Rotor moment of inertia significantly influences the performance of rotating systems, such as wind and tidal turbines, when operating in unsteady environments. However, rotor moment of inertia in itself does not fully define the unsteady behaviour of such rotating systems without taking flow inertia, e.g. the gust acceleration, into consideration. We therefore introduce a normalized inertia number ($I^{\ast }$), which relates the influence of rotor moment of inertia relative to the flow inertia in order to characterize the dynamic response of a generic-rotor system. Experiments are performed in a towing-tank facility using three geometrically-identical rotor models with weighted tips so as to investigate the influence of $I^{\ast }$ on the rotor’s ability to adapt to changing inflow conditions. Gust profiles with four gust durations were tested, ranging from slow quasi-steady operation to rapid disturbances. Rotors operating with sufficiently low $I^{\ast }$ are found to produce higher normalized power during the fastest tested gust when compared to the quasi-steady operation. For instance, the power output of the rotor model with ($I^{\ast }=3.2\times 10^{-3}$) is, at its maximum, 30% higher during the fastest gust versus quasi-steady operation. However, by increasing $I^{\ast }$ on the same rotor model to $8.7\times 10^{-3}$, by decreasing the flow inertia, the rotor model produced, at maximum, only 19% higher power output. Therefore, we are able to show that our normalization $I^{\ast }$ is a reasonable way to determine the dynamic performance of a rotating system during a gust.

当在不稳定环境中运行时，转子转动惯量会显着影响旋转系统（例如风力涡轮机和潮汐涡轮机）的性能。然而，在不考虑流动惯性（例如阵风加速度）的情况下，转子转动惯量本身并不能完全定义这种旋转系统的不稳定行为。因此，我们引入归一化惯性数（${\mathrm{一世}}^{＊}$)，它涉及转子转动惯量相对于流动惯量的影响，以表征通用转子系统的动态响应。实验是在牵引油箱设施中使用三个带加权尖端的几何相同的转子模型进行的，以研究${\mathrm{一世}}^{＊}$转子适应不断变化的流入条件的能力。测试了四个阵风持续时间的阵风剖面，范围从缓慢的准稳定运行到快速扰动。转子在足够低的情况下运行${\mathrm{一世}}^{＊}$与准稳态操作相比，发现在最快的测试阵风期间产生更高的归一化功率。例如，转子模型的功率输出具有（${\mathrm{一世}}^{＊}=3.2\times 10^{-3}$) 在最快阵风与准稳定运行期间最多高 30%。然而，通过增加${\mathrm{一世}}^{＊}$ 在相同的转子模型上 $8.7\times 10^{-3}$，通过降低流动惯量，转子模型产生的功率输出最多仅提高 19%。因此，我们能够证明我们的归一化${\mathrm{一世}}^{＊}$ 是确定阵风期间旋转系统动态性能的合理方法。