherent fashion.
期刊介绍:
Shock Waves provides a forum for presenting and discussing new results in all fields where shock and detonation phenomena play a role. The journal addresses physicists, engineers and applied mathematicians working on theoretical, experimental or numerical issues, including diagnostics and flow visualization.
The research fields considered include, but are not limited to, aero- and gas dynamics, acoustics, physical chemistry, condensed matter and plasmas, with applications encompassing materials sciences, space sciences, geosciences, life sciences and medicine.
Of particular interest are contributions which provide insights into fundamental aspects of the techniques that are relevant to more than one specific research community.
The journal publishes scholarly research papers, invited review articles and short notes, as well as comments on papers already published in this journal. Occasionally concise meeting reports of interest to the Shock Waves community are published.