Based on CFD/IR(computational fluid dynamics/infrared radiation) numerical calculations

the effects of shelter covering fixed at nozzle trailing edge and cooling air injected inside the shelter covering passage on infrared radiation characteristics of turbofan engine two-dimensional nozzle with aspect ratio 3.33 were investigated.The results based on the present parameters show that

ejected or forced cooling air flow through shelter covering passage enhances further mixing with plume

and suppresses plume infrared radiation in comparison with pure two-dimensional nozzle.As the cooling air massflow increases

the cooling action on nozzle trailing edge is more obvious.Utilizing nozzle ejection effectively could achieve satisfactory infrared radiation suppression.The suppression action on nozzle total infrared radiation with shelter covering is only realized in the detecting azimuth where the infrared radiation from nozzle inner walls is predominant.