Research On The Hydrodynamic Characters Of Unsteady Airfoils And Straight-bladed Turbines

Airfoils are widely used in the fields of shipbuilding, ocean and offshore engineering. To evaluate and analyze the hydrodynamic characters of them has been an important task, especially researches on oscillating airfoils are emphasized in the whole world. But for the present time, there are not researches on 3D dynamic hydrofoils applied to engineering yet.Resources of oceans in our country are abundant. But for the present time, the lever of researches in this field is still low, and we should make more efforts on them. As an important equipment to convert energy to use, the straight bladed turbine is more and more recognized by people. The center parts of turbines are wheels, and the shapes of their sections are basic airfoils. Studies on hydrodynamic characters of them can provide valuable information for researches on straight bladed turbines.The popular CFD software FLUENT was used in this paper to compute the hydrodynamic characters of 2D and 3D airfoils and straight bladed turbines. Meanwhile, the influence of different factors to them was analyzed. Firstly, a 2D airfoil model under steady movement was made in an unbounded fluid to calculate the hydrodynamic characters. Secondly, calculation on hydrodynamic characters of a 3D airfoil under steady movement was also carried out and problems like modification of fine grids and boundary conditions were solved. At the same time, with the powerful function of FLUENT to deal with moving boundaries and grids, the unsteady hydrodynamic characters of an oscillating 3D airfoil was numerically calculated and the influence of different parameters (such as oscillating amplitude, cycle and position of axis) on it was discussed. At last, on the base of those researches, calculations on hydrodynamic characters of straight bladed turbines which turned periodically with time were carried out. By...