Deciding optimal parameter for internal wavemaker using coupling of Dakota and OpenFOAM

Abstract

In order to generate a water wave adequately in numerical simulation, several specialized techniques have been developed: internal wavemaker, static boundary method and moving boundary method. For internal wavemaker, especially, geometry of mass source region needs to be decided minimizing numerical error. Chen and Hsiao [1] suggested the method to set the dimension of wavemaker, deriving height from linear wave theory and constructing empirical formula about wavenumber and width of wavemaker, with FLOW-3D code. The procedure, however, required hundreds of trial calculations, followed by excessive computational cost. In this paper, automated process to find optimal geometry for given relative water depth is proposed, introducing coupling of DAKOTA and OpenFOAM. The waves2Foam utility had been modified to simulate the generation of second-order stokes wave and linked with DAKOTA to control the input file and observe the output file. mass source region needs to be decided minimizing numerical error. Chen and Hsiao [1] suggested the method to set the dimension of wavemaker, deriving height from linear wave theory and constructing empirical formula about wavenumber and width of wavemaker, with FLOW-3D code. The procedure, however, required hundreds of trial calculations, followed by excessive computational cost. In this paper, automated process to find optimal geometry for given relative water depth is proposed, introducing coupling of DAKOTA and OpenFOAM. The waves2Foam utility had been modified to simulate the generation of second-order stokes wave and linked with DAKOTA to control the input file and observe the output file.