Mach number effects on entrainment and mixing in supersonic planar turbulent wakes

Masaki Nakagawa, Werner Dahm

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations

Abstract

Results are presented from an experimental investigation of Mach number effects on entrainment and mixing in a supersonic, planar, turbulent, bluff-body wake formed by a two-dimensional slot jet nozzle aligned with two different Mach number free stream produced by Mach 2.0 and Mach 3.0 nozzles. Planar laser Mie scattering (PLMS) and shadowgraph imaging are combined with pitot and static pressure measurements to examine the mean flow scaling laws and the instantaneous structure of the flow fields. Results for both flows show classical vortex street-like large-scale structures in the wake far field, where the relative Mach numbers have decreased to clearly subsonic values, and the growth rates and velocity decays in the near field followed the characteristic (δ/u>) - (x/u)1/2 and (u/U) ~ (x/u)~l/2 scaling of incompressible planar turbulent wakes. These scaling constants agreed with values for forced incompressible wakes for the Mach 2 case, while those for the Mach 3 case agreed with unforced values, presumably due to the potential existence of "subsonic path". Moreover the interaction of reflected expansion waves with the large-scale vortical structures in the wake appeared to increase the growth rate drastically for both flows which may be attributable to its "self-exited forcing mechanism".

Original languageEnglish (US)
Title of host publication38th Aerospace Sciences Meeting and Exhibit
StatePublished - 2000
Externally publishedYes
Event38th Aerospace Sciences Meeting and Exhibit 2000 - Reno, NV, United States
Duration: Jan 10 2000Jan 13 2000

Other

Other38th Aerospace Sciences Meeting and Exhibit 2000
CountryUnited States
CityReno, NV
Period1/10/001/13/00

ASJC Scopus subject areas

  • Space and Planetary Science
  • Aerospace Engineering

Fingerprint Dive into the research topics of 'Mach number effects on entrainment and mixing in supersonic planar turbulent wakes'. Together they form a unique fingerprint.

  • Cite this

    Nakagawa, M., & Dahm, W. (2000). Mach number effects on entrainment and mixing in supersonic planar turbulent wakes. In 38th Aerospace Sciences Meeting and Exhibit