标题： 从涡旋到力 - 一种用于三维涡旋主导流动中非定常升力生成的数据驱动框架 显示英文标题

标题： From vortices to forces - a data-driven framework for unsteady lift generation in three-dimensional vortex-dominated flows

摘要： 在流体流动中，浸入其中的物体所受到的时间变化的流致力在自然和工程系统中起着关键作用，从生物运动到推进和能量收集装置。这些瞬态力通常源于复杂的动态涡旋相互作用，可能会增强或降低系统性能。然而，建立涡旋结构与力瞬变之间的明确因果关系仍然具有挑战性，特别是在高雷诺数的名义上三维流动中。在本研究中，我们研究了以跨度为基础的雷诺数为25,500的旋转叶片的非定常升力生成。该直接数值模拟的升力历史显示了与快速演变的流动结构相关的早期时间极值，包括前缘和尖端涡旋的形成、演变和破裂。为了量化这些涡旋结构对升力瞬变的影响，我们应用了力分解方法（FPM），该方法量化了由涡旋相关效应引起的表面压力力。从FPM中得出两个指标——$Q$-强度和涡旋接近度——用于对涡旋对升力的影响进行定量评估。这种分析确认并扩展了先前研究中的定性见解，并提供了一个简单易用的数据驱动框架，用于将非定常力归因于特定的流动特征，潜在应用于非定常空气动力学力起核心作用的系统的设计和控制。 显示英文摘要

摘要： Time-varying flow-induced forces on bodies immersed in fluid flows play a key role across a range of natural and engineered systems, from biological locomotion to propulsion and energy-harvesting devices. These transient forces often arise from complex, dynamic vortex interactions and can either enhance or degrade system performance. However, establishing a clear causal link between vortex structures and force transients remains challenging, especially in high-Reynolds number nominally three-dimensional flows. In this study, we investigate the unsteady lift generation on a rotor blade that is impulsively started with a span-based Reynolds number of 25,500. The lift history from this direct-numerical simulation reveals distinct early-time extrema associated with rapidly evolving flow structures, including the formation, evolution, and breakdown of leading-edge and tip vortices. To quantify the influence of these vortical structures on the lift transients, we apply the force partitioning method (FPM) that quantifies the surface pressure forces induced by vortex-associated effects. Two metrics - $Q$-strength and vortex proximity - are derived from FPM to provide a quantitative assessment of the influence of vortices on the lift force. This analysis confirms and extends qualitative insights from prior studies, and offers a simple-to-apply data-enabled framework for attributing unsteady forces to specific flow features, with potential applications in the design and control of systems where unsteady aerodynamic forces play a central role.