Abstract:

The three dimensional body fitted grid is used. The grids near the boundaries are dense and orthogonal. The whole field of the domain is calculated. In order to avoid the divergence as the non orthogonality of the lobe, the Chen Kim modified k ε  model of turbulence and the co located grid, SIMPLEC, are used in the numerical analysis of the mixing flow of the lobed ejector with a double wall diffuser by using the great viscosity for the lobe. The results show that the air is ejected into the double wall section to form the cooling flow, the annular like flow generated along from the lobe enhances the mixing of the primary and secondary flows and the velocity is well distributed. The maximum error between the numerical and the experimental data under the condition relative to the primary speed is about 21.65% at the position of 52mm from the lobe in the mixing section.

Key words: computational fluid mechanics, lobed-mixing, double-wall diffuser, eject or, turbulence, infr ar edra diat ion