Mechanical EngineeringDepartment, Ferdowsi University of Mashhad
Mechanical Engineering Department, Ferdowsi University of Mashhad
Mecanical Engineering, erdowsi University of Mashhad
The optimal shape of a two dimensional turbulator above an isothermal flat plate is found by using numerical simulation. The turbulent boundary layer over the flat plate was disrupted at various situations by inserting a quadrilateral bar where the boundary layer thickness kept more than three times greater than the insert\\'s height. As a result, the overall heat transfer coefficient of the wall as well as the skin friction coefficient was altered. The single objective Genetic Algorithm (GA) coupled with the modified Teach-t code were employed to optimize the shape and distance of the obstacle from the plate. When the optimal geometry employed, the mean heat transfer coefficient is enhanced by more than 51% over the affected area. Flow features around the quad, each makes its own contribution to the heat transfer change. The stagnation point formed on the frontal face of the body accounts for the slight decrease in the heat transfer coefficient, while the jet underneath the obstacle followed by the developing boundary layer are responsible for the sudden increase of the heat transfer coefficient. However, the downstream wake zone makes the main and widespread contribution.