Study on the Dynamics of the Bubble under the Combined Action of the Bjerknes Effect of the Free Surface and the Buoyancy

2014 ◽  
Vol 644-650 ◽  
pp. 628-631
Author(s):  
Ke Yi Li ◽  
Zhong Cai Pei
Keyword(s):  
Free Surface ◽  
Boundary Element Method ◽  
Boundary Element ◽  
Potential Flow ◽  
Flow Theory ◽  
Motion Direction ◽  
Potential Flow Theory ◽  
Combined Action ◽  
Element Method

When the bubble moves in the vicinity of a free surface, the movement will be affected by the buoyancy and the Bjerknes effect. Blake and Gibson proposed the criterion which determined the motion direction of the jet and the dynamics of bubble. They proposed the jet wouldn’t be formed in the condition that . Based on the potential flow theory, boundary element method (BEM) is used to calculate three typical examples in this paper in order to study the dynamics of the bubble under the combined action of the Bjerknes effect of the free surface and the buoyancy. It is found out during the analysis that the Blake criterion is applicable to predict the conditions that and .

Verification, Validation, and Best Practices for a High-Order, Potential-Flow Boundary Element Method

2015 ◽  
Author(s):  
W. James Doyle ◽  
Lauren S. Schambach ◽  
Marc V. Smith ◽  
Charles Field ◽  
Christopher J. Hart
Keyword(s):  
Boundary Element Method ◽  
Boundary Element ◽  
Potential Flow ◽  
Best Practice ◽  
High Order ◽  
Data Sets ◽  
Design Environment ◽  
Best Practice Guidelines ◽  
Physical Experiments ◽  
Element Method

Aegir is a medium-fidelity potential flow code that uses a high-order, non-uniform rational B-Spline (NURBS) based boundary-element method for the computation of steady and unsteady ship hydrodynamics. This paper documents verification and validation for Aegir in its steady-state wave resistance prediction mode and Aegir’s LEAPS to Aegir function. A set of best practice guidelines has been created to aid the user in selecting initial input parameters, which reduces the necessary time for verification. This paper also presents validation of the numerical solution versus physical experiments from publically available ship data sets. Aegir has become more prevalent in the naval ship design community and is now a part of the US Navy’s Integrated Hydrodynamic Design Environment (IHDE).

scholarly journals The Prediction of Hull Gesture and Flow Around Ship Based on Taylor Expansion Boundary Element Method

2019 ◽  
Vol 26 (2) ◽  
pp. 198-211
Author(s):  
Jiaye Gong ◽  
Yunbo Li
Keyword(s):  
Boundary Condition ◽  
Free Surface ◽  
Boundary Element Method ◽  
Flow Field ◽  
Boundary Element ◽  
Taylor Expansion ◽  
Surface Condition ◽  
Control Point ◽  
Surface Boundary ◽  
Element Method

Abstract Based on the potential flow theory and traditional boundary element method (BEM), Taylor expansion boundary element method (TEBEM) is introduced in this paper for the prediction of the flow field around ship, as a result, hull gesture and pressure distribution on hull surface are obtained. By this method, dipole strength of every field point is expanded in Taylor expansion, so that approximately continuous hull and free surface boundary condition could be achieved. To close the new equation system, the boundary condition of tangent velocity in every control point is introduced. With the simultaneous solving of hull boundary condition and free surface condition, the disturbance velocity potential could be obtained. The present method is used to predict the flow field and hull gesture of Wigley parabolic hull, Series 60 and KVLCC2 models. To validate the numerical model for full form ship, the wave profile, the computed hull gesture and hull surface pressure of KVLCC2 model are compared with experimental results.

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