مدلسازي اسپري مايع و مطالعات پارامتريك آن در جريان دوفازي محفظه احتراق

Parametric Study and Modeling of Liquid Spray in Two-Phase Flow Combustion Chamber

The rate of penetration and evaporation of spray in combustion chamber plays an important role in engine efficiency. A parametric study has been conducted to investigate the influence of several parameters on the penetration rate and increase of spray evaporation in a two-phase flow. The most influential parameters have been taken into consideration. Those include: the effect of Sauter mean diameter (SMD) on the total evaporated mass and spray penetration in the combustion chamber, the effect of fuel droplets on the flow field inside the chamber. Moreover, the effect of the number of droplets entering the chamber in a time step on the rate of evaporation and the effect of presence of fuel droplets on turbulent intensity and its dispersion has been studied The interconnection between gas and liquid phases has also been investigated. This has been done by considering the effects of initial chamber pressure and temperature on the structure and penetration rate of spray and the effect of turbulence intensity and dispersion on spray behavior. In this paper, a discrete droplet model (DDM) is used to model the spray flow, a Rietz-Diwakar model is used to study the break up of droplets. A standard model is applied to the turbulent flow and a finite valume scheme together with a PISO algorithm is used to solve the governing equations. The results of the current research are compared with the results obtained by using the KIYA computer code and with the experimental results. It is shown that agreement among current results with the experimental and those by the KIVA code is acceptable.