[en] The discussion briefly establishes some requisite concepts of differential equation theory, and applies these to describe methods for numerical solution of the thermalhydraulic conservation equations in their various forms. The intent is to cover the general methodology without obscuring the principles with details. As a short overview of computational thermalhydraulics, the material provides an introductory foundation, so that those working on the application of thermalhydraulic codes can begin to understand the many intricacies involved without having to locate and read the references given. Those intending to work in code development will need to read and understand all the references. (author). 49 refs

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[en] A new iterative approach has been developed for multidimensional computational analysis of two fluid flow. It has been implemented and tested in a two-dimensional computer code. Parametric surveys are described to illustrate that this code rationally predicts separation of two fluid flows under gravitational and centrifugal influences. Comparisons are made between behaviour computed by the code, and results reported in experimental studies of air and water flowing in elbows and pipes. Plans for extending the code to three dimensions are discussed, as are methods for incorporating an improved model of turbulence

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[en] Results of a thermal-hydraulic analysis of the Westinghouse Model 51 recirculating steam generator are presented and discussed for operating conditions at 100%, 50% and 20% of nominal power. The analysis was performed using the THIRST code, which incorporates a three-dimensional, steady state homogeneous two-phase flow model. The methodology, assumptions and empirical correlations which were used in THIRST are discussed briefly. Quantitative results from the code are given for each power level in tabular and graphical form. These include parameters characterizing overall performance of the unit and complete local details of the flow field

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[en] In this paper ASSERT predictions are compared with the Marviken 6-rod bundle and 36+1 rod bundle. The predictions are presented for two experiments in the 6-rod bundle and four experiments in the 36+1 rod bundle. For low inlet subcooling, the void predictions are in good agreement with the experimental data. For high inlet subcooling, however, the agreement is not as good. This is attributed to the fact that in the high inlet subcooling experiments, single phase turbulent mixing plays a more important role in determining flow conditions in the bundle

[en] The algorithm due to Gear is recognized as one of the best available integration routines, permitting large time steps while maintaining acceptable error tolerance and stability. The method is implicit, requiring a matrix solution involving the Jacobian. This has hitherto required excessive storage for large equation systems (>100 equations). The algorithm has been used for the solution of small systems involving neutron kinetics, and encouraging results motivated an investigation of the application of sparse matrix techniques to the matrix manipulation within the algorithm. The resulting routines handle large systems of equations very efficiently. Part 1 of this paper describes these new routines, and Part 2 discusses their application to neutron kinetics. (author)