Rusly, E, Lu Aye, Charters, WWS, Ooi, A & Pianthong, K. 2002 'Ejector CFD modelling with real gas model', 16th Conference of the Mechanical Engineering Network Thailand (ME-NETT), 14-16 October 2002, Phuket, pp. 150-155.
Abstract
Ejector analysis is often carried out in one-dimensional approach. Although this method is simple and reasonably accurate in some cases, its limitations have caused development in ejector research a serious stagnation.
CFD analysis allows solutions of non-linear equations resulted from the coupling of turbulence, viscous heating with the energy and momentum equations, interaction between shock and boundary layers that is impossible to model in one-dimensional analysis. Computer resources and iteration time often preclude this type of approach especially when refrigerants with their real gas models and highly dense grid structure are modelled. In this paper, we want to overcome this obstacle by modelling ejector using real gas model with reasonably fine grid structure and solving the flow field with faster parallel computers. Our aim is to get solutions for the ejector model with clarity of all the flow phenomena happening inside it. From the results, supersonic flow exiting from the nozzle entrains the secondary flow with a resultant supersonic mixing. A shock occurs in the constant area duct to bring pressure to condenser pressure at diffuser exit. It is shown an ejector with R245fa fed with generator temperature of 80 C, condenser and evaporator temperatures of 40 and 25 C, respectively has flow characteristics similar to those of typical ejector at design conditions.