عنوان مقاله [English]
In this study, ducts are designed to reduce the IR effect of airplane plume. Cooling the hot plume of airplane is caused to reduce the view of radar and as result airplane stealth. The elliptical shape exhaust of ducts is caused to stretching of flow in wings direction and cooling of hot plume. The simulation is done with ANSYS Fluent Software version of 2015, using of the normalized k-ε RNG turbulence model and 12 million meshes. As results, tracking range reduced through designed Ducts with aspect ratio of 2.5, 4.5, 6.5 and 8.5 rather than circle duct. This reduce is respectively 14, 19, 28 & 34 percent. In this meantime, thrust is decreased in ducts with aspect ratio of 6.5 and 8.5 the amount respectively 5 and 10 percent. Finally, duct with aspect ratio of 6.5 is selected as an optimized duct as results and comparing of radar range and thrust of flows. Selected duct is reduced radar range to 28%.