Calculation of fluid circulation patterns in the vicinity of submerged jets using ORSMAC

Abstract

As the world demand for electricity is met by large coal- or nuclear-fueled central generating stations, the effluent streams from these plants will have an increasingly important impact on the local environment. The Nuclear Regulatory Commission has a responsibility to assess the impact of proposed and operating nuclear power plants. To support this NRC mission, a numerical algorithm and associated computer program have been developed to predict the temperatures occurring in the immediate vicinity (the near field) of a hot water discharge from a power plant. The algorithm is a natural extension of the classic Marker-and-Cell (MAC) technique developed by F.H. Harlow at the Los Alamos Scientific Laboratory. ORSMAC (Oak Ridge Simplified Marker and Cell) adds the logic for simple turbulence modeling, energy conservation and buoyancy effects to the MAC model. Modern numerical techniques have been used wherever practical. The MAC and SMAC (Simplified MAC) algorithms are reviewed, and the ORSMAC algorithm is described. The finite difference analogs are given and discussed. Solutions for several sample problems are presented which illustrate the features of the ORSMAC algorithm. A complete FORTRAN listing is included with input and sample output. Recommendations for further testing are included.