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A fast multipole boundary element method for three-dimensional potential flow problems

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Acta Oceanologica Sinica 2004年第4期23卷 747-756页

作者： TENGBin NINGDezhi GOUYing StateKeyLaboratoryofCoastalandOffshoreEngineering DalianUniversityofTechnologyDalian116024China

A fast multipole methodology (FMM) is developed as a numerical approach to reduce the computational cost andmemory requirements in solving large-scale problems. It is applied to the boundary element method (BEM) for three-dimensional potential flow problems. The algorithm based on mixed multipole expansion and numerical integration isimplemented in combination with an iterative solver. Numerical examinations, on Dirichlet and Neumann problems,are carried out to demonstrate the capability and accuracy of the present method. It has been shown that the methodhas evident advantages in saving memory and computing time when used to solve huge-scale problems which may beprohibitive for the traditional BEM implementation.

关键词： FMM BEM memory saving computing time potential flow

Dissipative free-surface solver for potential flow around hydrofoil distributed with doublets

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Applied Mathematics and Mechanics(English Edition) 2012年第11期33卷 1467-1480页

作者：陈志敏 W. G. PRICE Ship Science University of Southampton

A doublet integral equation is formulated for the two-dimensional dissipative potential flow around a hydrofoil submerged below a free-water surface. The free-water surface is assumed to involve energy dissipation, and thus it is the source of damping. A doublet panel method is developed from incorporation of the dissipative Green function approach and the doublet distributions on the hydrofoil surface. Numerical computations are implemented, and the derived numerical results are in good agreement with analytic solutions and experimental measurements.

关键词： panel method potential flow free-surface wave energy dissipation hydro-foil

A BOUNDARY INTEGRAL EQUATION AND ITS NUMERICAL SOLUTION OF potential flow AROUND SURFACE-IRREGULA-RITIES

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Journal of Hydrodynamics 1993年第1期5卷 70-81页

作者： Guo Ya-kun Wen Xian-yun Institute of Hydraulic Research,Chengdu University of Science and Technology,Chengdu,610065,P.R.China

In this paper,using complex functional theory,the authors turn the potential flow around the surface irregularities in a pressure conduit and semi-infinite platforms into Dirichlet *** on Schwarz formula and by the application of Plemelj's formula,the authors change the problem into the integration of a Cauchy boundary integral equation in the flow plane through the substitution of *** numerical integration,the authors obtain the velocity distribution and pressure coefficient along surface irregularities and *** physical concept of this method is clear,the convergent speed is rapid and the computative effi- ciency is *** calculated values agree well with the measured *** is an effective and simple method in solving potential flow.

关键词： potential flow boundary integral equation numerical integration

Application of dual reciprocity boundary element method for prediction of acoustic characteristics of ducts and silencers with three-dimensional potential flow

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Chinese Journal of Acoustics 2008年第4期27卷 308-321页

作者： WANG Xueren JI Zhenlin College of Power and Eneryy Engineering Harbin Engineering University Harbin 150001

The Dual Reciprocity Boundary Element Method （DRBEM） is applied to predict the acoustic characteristics of ducts and silencers with three-dimensional potential flow, and the basic principle and numerical procedure of the proposed method are introduced. Compared to the Conventional Boundary Element Method （CBEM）, the DRBEM takes into account the second order terms of flow Mach number in the acoustic governing equation, which is suitable for the situations with higher Mach number subsonic flow. The four-pole parameters of a duct and a varying cross-sectional area expansion chamber are predicted with the DRBEM, and the predictions are compared with the one-dimensional analytical solutions and the CBEM results. The comparisons demonstrated that the present method is valid. Transmission loss of silencers with different structures was also calculated with the DRBEM. The results showed that the influence of the three-dimensional flow on the acoustic characteristics of silencers with complex structures is not negligible.

关键词： potential flow acoustic characteristics Boundary Element Method Mach number analytical solutions governing equation second order

A General Boundary Solution Method for potential flow around a 2D Semi-infinite Body

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Advances in Manufacturing 1998年第3期 24-27页

作者： Shen Min(Shanghai Institute of Appl. Math. & Mech.) Deng Kang(College of Material Science and Engineering)

By using Cauchy's integral formula of analytical complex function and the third order complex spline function, a general boundary solution method for solving the complex potential field of the flow field around a 2D semi infinite body is presented in this paper. The pressure coefficients obtained by the present method agree well with those given by Acrivous, showing the validity of our method.

关键词： potential flow semi infinite body boundary element method

Generalized Formulation to Estimate a potential Complex Function of a flow past Multiple Cylinders

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Generalized Formulation to Estimate a Potential Complex Func...

Design Method of Guide Vane for Wells Turbine

The 2012 International Conference on Advanced Material and Manufacturing Science (ICAMMS 2012)

作者： Jan Mateu Armengol Carlos Salinas Sedano State University of Campinas Mechanical Engineering Faculty ETSEIB Technical University of Catalonia(UPC)

This paper presents a generalized formulation to calculate an approximation of the complex potential function due to a flow past over any distribution of circular cylinders with different radius and *** validate the formulation,the stream function over different configurations of cylinders is *** an example,the potential complex function of three different configurations of cylinders in the z-plane is *** addition,in order to show the interference among the cylinders,the velocity and pressure distribution are also calculated.

关键词： potential flow Method of Complex Variables flow past Multiple Cylinders

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Journal of Thermal Science 2006年第2期15卷 126-131页

作者： Masami SUZUKI Department of Mechanical Engineering Graduate School of Engineering The University of Tokyo

Guide vanes are installed in the Wells turbine in order to improve its efficiency, self-rotating characteristics and off design performance with stall. This work attempts to explain the role of these guide vanes on the basis of momentum theory. It is shown that the upstream vanes are more effective in enhancing efficiency than the downstream ones. A design method for guide vanes is suggested based on experimental data and potential theory. Experimental studies carried out by the author confirm the theory proposed.

关键词： wells turbine guide vane cascade potential flow wave energy converter ocean engineering

Three-dimensional oscillation of an acoustic microbubble between two rigid curved plates

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Journal of Hydrodynamics 2021年第5期33卷 1019-1034页

作者： Kawa M.A.Manmi Imad A.Aziz Arun Arjunan Rostam K.Saeed Abdolrahman Dadvand Department ofMathematics College of ScienceSalahaddin University-ErbilKurdistan RegionIraq Department of Information Technology College of Engineering and Computer ScienceLebanese French UniversityKurdistan RegionIraq Faculty of Science and Engineering University of WolverhamptonWolverhamptonUK Faculty of Mechanical Engineering Urmia University of TechnologyUrmiaIran Karlsruhe Institute of Technology(KIT) Institute for Chemical Technology and Polymer ChemistryKarlsruheGermany

Understanding the near boundary acoustic oscillation of microbubbles is critical for the effective design of ultrasonic biomedical devices and surface cleaning ***,this study investigates the three-dimensional microbubble oscillation between two curved rigid plates experiencing a planar acoustic field using boundary integral method(BIM).The numerical model is validated via comparison with the nonlinear oscillation of the bubble governed by the modified Rayleigh-Plesset equation and with the axisymmetric model for an acoustic microbubble in infinite fluid ***,the influence of the wave direction and horizontal standoff distance(h)on the bubble dynamics(including jet velocity,jet direction,centroid movement,total energy,and Kelvin impulse)were *** was concluded that the jet velocity,the maximum radius and the total energy of the bubble are not significantly influenced by the wave direction,while the jet direction and the high-pressure region depend strongly on *** importantly,it was found that the jet velocity and the high-pressure region around the jet in acoustic bubble are drastically larger than their counterparts in the gas bubble.

关键词： Acoustic microbubble bubble dynamics boundary integral method(BIM) two curved plates potential flow

Negative Stiffness Mechanism on An Asymmetric Wave Energy Converter by Using A Weakly Nonlinear potential Model

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China Ocean Engineering 2024年第4期38卷 689-700页

作者： Sunny Kumar POGULURI Dongeun KIM Yoon Hyeok BAE Department of Ocean Engineering IIT MadrasChennaiIndia Multidisciplinary Graduate School Program for Wind Energy Jeju National UniversityJejuRepublic of Korea Mechanical and System Design Engineering Hongik UniversitySeoulRepublic of Korea

Salter's duck,an asymmetrical wave energy converter(WEC)device,showed high efficiency in extracting energy from 2D regular waves in the past;yet,challenges remain for fluctuating wave *** can potentially be addressed by adopting a negative stiffness mechanism(NSM)in WEC devices to enhance system efficiency,even in highly nonlinear and steep 3D waves.A weakly nonlinear model was developed which incorporated a nonlinear restoring moment and NSM into the linear formulations and was applied to an asymmetric WEC using a time domain potential flow *** model was initially validated by comparing it with published experimental and numerical computational fluid dynamics *** current results were in good agreement with the published *** was found that the energy extraction increased in the range of 6%to 17%during the evaluation of the effectiveness of the NSM in regular *** irregular wave conditions,specifically at the design wave conditions for the selected test site,the energy extraction increased by 2.4%,with annual energy production increments of approximately *** findings highlight the potential of NSM in enhancing the performance of asymmetric WEC devices,indicating more efficient energy extraction under various wave conditions.

关键词： asymmetric wave energy converter negative stiffness mechanism weakly nonlinear potential flow power