Evaluation of local turbulent energy dissipation rate using PIV in jet loop reactor

Abstract

In the present work, experimental analysis has been carried out for jet loop reactors to investigate the mean and turbulence parameters. Measurements have been made using particle image velocimetry (PIV), laser Doppler velocimetry (LDV), and hot film anemometry (HFA). The major aim of this work is to evaluate the local value of turbulent dissipation rate (ε) using PIV. LDV has been used as a benchmark for analyzing the mean flow quantities, while HFA has been mainly used for the evaluation of energy spectra. Thus, the relative strength of these instruments was harnessed for better understanding of the flow pattern. A method has been proposed for the evaluation of ε from the experimental data from PIV and HFA based on structure function relationships and 3D energy spectrum. Overall energy balance has been satisfied implicitly to make the method of ε estimation more robust. As an application, the values of ε obtained from the CFD predictions (Large eddy simulations) have been compared with that of the experimental values showing opportunity for improved design of turbulence based on local ε variations.