基于RANS和DES法船体绕流模拟及不确定度分析

Uncertainty Analysis in CFD for Flow Simulation Around Ship Using RANS and DES

基于计算流体力学(CFD)不确定度分析的推荐规程,对采用雷诺平均的纳维-斯托克斯方程(RANS)和分离涡模拟(DES)2种模型预报的船舶阻力和波形结果分别进行CFD不确定度分析.数值不确定度主要考虑网格尺寸,按照加细比为42生成3套网格进行计算,并估计网格误差和不确定度.研究分析表明了验证和确认规程对CFD不同数学模型的实用性,建立了基于2种数学模型下模拟结果的验证和确认等级.

Procedures for uncertainty analysis in CFD recommended by the ITTC（International Towing Tank Conference） have been used widely among methods of error estimate and credibility assessment in the field of ship.The method includes verification and validation which qualify the numerical and modeling uncertainty.Following the procedures,the results of uncertainty analysis for resistance and wave profile which are computed by RANS and DES methods（detached eddy simulation） was verified and validated.Numerical verification studies in grid convergence were performed using three grids with grid refinement ratio 4 2.The uncertainty results will lay the foundation for the development of CFD uncertainty analysis.The work demonstrates the usefulness of the proposed verification and validation procedures and establishes the levels of verification and validation of the simulation results in two different mathematical models.