Effects of some geometric parameters on hemicylinder bumps placed on straight and curved nonsmoothsurfaces

Almost in the all researches about non-smooth surfaces, the drag on total surface is considered and theeffect of geometrical and flow parameters on the bumps placed on the surface are not studied separately. The shapeand geometry of these bumps has a significant effect on the final drag reduction and the topology design of a nonsmoothsurface is highly affected by characteristics of these bumps. The flow past three hemi-cylindrical bumpsplaced on smooth and curved boundaries was simulated using the lattice Boltzmann method (LBM) in this paper.The LBM has been built up on the D2Q9 model and the single relaxation time method called the Lattice-BGK(Bhatnagar-Gross-Krook) model. The effect of some parameters including the distance between bumps, the size ofbumps and Reynolds number in the case of straight boundary and the size of bumps and angular position of bump’scenter in the case of curved boundary are studied.

کلیدواژه ها:

Lattice Boltzmann method ، Non-smooth surface ، Bumps ، Drag coefficient