Calculation of horizontal two-dimensional water temperature distribution in the sea surface effected by waste cooling water

The purpose of this paper is to determine the sea water temperature distribution, when thermal and nuclear power plants discharge warm waste water as cooling water. Investigations on this problem have been carried out so far in Central Research Institute of Electric Power Industry and others, and it is considered to solve the thermal diffusion equation and the equation of motion for incompressible fluid described by partial differential equations. Though the boundary conditions for water temperature are required to solve the above mentioned thermal diffusion equation, treatment of the boundary conditions was investigated as there are the unknown problems. First, the correct determination of boundary conditions was investigated for one dimensional distribution, the theoretical consideration of which is easy. Then the two-dimensional distribution was considered regarding difference calculus for the equations of motion and continuity of fluid, relations between the fixed boundary conditions of fluid velocity and pressure-calculating formulae, and propagation of error. MAC method used is a flexible solving method easily applicable to three-dimensional problems, though it is the method to use difference calculus for solving the motion of water. (Wakatsuki, Y.)