URANS simulations of ship motion responses in long-crest irregular waves

• Published in: Journal of hydrodynamics. Series B Vol. 26; no. 3; pp. 436 - 446
• Main Author: 沈志荣 叶海轩 万德成
• Format: Journal Article
• Language: English
• Published: Singapore Elsevier Ltd 01.07.2014; Springer Singapore
• Subjects: Accuracy; Computation; Computational fluid dynamics; Computer simulation; Engineering; Engineering Fluid Dynamics; Hydrology/Water Resources; irregular waves; Mathematical models; naoe-FOAM-SJTU solver; Numerical and Computational Physics; OpenFOAM; ship motion response; Ships; Simulation; Solvers; Strip; unsteady incompressible Reynolds-Average Navier-Stokes (URANS) equations; VOF方法; white noise spectrum; 不规则波; 噪声频谱; 模拟; 船舶; 计算时间; 计算流体力学方法; 运动响应; OpenFOAM; unsteady incompressible Reynolds-Average Navier-Stokes (URANS) equations; naoe-FOAM-SJTU solver; ship motion response; white noise spectrum; irregular waves; unsteady incompressible Reynolds-Average Navier-Stokes(URANS) equations
• ISSN: 1001-6058; 1878-0342
• DOI: 10.1016/S1001-6058(14)60050-0

In this paper, numerical prediction of ship motion responses in long-crest irregular waves by the URANS-VOF method is presented. A white noise spectrum is applied to generate the incoming waves to evaluate the motion responses. The procedure can replace a decade of simulations in regular wave with one single run to obtain a complete curve of linear motion response, considerably reducing computation time. A correction procedure is employed to adjust the wave generation signal based on the wave spectrum and achieves fairly better results in the wave tank. Three ship models with five wave conditions are introduced to validate the method. The computations in this paper are completed by using the solver naoe-FOAM-SJTU, a solver developed for ship and ocean engineering based on the open source code OpenFOAM. The computational motion responses by the irregular wave procedure are compared with the results by regular wave, experiments and strip theory. Transfer functions by irregular wave closely agree with the data obtained in the regular waves, showing negligible difference. The comparison between computational results and experiments also show good agreements. The results better predicted by CFD method than strip theories indicate that this method can compensate for the inaccuracy of the strip theories. The results confirm that the irregular wave procedure is a promising method for the accurate prediction of motion responses with less accuracy loss and higher efficiency compared with the regular wave procedure.