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| RANS simulation of viscous flow over full appended submarine and field variables validation and vorticity analysis |
| Received:August 31, 2010 Revised:February 15, 2012 |
| View Full Text View/Add Comment Download reader |
| DOI：10.7511/jslx20124017 |
| KeyWord:submarine SUBOFF RANS simulation viscous flow field variables vorticity |
| Author | Institution |
| 杨琼方 |
海军工程大学 船舶与动力学院, 武汉 |
| 王永生 |
海军工程大学 船舶与动力学院, 武汉 |
| 张志宏 |
海军工程大学 理学院, 武汉 |
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| Abstract: |
| After RANS simulation of full appended SUBOFF submarine’s viscous flow with four groups of grids of the same mesh block topology and close mesh quality and five turbulent models,effects of mesh density and nodes distribution and turbulent models on calculation precision were analyzed,and detailed validation of force integral variables and velocity field variables and vorticity of viscous flow were completed at last.Results show that G4 (1.4 million) with the most mesh density can get the highest precision,which calculated total drag just differ by 0.723% to the experiment.As for the G4 mesh,choosing the SST model in the calculation is the best.Using G4,the predicted pressure coefficient and wall shear stress coefficient distribution both fit very well with the experiment; The numerical precision of the velocity profiles on propeller disk plane is near to the reference,and the calculated radial position for dimensional axial velocity over 0.9 is a little bigger than the experiment,while the rest is good agreement with the data; The precision of the three velocity components at r/R=0.25 is higher than reference too as a whole,and its axial component fits well with the experiment,the radial components’ peak is a little lower while its circumferential position is coincident with the measure.What’s more important,RANS simulation of the G4 successfully captures the complexity vorticity structures,including counter-rotating vortex induced by flow over fairwater cap and stern fin’s tip surface,necklace-shaped vortex pair downstream of the appendages’ root section,shoe-shaped vortex attached upwards of stern fin’s tip surface trailing edge,horse-shoe vortex system induced by the flow around the appendages,vortex induced by flow extrusion within the passages of stern appendages,and the vortex concentration phenomenon on propeller disk plane,even the phenomenon of counter-rotating vortex induced by flow over fairwater cap being stable along the streamwise and getting no effects on vorticity on propeller disk plane,which are all coincident with the numerical results completed by LES presented in reference.This paper shows that under the condition of refined mesh density,the nodes’ reasonable distribution,good mesh quality,credible turbulent model and valid wall-function,the RANS simulation of full appended submarine’s viscous flow can also get the credible field variables and vorticity,so as to offer a powerful solution for the new submarine’s design and performances prediction in marine engineering. |
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