Validation of an analytical model for an unsteady planar jet with self-sustained oscillations

Flow field in an oscillatory plane jet with self-sustained oscillations was studied by using a corrected similarity solution and the an analytical unsteady flow model was validated via hot wire measurements. A decomposition approach was used to identify the contribution due to the deterministic flow field oscillations and stochastic turbulent fluctuations. To realize this decomposition, an accurate, efficient hot wire technique based on a crossed wire sensor was implemented. The governing equations were derived for flows containing deterministic oscillations of fixed frequency. Both experiments and analysis prove that oscillation stresses contribute to the transport process and that the double velocity correlations obtained from oscillation fluctuations and turbulent fluctuations are negligible compared to Reynolds and oscillation stresses. This feature simplifies the equations and the analysis significantly. The present corrected similarity solution predicts planar oscillatory jet flow quite well. The instantaneous deterministic part of the flow field can be calculated with reasonable accuracy. Mean velocity, oscillation stresses, oscillation kinetic energy predictions from the new analytical model developed in this study are in very close agreement with the measured data.