Experimental evidence for Plotkin model of shock unsteadiness in separated flow

Jonathan Poggie, Alexander J. Smits

Research output: Contribution to journalArticlepeer-review

33 Scopus citations


Experimental evidence is presented in support of a model of separation shock unsteadiness developed by Plotkin [AIAA J. 13, 1036 (1975)]. Under this model, the position of the separation shock follows linearly damped Brownian motion. The model describes the manner in which relatively broad-band perturbations in the incoming flow lead to relatively low-frequency motion of the separation shock. Close agreement was found between the predictions of the model and the autospectra and autocorrelations of wall pressure fluctuations and shock position fluctuations for several blunt fin flows at Mach 3 and Mach 5. Given the similarity of the power spectra of wall-pressure fluctuations for a variety of separated, supersonic flows, this description may have broad applicability.

Original languageEnglish (US)
Article number018107
Pages (from-to)018107-018107-4
JournalPhysics of Fluids
Issue number1
StatePublished - Jan 2005

All Science Journal Classification (ASJC) codes

  • Computational Mechanics
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering
  • Fluid Flow and Transfer Processes


Dive into the research topics of 'Experimental evidence for Plotkin model of shock unsteadiness in separated flow'. Together they form a unique fingerprint.

Cite this