SPRAY EVAPORATION IN TURBULENT-FLOW - NUMERICAL-CALCULATIONS AND DETAILED EXPERIMENTS BY PHASE-DOPPLER ANEMOMETRY

The present paper concerns experiments and numerical calculations of a n isopropyl-alcohol spray evaporating in a co-flowing turbulent heated air flow. The measurements provided detailed inlet and boundary condi tions for the numerical calculations and allowed the validation of the numerical method and models. Phase-Doppler anemometry was used in ord er to obtain the spatial change of the droplet size distribution and t he correlation between droplet size and velocity throughout the flow f ield. Additionally, a reliable method based on the detection of the si gnal amplitudes was applied to determine the droplet mass flux. By int egration of the droplet mass flux profiles, the global evaporation rat es could be determined for different flow conditions. Numerical calcul ations of the evaporating spray were performed by the Eulerian/Lagrang ian approach. The modelling of droplet evaporation is briefly reviewed prior to the description of the applied numerical models and methods. Calculations for a single phase flow showed good agreement with the e xperiments. Also for all of the droplet phase properties reasonable ag reement with the experiments could be achieved and the global evaporat ion rates agreed well with the measurements.