Radiofrequency plasma stabilization of a low-Reynolds-number channel flow Academic Article uri icon

abstract

  • AbstractThe effects of plasma heating and thermal non-equilibrium on the statistical properties of a low-Reynolds-number ($Re_{ au } = 49$) turbulent channel flow were experimentally quantified using particle image velocimetry, two-line planar laser-induced fluorescence, coherent anti-Stokes Raman spectroscopy and emission spectroscopy. Tests were conducted at two radiofrequency plasma settings. The nitrogen, in air, was vibrationally excited to $T_{vib} sim 1240 mathrm{K}$ and 1550K for 150W and 300W plasma settings, respectively, while the vibrational temperature of the oxygen and the rotational/translational temperatures of all species remained near room temperature. The peak axial turbulence intensities in the shear layers were reduced by 15 and 30% in moving across the plasma for the 150 and 300W cases, respectively. The plasma did not alter the transverse intensities. The Reynolds shear stresses were reduced by 30 and 50% for the 150 and 300W cases. The corresponding Reynolds shear stress correlation coefficient was also reduced, which indicates that the large-scale structures were diminished. Finally, the plasma enhanced the turbulence decay in the zero-shear regions, where the power law decay $t^{-1/n}$ exponential factor $n$ decreased from1.0 to0.8.

published proceedings

  • JOURNAL OF FLUID MECHANICS

author list (cited authors)

  • Fuller, T. J., Hsu, A. G., Sanchez-Gonzalez, R., Dean, J. C., North, S. W., & Bowersox, R.

complete list of authors

  • Fuller, Timothy J||Hsu, Andrea G||Sanchez-Gonzalez, Rodrigo||Dean, Jacob C||North, Simon W||Bowersox, Rodney DW

publication date

  • January 1, 2014 11:11 AM