Quasi-two-dimensional numerical model for stability simulation of a cable-in-conduit conductor

摘要

We have developed numerical code for stabilitysimulation of a cable-in-conduit conductor (CICC), POCHI,resulting in improved accuracy in stability simulation. However,there still remains some degree of error in evaluation for removingheat from the strand to the coolant because of limitations of theanalytical model. In the new model, coolant temperature iscalculated on two-dimensional grids in the effective thermalboundary layer around the strand, in which the coolant temperaturechanges from the strand temperature to that of the coolant mainflow, neglecting the effect of coolant convection and heatconduction in the conductor axis direction. (Our model is thencalled 'quasi-two-dimensional'.) In addition, a non-uniform meshsystem is applied for numerical calculation to reducecomputational (CPU) time. The simulation results obtained byusing POCHI and an improved version (POCHI2) were comparedwith the experimental results of stability for a small CICC forverification of the codes. Both simulation results were in goodagreement with those of the experiment in the magnitude.However, dependence of the stability calculated by POCHI on theinitial coolant flow rate had some inconsistencies with theexperiment. These inconsistencies could be removed by the use ofPOCHI2 with a reasonable increase, only a few times longer, inCPU time. These results verify the validity of POCHI2.