مطالعه تجربي و عددي كاهش پساي اصطكاكي با استفاده از بهينه سازي سطح گرمايش در اصيام تقارن محور

An Experimental and Numerical Study of Drag Reduction by Optimization of a Heated Surface of an Axisyminetric Body

Friction drag reduction in Axisymmetric bodies with heating the surface in the turbulent boundary layer is investigated experimentally and numerically. For wind tunnel test, an Axisymmetric model, nearly like an airplane body, with a length of 0.5 m and taper ratio of f 0 is manufactured which, the quarter length of its tip and end has elliptical form and the others are flat Also, axisyinmeiric form of the thin layer Navier- Stokes equations, using Baldwin-Lomax turbulence model is applied for the numerical simulation. Optimization of the heating area is performed by dividing the flat section of the model to five equal segments and therefore, the effects of temperature variation in various segments and numbers of heated segments are investigated The experimental and numerical results show that, heating the first segment to 100^4, causes 24.4 (gip.) and 23.8 (Num.) percent reduction in drag force, which show good agreements. The maximum drag reduction occurs in concentrated heating.