Nowadays, most studies on the dynamic properties of annular gaps focus only on the force characteristics due to translational motions, while the tilt and moment coefficients are less well studied. Therefore, there is hardly any reliable experimental data for the additional coefficients that can be used for validation purpose. To improve this, a test rig first presented by Kuhr (2022); Kuhr et al. (2022a) is used to experimentally determine the dynamic force and moment characteristics of three annuli of different lengths. By using active magnetic bearings, the rotor is excited with user-defined frequencies and the rotor position and the forces and moments induced by the flow field in the annulus are measured. To obtain accurate and reliable experimental data, extensive preliminary studies are carried out to determine the known characteristics of the test rig rotor and the added mass and inertia imposed by the test rig. Subsequently, an elaborate uncertainty quantification is carried out to quantify the measurement uncertainties. The experimental results, i.e. the 48 rotordynamic coefficients, are compared to a calculation method by Kuhr (2022); Kuhr et al. (2022b). It is shown that the presented experimental data agree well with the calculation method, especially for the additional rotordynamic tilt and moment coefficients. Furthermore, it is shown that the annulus length significantly influences the coefficients of the first sub-matrix. A dependence of the additional coefficients on the length is recognisable, but less pronounced. Even for the shortest investigated annulus, i.e. $L≔\tilde{L}/\tilde{R}=1$, the stiffness coefficients due to the forces from the angular motion of the rotor are of the same order of magnitude as the stiffness coefficients due to the forces from the translational motion. This supports recent results by Kuhr (2022); Kuhr et al. (2022b), indicating that the additional coefficients become relevant much earlier than assumed throughout the literature, cf. Childs (1993).

目前，对环形间隙动力学特性的研究大多集中于平移运动引起的力特性，而对倾斜系数和力矩系数的研究较少。因此，几乎没有任何可用于验证目的的附加系数的可靠实验数据。为了改进这一点，Kuhr (2022) 首次提出了一个测试台；库尔等。（2022a）用于实验确定三个不同长度的环的动态力和力矩特性。通过使用主动磁轴承，转子以用户定义的频率被激励，转子位置以及环形空间中流场引起的力和力矩被测量。为获得准确可靠的实验数据，进行了广泛的初步研究，以确定试验台转子的已知特性以及试验台施加的附加质量和惯性。随后，进行了详细的不确定性量化以量化测量不确定性。实验结果，即48个转子动力系数，与Kuhr（2022）的计算方法进行了比较；库尔等。(2022b)。结果表明，所提供的实验数据与计算方法吻合得很好，特别是对于附加的转子动力学倾斜和力矩系数。此外，还表明环形长度显着影响第一子矩阵的系数。附加系数对长度的依赖性是可识别的，但不太明显。即使是最短的调查环，即 进行了详细的不确定性量化以量化测量不确定性。实验结果，即48个转子动力系数，与Kuhr（2022）的计算方法进行了比较；库尔等。(2022b)。结果表明，所提供的实验数据与计算方法吻合得很好，特别是对于附加的转子动力学倾斜和力矩系数。此外，还表明环形长度显着影响第一子矩阵的系数。附加系数对长度的依赖性是可识别的，但不太明显。即使是最短的调查环，即 进行了详细的不确定性量化以量化测量不确定性。实验结果，即48个转子动力系数，与Kuhr（2022）的计算方法进行了比较；库尔等。(2022b)。结果表明，所提供的实验数据与计算方法吻合得很好，特别是对于附加的转子动力学倾斜和力矩系数。此外，还表明环形长度显着影响第一子矩阵的系数。附加系数对长度的依赖性是可识别的，但不太明显。即使是最短的调查环，即 结果表明，所提供的实验数据与计算方法吻合得很好，特别是对于附加的转子动力学倾斜和力矩系数。此外，还表明环形长度显着影响第一子矩阵的系数。附加系数对长度的依赖性是可识别的，但不太明显。即使是最短的调查环，即 结果表明，所提供的实验数据与计算方法吻合得很好，特别是对于附加的转子动力学倾斜和力矩系数。此外，还表明环形长度显着影响第一子矩阵的系数。附加系数对长度的依赖性是可识别的，但不太明显。即使是最短的调查环，即$\mathrm{大号}≔\widetilde{\mathrm{大号}}/\tilde{R}=\mathrm{1个}$，由转子角运动产生的力引起的刚度系数与由平移运动产生的力引起的刚度系数具有相同的数量级。这支持了 Kuhr (2022) 最近的结果；库尔等。（2022b），表明附加系数变得相关的时间比整个文献中假设的要早得多，参见。蔡尔兹 (1993)。