NUMERICAL GENERATION OF REGULAR WAVES USING DISCRETE ANALYTICAL DATA AS BOUNDARY CONDITION OF PRESCRIBED VELOCITY
Bianca Neves Machado1; Elissandro Vaz Kisner1; Maycon da Silveira Paiva1; Mateus das Neves Gomes2; Luiz Alberto Oliveira Rocha3; Wiliam Correa Marques1; Elizaldo Domingues dos Santos1; Liércio André Isoldi1
1 Universidade Federal do Rio Grande; 2 Instituto Federal do Paraná; 3 Universidade do Vale do Rio dos Sinos
doi:10.20906/CPS/CILAMCE2017-0816
Resumo
This paper aims to computationally analyze a wave tank in two situations: laboratory scale and real scale. To do so, the FLUENT software was employed, which is a Computational Fluid Dynamic (CFD) package based on the Finite Volume Method (FVM). The study intention is to evaluate a new system to impose the velocity boundary condition for the regular numerical waves generation, using transient discrete values. For this, we compared the amplitude of the numerical waves generated by this proceeding with the waves generated through the imposition of prescribed velocities by means a time-dependent function -with the User Defined Function (UDF) tool in FLUENT- aiming to verify this computational modeling. Therefore, the proposed methodology for the waves generation is based on imposition of horizontal and vertical velocity components of the regular wave from an analytical database. This methodology, in FLUENT software, is possible due to the Table Data tool and these data are inserted in FLUENT through a data entry in table format, called Boundary Profiles, making feasible the use of discrete transient data as velocity boundary conditions. A bidimensional computational domain (2D) generated with the GAMBIT software was used. The Volume of Fluid (VOF) multiphase model was applied in the treatment of the water-air interaction, so the computational model solves the conservation equations of mass and momentum associated with the transport equation of the volumetric fraction. The results indicated that the proposed computational model, using discrete data as velocity boundary conditions for the regular waves generation, can be satisfactorily applied. In addition, this methodology allows a significant reduction in processing time of numerical simulations, without loss of accuracy. In this way, the present work contributes for future geometric optimization studies of Wave Energy Converters (WEC) employing the Constructal Design method.
Palavras-chave: Boundary Condition; Prescribed Velocities; Table Data; User Defined Function (UDF); Computational Modeling