一种用于螺旋桨解析的改进移动参考系方法
A Modified Moving Reference Frame Method for Propeller Resolution
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中文总结 AI 辅助
该研究针对船舶CFD中螺旋桨解析问题，提出改进移动参考系方法，通过空间变化函数缩放旋转速率恢复边界连续性，经推导实现并验证后用于模拟，能准确再现推进量，显著减少局部流场不连续性和伪影，计算成本基本不变。
中文摘要 AI 辅助
准确解析螺旋桨与船体的相互作用对于预测船舶CFD中的自推进点至关重要。滑动界面等运动解析方法计算成本高，经典移动参考系方法无法捕捉非定常相互作用。部分旋转网格方法虽有改进，但旋转与静止区域过渡会导致速度场不连续。本文提出改进的移动参考系方法，通过空间变化函数缩放参考系旋转速率，恢复边界处速度和压力连续性。在RANS求解器中推导并实现控制方程，经泰勒-库埃特解析解验证后应用于模型尺度的敞水螺旋桨和日本散货船自推进模拟。结果表明，两种方法都能准确再现主要积分推进量，但改进方法显著减少了局部流场中的界面不连续性和非物理伪影，且计算成本基本相同。
英文摘要
Accurate resolution of propeller-hull interaction is essential for predicting the self-propulsion point in ship CFD, yet motion-resolving methods such as sliding interfaces (SI) are computationally expensive, while the classical Moving Reference Frame (MRF) approach cannot capture unsteady interaction effects. Partially rotating grid methods bridge this gap by splitting the propeller rotation into a grid-resolved and an MRF component, but the abrupt transition between the rotating and stationary domains introduces discontinuities in the velocity field. This work presents a modified MRF (mMRF) formulation in which the reference-frame rotation rate is scaled by a spatially varying function that decays smoothly from unity near the propeller to zero at the domain interface, restoring velocity and pressure continuity across the boundary. The governing equations are derived and implemented in the RANS solver FreSCo$^+$, verified against the analytical Taylor--Couette solution, and applied to open-water propeller and Japan Bulk Carrier self-propulsion simulations at model scale. Both MRF and mMRF reproduce the principal integral propulsion quantities ($n$, $K_{\mathrm{T}}$, $K_{\mathrm{Q}}$, $1-t$, $1-w_{\mathrm{T}}$, $η_{\mathrm{R}}$) accurately, but the mMRF markedly reduces interface discontinuities and non-physical artifacts in the local flow field, particularly at large MRF fractions, at essentially the same computational cost.
