Viscous-inviscid analysis of dual-jet ejectors

Abstract

A viscous-invisc id interaction method is developed to predict the performance of two-dimension al, incompressible flow ejectors that use two primary jets. The flowfield is subdivided into a viscous region that contains the turbulent jets and an inviscid region that contains the ambient fluid drawn into the device. The inviscid flow is modeled with a higher-order panel method, and an integral method is used for the description of the viscous part. The strong viscous-inviscid interaction between the jets and the ambient fluid is simulated in an iterative process where the two regions influence each other en route to a converged solution. This formulation retains much of the essential physics of the problem but at the same time requires only a small amount of computing effort. The model is applied to a parametric study that illustrates the connection between the details of the ejector geometry and the level of thrust augmentation. The advantages of a dual-jet configuration are assessed through a comparison of the present results with similar calculations for an otherwise identical single-jet ejector.