Vertical-axis wind turbines’ simpler design and low center of gravity make them ideal for floating wind applications. However, efficient design optimization of floating systems requires fast and accurate models. Low-fidelity vertical-axis turbine aerodynamic models, including double multiple streamtube and actuator cylinder theory, were created during the 1980s. Commercial development of vertical-axis turbines all but ceased in the 1990s until around 2010 when interest resurged for floating applications. Despite the age of these models, the original assumptions (2-D, rigid, steady, straight bladed) have not been revisited in full. When the current low-fidelity formulations are applied to modern turbines in the unsteady domain, aerodynamic load errors nearing 50% are found, consistent with prior literature. However, a set of steady and unsteady modifications that remove the majority of error is identified, limiting it near 5%. This paper shows how to reformulate the steady models to allow for unsteady inputs including turbulence, deforming blades, and variable rotational speed. A new unsteady approximation that increases numerical speed by $5–10\times$ is also presented. Combined, these modifications enable full-turbine unsteady simulations with accuracy comparable to higher-fidelity vortex methods, but over $5000\times$ faster.

垂直轴风力涡轮机更简单的设计和低重心使其成为浮动风力应用的理想选择。然而，浮动系统的有效设计优化需要快速准确的模型。低保真垂直轴涡轮空气动力学模型，包括双多流管和致动器气缸理论，是在 1980 年代创建的。垂直轴涡轮机的商业开发在 1990 年代几乎停止，直到 2010 年左右对浮动应用的兴趣重新抬头。尽管这些模型已经过时，但尚未完全重新考虑原始假设（二维、刚性、稳定、直刃）。当当前的低保真公式应用于非定常域中的现代涡轮机时，发现空气动力载荷误差接近 50%，与先前的文献一致。然而，确定了一组消除大部分错误的稳定和非稳定修改，将其限制在 5% 附近。本文展示了如何重新制定稳定模型以允许包括湍流、变形叶片和可变转速在内的不稳定输入。一种新的非定常近似，可将数值速度提高$5\mathrm{——}10\times$还介绍了。综合起来，这些修改使全涡轮非定常模拟的精度与高保真涡流方法相当，但超过$5000\times$ 快点。