Research On Infrared Suppression Of Marine Exhaust Ejector

The exhaust ejector is an important component of the gas exhaust system, whichproduces high speed mainstream of air inhaling the lower speed outside air.The constant process of mixing between the two streams of air can decrease the speedand temperature of the mainstream air flow, through which the effect of infrared suppressionis achieved. With the modern military demand for infrared reduction increasing, the researchon the characteristics of exhaust ejectors has become the focus of attention. There are severalcommon types of ejectors, such as cylinder type, piling type, lobed-mixing type, et al. As theapplication of numerical simulation technology becoming wider and deeper, the appropriatemethod of the combination of the algorithms for each type of ejectors plays an important roleto improve the accuracy of simulation. This paper uses orthogonal test method to investigatethe appropriate algorithm combination respectively for piling type and lobed-mixing exhaustejector. The following work has been done to discover the structural influence on theperformance of lobed-mixing ejector and characteristics of piling type ejectors:1. The orthogonal test method is employed to determine the most appropriate options forthe two types of ejectors among the algorithm combinations involving turbulence model,pressure-velocity coupling algorithm, discretization method and pressure interpolation. Thesefactors are sequenced according to their influence on the simulative results.2. A series of lobed-mixing exhaust ejectors varying in lobe’s distorting angle aremodeled to investigate the relationship between the performance of lobed-mixing exhaustejector and lobe’s distorting angle.4. The guiding cone has been considered an important factor affecting the performanceof the ejectors. The orthogonal test method is again used to identify the exact structuralparameter of the guiding cone that has the greatest influence.5. Experimental research is proceeded respectively on lobed-mixing and piling typeexhaust ejectors to illustrate the accuracy of the numerical simulation.