RATEG: A PROGRAM FOR NUMERICAL SIMULATION OF NONSTATIONARY THERMOHYDRAULICS OF NETS WITH TWOPHASE COOLANT. CALCULATIONAL MODEL AND NUMERICAL SOLUTION METHOD
O.A. Voronova, R.Ya. Gatilova, T.G. Ivchenko, M.S. Samigulin VANT. Ser.: Mat. Mod. Fiz. Proc 1994. Вып.4. С. 2332.
RATEG program is intended for numerical simulation of nonstationary thermohydraulic processes in branching nets with twophase coolant. The description of the models used in the program is presented: net elements (pumps, branchings, local resistences); flow models for vaporfluid coolant and heat transfer in heat elements and numerical solution methods. Two velocity, twotemperature model (2V2T) of coolant flow allows to take into account velocity and temperature nonequilibrium of flow structure, the mode of heat exchange with channel walls and so on. The difference equation system for coolant flow is approximated by linear semiimplicit onestep difference scheme, in which the timestep is not restricted by resistence conditions. Heat transfer in heat elements is calculated in 1D heat, conduction approximation. The program capabilities allow to use it for simulation of lossofcoolant accidents in nuclear power systems.

RATEG: A PROGRAM FOR NUMERICAL SIMULATION OF NON STATIONARY THERMOHYDRAULICS OF NETS WITH TWOPHASE COOLANT. TEST CALCULATIONS
O.A. Voronova, R.Ya. Gatilova. T.G. Ivchenko, M.S.Samigulin VANT. Ser.: Mat. Mod. Fiz. Proc 1994. Вып.4. С. 3338.
The test results are presented for RATEG program intended for numerical simulation of nonstationary flows in branching thernriohydraulic nets, particularly in circulation circuits of nuclear power systems. The simulation is performed for phenomena characteristic of lossofcoolant, accidents: outflow of boiling fluid at depressurization, chocking and turning over of a flow in the vertical channel; flows with heat exchange crisis in the heated channel. The comparison of calculational and experimental data proves acceptability of program accuracy for some applications in describing of such flows. The calculation of stationary mode of WWER440 reactor circuit is performed in simulating of real systems for demonstration of program capabilities.
