Breaking wave simulations for a high-speed surface vessel with hybrid THINC and HRIC schemes

Abstract

To simulate the ship-induced breaking waves with high-accuracy VOF (volume of fluid) schemes, the unstructured THINC (tangent of hyperbola for interface capturing) type scheme was selected as the main interface capturing method.Particularly, an extension version of THINC/QQ (THINC method with quadratic surface representation and Gaussian quadrature), namely THINC/QQ-SF (THINC/QQ extended for split-face unstructured cells) was used. The computational domain was discretized by the trimmed meshes of STAR-CCM+. The mesh cells were categorized into three groups, including regular unstructured (i.e. hexahedral, tetrahedral, prismatic and pyramidal) cells, split-face unstructured cells and polyhedral cells. THINC/QQ-SF was applied for the first two cell groups, which take up most of the space. The algebraic VOF scheme of HRIC (high-resolution interface capturing) which has the advantage of algorithm simplicity, was implemented for the third cell group. To validate the performance of THINC/QQ-SF and HRIC, a series of testing meshes were designed for the pure VOF advection cases. Additionally, the geometric VOF scheme of isoAdvector was also involved for comparisons. In terms of the accuracy, THINC/QQ-SF is similar with isoAdvector, both of which are much better than HRIC. For the efficiency, both THINC/QQ-SF and HRIC have obvious advantages over isoAdvector under the present conditions. Then, the hull form of DTMB (David Taylor model basin) 5415 was chosen for testing, under the Froude number of 0.35. By using the combination of THINC/QQ-SF and HRIC (i.e. THINC/QQ-SF & HRIC), the compactness of the interface can be maintained. Besides, the wave elevations are well agreed with the published experiment. For the averaged calm-water resistance, the present strategy can obtain more accurate results with fewer (or much fewer) cells, compared with the previous CFD studies. To better show the advantages of the hybrid method, the simulations with pure HRIC were also conducted. Compared with pure HRIC, THINC/QQ-SF & HRIC can better capture the wave breaking details with less numerical diffusion, and the reliability of the resistance prediction is higher.