| Summary: | Research and study into gas-liquid countercurrent two-phase flow in a model of pressurized water reactor (PWR) hot leg has been carried out over the last several decades. An extensive experimental data has been accumulated from these studies, leading to the development of phenomenological correlations and scaling parameters of the countercurrent flow limitation (CCFL). However, most of the proposed correlations apply under a relatively narrow range of conditions, generally limited to the test section conditions and/or geometry. Moreover the development of mechanistic models based on the underlying physical processes has been limited. In contrast to this mechanistic form of modelling, the implementation of computational fluid dynamics (CFD) techniques has also been pursued, but the considerable robust three-dimensional (3D) closure relations for this application remain an unachieved goal due to lack of detailed phenomeno-logical knowledge and consequent application of empirical one-dimensional experimental correlations to the multidimensional problem.
Signal analysis performed a good method for identifying the flow pattern on counter current flow limitation (CCFL). In signal analysis the commonly was used to monitor the flow pattern is the local pressure fluctuation. Signal time series (time series) collected analyzed statistical / stochastic to obtain the desired information. Type or statistical calculations used stochastic analysis is the mean value of the signal and Probability Distribution Function of a pressure difference signal (PDF), Power Spectral Density (PSD) of a pressure difference signal.
This research has been improved with signal processing method using MATLAB® software by changing the numerical data to the algorithm. The objectives is to measure wave distribution in a various points of series of superficial gas and water velocity. Also to define the flow pattern, and CCFL characteristics.
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