Effects of Scale Ratio on Flow Characteristics in Moonpool

Title & Authors
Effects of Scale Ratio on Flow Characteristics in Moonpool
Lee, Sang Bong;

Abstract
When a geometric size of moonpool and an inflow velocity are determined based on the similarity of Froude number, Reynolds number is depending on the scale ratio of moonpool geometry. It means that different characteristics of flow fluctuations in moonpool can be observed depending on the scale ratio of moonpool even though Froude number is the same. In the present study two dimensional numerical simulations were performed to investigate the influence of scale ratios on the flow characteristics inside the moonpool. The inflow velocity at several scale ratios was determined to keep Froude number constant. A periodic response was observed in a small size of moonpool while a large moonpool showed complicated fluctuations with various amplitudes and frequencies, which made it difficult to distinguish the statistical steady-state response from the temporal responses in the case of large moonpool. The similarity of Froude number gave rise to a spectral characteristic which was inversely proportional to the square root of scale ratios ($\small{f_{0.5}{\approx}{\sqrt{2}}f_1{\approx}2f_{2.0}}$) but a low frequent occurrence of strong vortex (\$f_{2.0}
Keywords
Moonpool;Scale ratio;Periodic response;Reynolds number;Froude number;
Language
Korean
Cited by
References
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