Plif temperature and velocity distributions in laminar hypersonic flat-plate flow

Abstract

Rotational temperature and velocity distributions have been measured across a hypersonic laminar flat-plate boundary layer, using planar laser-induced fluorescence. The measurements are compared to a finite-volume computation and a first-order boundary layer computation, assuming local similarity. Both computations produced similar temperature distributions and nearly identical velocity distributions. The disagreement between calculations is ascribed to the similarity solution not accounting for leading-edge displacement effects. The velocity measurements agreed to within the measurement uncertainty of 2 % with both calculated distributions. The peak measured temperature was 200 K lower than the computed values. This discrepancy is tentatively ascribed to vibrational relaxation in the boundary layer.

Application of planar laser-induced fluorescence measurement techniques to study the heat transfer characteristics of parallel-plate heat exchangers in thermoacoustic devices

“…This uncertainty is congruent with literature data concerned with LIF: for example, an uncertainty of 1.8% at 300 K was estimated by Kearney et al in Rayleigh-Benard convection [40]. An uncertainty of 2.4% at around 350 K and 4.5% at around 1000 K was obtained in a laminar hypersonic flow [57] and 10% between 300 K and 3000 K in shock tunnel flows [58].…”