The effects of compressibility on the planar mixing layer are investigated by means of visualization and statistical analysis of the flowfield quantities computed using three-dimensional temporally evolving inviscid simulations. The levels of compressibility studied range from relative Mach numbers of Mr= 0.2−2.4. The objectives of this research are to identify large-scale structures present in the mixing layer at different levels of compressibility as well as to examine the statistical description of the flowfield, in order to gain understanding of the physical entrainment and mixing processes. Three-dimensional simulation visualizations of both the passive scalar and pressure fields show the nature of the large-scale structure present in the planar mixing layer to change from nearly two dimensional and spanwise at low compressibility to highly three dimensional and oblique at increased compressibility. Statistical analysis of the flowfield quantities shows that the shear layer width, Reynolds shear stress, and transverse turbulence intensity decrease with increasing compressibility levels, whereas the streamwise turbulence intensity remains nearly constant and the spanwise turbulence intensity increases. These statistics support the increasingly three-dimensional nature of the large-scale motion of the mixing layer with increasing Mr.
ASJC Scopus subject areas
- Aerospace Engineering