本文基于雷诺时均N-S方程(RANS),结合k-ε湍流模型及VOF(Volume of Fluid)方法,对在均匀流体及强分层流体中运动的suboff模型粘性流场及尾迹特征进行数值预报。首先,对均匀流体中suboff粘性流场进行数值试验,并通过网格无关性验证及sub...本文基于雷诺时均N-S方程(RANS),结合k-ε湍流模型及VOF(Volume of Fluid)方法,对在均匀流体及强分层流体中运动的suboff模型粘性流场及尾迹特征进行数值预报。首先,对均匀流体中suboff粘性流场进行数值试验,并通过网格无关性验证及suboff水动力性能、艇体压力分布等计算结果与试验结果的对比验证了本文数值方法的有效性与可靠性。其次,实现了强分层流体中运动suboff内波尾迹的数值预报。通过对比2种工况下suboff尾迹特征的空间分部及细节流场,分析了内波对suboff尾迹的影响方式。展开更多
Submarine maneuverability has been analyzed by means of computational fluid dynamics(CFD).This approach provides an alternative,accurate,and cost-effective method for simulating actual flow.The numerical results show ...Submarine maneuverability has been analyzed by means of computational fluid dynamics(CFD).This approach provides an alternative,accurate,and cost-effective method for simulating actual flow.The numerical results show that the numerical simulation of the viscous flow related to a moving submarine based on the RANS equation with a relevant turbulence model can not only provide rich flow field details such as flow separation,but also accurately predict its hydrodynamic performance.The present study indicates that CFD can be used to forecast the submarine’s maneuverability in the initial design stage.The present results will be used in the future as a basis for analyzing methods to reduce the vibration and noise generated by the submarine.展开更多
The present study aims to investigate the interaction between the free surface and a semi/shallowly submerged underwater vehicle,especially when the submergence depth h is smaller than 0.75D(D:submarine maximum diamet...The present study aims to investigate the interaction between the free surface and a semi/shallowly submerged underwater vehicle,especially when the submergence depth h is smaller than 0.75D(D:submarine maximum diameter).In this respect,the straight-ahead simulations of the generic SUBOFF underwater vehicle geometry are conducted with constant forward velocities using the Unsteady Reynolds-Averaged Navier-Stokes(URANS)equations with a Shear-Stress Transport(SST)k-ωturbulence model in commercial code Fluent,at submergence depths and Froude numbers ranging from h=0 to h=3.3D and from Fn=0.205 to Fn=0.512,respectively.The numerical models are verified against the existing experimental data.The analysis of the obtained results indicates that in the case of the semi and shallowly submerged underwater vehicle(UV),both the submergence depth and forward velocity have a great effect on the behaviors of hydrodynamic forces acting on the UV.The magnitude of maximum total resistance may reach almost five times the value of resistance exerted on the totally submerged hull.Both the forces acting on the UV and the generated waves when the submergence depth h is smaller than 0.75D are significantly different from those whenr h is larger than 0.75D.The conclusions can be used as reference for future research on near free surface motions of underwater vehicles and the design of small water-plane area twin hull.展开更多
文摘本文基于雷诺时均N-S方程(RANS),结合k-ε湍流模型及VOF(Volume of Fluid)方法,对在均匀流体及强分层流体中运动的suboff模型粘性流场及尾迹特征进行数值预报。首先,对均匀流体中suboff粘性流场进行数值试验,并通过网格无关性验证及suboff水动力性能、艇体压力分布等计算结果与试验结果的对比验证了本文数值方法的有效性与可靠性。其次,实现了强分层流体中运动suboff内波尾迹的数值预报。通过对比2种工况下suboff尾迹特征的空间分部及细节流场,分析了内波对suboff尾迹的影响方式。
基金supported by Scientific Research Fund of Ministry of Education Innovation platform open fund Project(No.2018C01044)and(No.2018A03025).
文摘Submarine maneuverability has been analyzed by means of computational fluid dynamics(CFD).This approach provides an alternative,accurate,and cost-effective method for simulating actual flow.The numerical results show that the numerical simulation of the viscous flow related to a moving submarine based on the RANS equation with a relevant turbulence model can not only provide rich flow field details such as flow separation,but also accurately predict its hydrodynamic performance.The present study indicates that CFD can be used to forecast the submarine’s maneuverability in the initial design stage.The present results will be used in the future as a basis for analyzing methods to reduce the vibration and noise generated by the submarine.
基金supported by the National Natural Science Foundation of China(Grant No.52372356).
文摘The present study aims to investigate the interaction between the free surface and a semi/shallowly submerged underwater vehicle,especially when the submergence depth h is smaller than 0.75D(D:submarine maximum diameter).In this respect,the straight-ahead simulations of the generic SUBOFF underwater vehicle geometry are conducted with constant forward velocities using the Unsteady Reynolds-Averaged Navier-Stokes(URANS)equations with a Shear-Stress Transport(SST)k-ωturbulence model in commercial code Fluent,at submergence depths and Froude numbers ranging from h=0 to h=3.3D and from Fn=0.205 to Fn=0.512,respectively.The numerical models are verified against the existing experimental data.The analysis of the obtained results indicates that in the case of the semi and shallowly submerged underwater vehicle(UV),both the submergence depth and forward velocity have a great effect on the behaviors of hydrodynamic forces acting on the UV.The magnitude of maximum total resistance may reach almost five times the value of resistance exerted on the totally submerged hull.Both the forces acting on the UV and the generated waves when the submergence depth h is smaller than 0.75D are significantly different from those whenr h is larger than 0.75D.The conclusions can be used as reference for future research on near free surface motions of underwater vehicles and the design of small water-plane area twin hull.
