Prediction of droplet size and velocity distribution based on maximum entropy formulation by nonlinear instability analysis of liquid sheet spray and turbulent of nozzle flow

Abstract

In this research, it is attempted to determine the diameter and velocity distribution according to the flow characteristics of the upstream and without needing experimental measurements.Firstly, Fluent software has been used to simulate the turbulent flow of inside nozzle by k-? model to obtain the nozzle turbulence energy at the nozzle outlet. Then, nonlinear growth rate analysis of instability is used to determine spray breakup length and the frequency of maximum instability and the mean diameter of primary breakup. Four equation maximum entropy model has been developed according to the inlet of upstream flow. Subsequently, the terms of momentum source as well as the energy of maximum entropy model has been determined using the results of simulated nozzle turbulence flow and instability analysis. In the following, first the results of maximum entropy model have been evaluated with the experimental input and then determined with upstream input. The obtained results which have been compared with experimental tests show well agreement.

Keywords

• k-ε simulation
• diameter distribution
• non-linear instability analysis
• maximum entropy