A higher order boundary element method(HOBEM)is presented for inviscid flow passing cylinders in bounded or unbounded domain.The traditional boundary integral equation is established with respect to the velocity poten...A higher order boundary element method(HOBEM)is presented for inviscid flow passing cylinders in bounded or unbounded domain.The traditional boundary integral equation is established with respect to the velocity potential and its normal derivative.In present work,a new integral equation is derived for the tangential velocity.The boundary is discretized into higher order elements to ensure the continuity of slope at the element nodes.The velocity potential is also expanded with higher order shape functions,in which the unknown coefficients involve the tangential velocity.The expansion then ensures the continuities of the velocity and the slope of the boundary at element nodes.Through extensive comparison of the results for the analytical solution of cylinders,it is shown that the present HOBEM is much more accurate than the conventional BEM.展开更多
The hydrodynamic behaviour of an oscillating wave surge converter(OWSC) in large motion excited by nonlinear waves is investigated. The mechanism through which the wave energy is absorbed in the nonlinear system is an...The hydrodynamic behaviour of an oscillating wave surge converter(OWSC) in large motion excited by nonlinear waves is investigated. The mechanism through which the wave energy is absorbed in the nonlinear system is analysed. The mathematical model used is based on the velocity potential theory together with the fully nonlinear boundary conditions on the moving body surface and deforming free surface. The problem is solved by the boundary element method. Numerical results are obtained to show how to adjust the mechanical properties of the OWSC to achieve the best efficiency in a given wave, together with the nonlinear effect of the wave height. Numerical results are also provided to show the behaviour of a given OWSC in waves of different frequencies and different heights.展开更多
基金financially supported by the National Natural Science Foundation of China (Grant Nos.52271276,52271319,and 52201364)the Natural Science Foundation of Jiangsu Province (Grant No.BK20201006)。
文摘A higher order boundary element method(HOBEM)is presented for inviscid flow passing cylinders in bounded or unbounded domain.The traditional boundary integral equation is established with respect to the velocity potential and its normal derivative.In present work,a new integral equation is derived for the tangential velocity.The boundary is discretized into higher order elements to ensure the continuity of slope at the element nodes.The velocity potential is also expanded with higher order shape functions,in which the unknown coefficients involve the tangential velocity.The expansion then ensures the continuities of the velocity and the slope of the boundary at element nodes.Through extensive comparison of the results for the analytical solution of cylinders,it is shown that the present HOBEM is much more accurate than the conventional BEM.
基金financially supported by Lloyd's Register Foundation through the joint centre involving University College London,Shanghai Jiao Tong University and Harbin Engineering Universitysupported by the National Natural Science Foundation of China(Grant No.11472088)
文摘The hydrodynamic behaviour of an oscillating wave surge converter(OWSC) in large motion excited by nonlinear waves is investigated. The mechanism through which the wave energy is absorbed in the nonlinear system is analysed. The mathematical model used is based on the velocity potential theory together with the fully nonlinear boundary conditions on the moving body surface and deforming free surface. The problem is solved by the boundary element method. Numerical results are obtained to show how to adjust the mechanical properties of the OWSC to achieve the best efficiency in a given wave, together with the nonlinear effect of the wave height. Numerical results are also provided to show the behaviour of a given OWSC in waves of different frequencies and different heights.
