Partial admission can ensure the efficient operation of the turbine unit while adjusting the aerodynamic load. It has a wide range of application prospects due to its advantages. However, the rotor blades of partial admission turbine are subjected to periodic airflow excitation, which affects the blade fatigue life to a large extent. Based on the control stage model, the optimized chamber structure was proposed to reduce the local aerodynamic exciting force in the previous research. However, the local aerodynamic exciting force was not significantly reduced in the nozzle group linking-up section. Therefore, a novel chamber structure by adding flow cavity at nozzle group linking-up section is proposed to effectively suppress the local aerodynamic exciting force. The three-dimensional unsteady numerical method is employed to analyze the flow parameters of the cascade and the variation of unsteady aerodynamic exciting force. The feasibility and superiority of the proposed novel chamber structure are explained from the flow mechanism. The simulation results show that the high-speed flow caused by the narrow flow space in the nozzle group linking-up section is greatly reduced. Thus, enabling the relief of the pressure sudden change and the promotion of pressure in the low-pressure zone. The local axial aerodynamic exciting force is reduced by up to 59.4%. Meanwhile, the novel chamber structure reduces the rotor inlet pressure value from the block section to the inlet section of the nozzle group linking-up section. The local axial aerodynamic exciting force is reduced by 6.8%. In addition, it is worth noting that the novel chamber structure does not have an obvious impact on the aerodynamic performance. The relative change of efficiency is only 0.91%. From the verification results, it is evident that the novel chamber structure can effectively reduce the local aerodynamic exciting force in the nozzle group linking-up section.

部分进气可以确保涡轮机单元的高效运行，同时调节空气动力学负载。由于其优点，它具有广泛的应用前景。然而，部分进气涡轮的转子叶片受到周期性的气流激励，这在很大程度上影响叶片的疲劳寿命。基于控制级模型，在先前的研究中提出了优化的腔室结构以减小局部空气动力激振力。但是，在喷嘴组的连接部分中，局部空气动力激励力并未显着降低。因此，提出了一种通过在喷嘴组的连接部分增加流动腔的新型腔室结构，以有效地抑制局部空气动力。采用三维非稳态数值方法分析了叶栅的流动参数和非稳态气动激振力的变化。从流动机理解释了所提出的新颖腔室结构的可行性和优越性。仿真结果表明，喷嘴组连接段中狭窄的流动空间所引起的高速流动被大大降低。因此，能够缓解压力突然变化并提高低压区域中的压力。局部轴向空气动力激振力降低了多达59.4％。同时，新颖的腔室结构减小了从喷嘴组连接部分的块部分到入口部分的转子入口压力值。局部轴向空气动力激振力降低了6.8％。此外，值得注意的是，新颖的腔室结构对空气动力性能没有明显的影响。效率的相对变化仅为0.91％。从验证结果可以看出，新颖的腔室结构可以有效地减小喷嘴组连接部分中的局部空气动力。