Evaluation of methods to Estimate Hydrodynamic Force Coefficients of Underwater Vehicle based on CFD

2013 ◽  
Vol 46 (33) ◽  
pp. 197-202 ◽  
Author(s):  
Hiroyoshi Suzuki ◽  
Junki Sakaguchi ◽  
Tomoya Inoue ◽  
Yoshitaka Watanabe ◽  
Hiroshi Yoshida
1969 ◽  
Vol 95 (5) ◽  
pp. 1717-1717
Author(s):  
Colin J. Apelt ◽  
Lewis T. Isaacs

1968 ◽  
Vol 94 (1) ◽  
pp. 17-30
Author(s):  
Colin J. Apelt ◽  
Lewis T. Isaacs

2021 ◽  
Vol 219 ◽  
pp. 108272
Author(s):  
Wanhai Xu ◽  
Shuhai Zhang ◽  
Yexuan Ma ◽  
Bin Liu ◽  
Junlei Wang

2012 ◽  
Vol 625 ◽  
pp. 84-87 ◽  
Author(s):  
Hai Jun Liu ◽  
Xing Zhi Peng ◽  
Zhen Zhu Zou

The vertical launch of the gas curtain is a new underwater launch technology. The gravity effect of the launch speed on hydrodynamic characteristics of the underwater vehicle vertical launching by using the gas curtain has been studied by adopting the multiphase VOF model and the standardturbulence model. The relationship between the launch speed and the shape of the underwater vehicle has been achieved by using the numerical simulation. The relationships between the launch speed and the hydrodynamic characteristics of the underwater vehicle vertically launching from the tube, navigating in water and exiting water have been investigated by using numerical simulation. The hydrodynamic characteristics of underwater vehicle vertical launching by using the gas curtain method are small. The effects of the launch speed on the hydrodynamic characteristics of the underwater vehicle vertical launching in the gas curtain are small.


Author(s):  
Jie Wu ◽  
Halvor Lie ◽  
Carl M. Larsen ◽  
Stergios Liapis

It has long been known that in-line (IL) response will influence cross-flow (CF) vortex shedding forces and vice versa. However, empirical codes for prediction of vortex induced vibrations (VIV) of slender marine structures have so far been limited to handle CF or IL response separately without taking into account the interaction between the two response modes. The motion phase angle between IL and CF displacement is a key parameter to be included in the empirical codes in order to model such interaction. The present study uses the data from Shell’s High mode VIV experiments that were performed at the MARINTEK Offshore Basin in March 2011. This extensive test program provides a rich dataset for measuring the motion phase angle and hydrodynamic force coefficients under different flow conditions. It is found that the energy transfer from the fluid to the pipe is related to counter-clockwise trajectories inside the excitation region; while clockwise trajectories are associated with hydrodynamic damping forces. The influence of the travelling wave behavior on motion phase angle and hydrodynamic force coefficients are also studied. It was found that the spatial variation of the motion phase angle of the beam is different when travelling waves dominate the response.


1996 ◽  
Vol 118 (3) ◽  
pp. 608-616 ◽  
Author(s):  
J. X. Zhang ◽  
J. B. Roberts

A centrally grooved short squeeze film damper (SFD), together with its lubricant supply mechanism (LSM), is analyzed, using an integrated theoretical model. It is shown that the traditional analysis for such a damper, where the effects of the central groove and the LSM are ignored, can lead to a seven-fold underestimation of the magnitude of the hydrodynamic force coefficients. The new theory gives predictions for the damping coefficients which are in good agreement with corresponding experimental results. Moreover, a five-fold improvement is obtained for both the temporal and convective inertia coefficients, at low values of eccentricity. The new model leads to the prediction of a nonzero fluid static force which, in conformity with experimental results, is linearly related to the supply pressure. The existence of this static force has not been explained by previous theoretical work on SFDs.


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