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The aerodynamic characteristics of circular cylinder in a channel are studied to make clear the flow feature by solving the Navier-Stokes equation based on the finite volume method with unstructured grids. Reviews are made on with the vorticity, velocity, dynamic pressure, residual and drag, where the Reynolds numbers are 50 and 100. The flows for Re 50 shows the vortex shedding in the wake, and the result is the same as the case of moving cylinder. The ground effect of flat bottom results in the growth of vortex, being generated in the upper side of the cylinder and elongated in the rear. As the cylinder approaches to wall, for example 0.6, the cylinder plays as a role of blockage to obstruct the flow between the cylinder and wall. The drag coefficients are compared with others' results to confirm the validity of the present numerical simulation.

Three dimensional laminar flows are numerically simulated around the submerged spheres. The finite volume based Navier-Stokes equations with unstructured grids are solved to make clear the hydrodynamic phenomena near and far away from the body. Reviews are made on with the vorticity, velocity, dynamic pressure, residuals, drags, etc. The Reynolds numbers under consideration are 425, 300, 250 and 100. In case of small spacing between spheres, the flow is more stable than that past a single sphere. According to the analysis, the flow past two spheres is found to be unstable as the spacing becomes larger. The rear sphere shows the deduction of stagnation pressure, which results in the decrease of the resistance. The predicted drag coefficients verify that the present numerical calculation is reasonable.

The flow analysis has been made by applying the turbulent models in the helically coiled tubes of heat transfer. The k-ε and Spalart-Allmaras turbulent models are used in which the structured grid is applied for the simulation. The velocity vector, the pressure contour, the change of residuals along the iteration number and the friction factors are simulated by solving the Navier-Stokes equations to make clear the Reynolds number effect. The helical tube increases the centrifugal forces by which the wall shear stress become larger on the outer side of the tube. The centrifugal force makes the heat transfer rate locally larger due to the increase of the flow energy, which finds out the close relationship between the pressure drop and friction factor in the internal flow. The present numerical results are compared with others, for example, in the value of friction factor for validation.