# Experimental and Numerical Research on End-Wall Flow Mechanism of High-Loading Tandem Stators
## 3 Loss Distribution of Tandem Stators
It experienced a steady decline as the flow coefficient reduced, with only a slight increase near the stall point. Moreover, the proportion of the FB loss consistently exceeded 60% across the entire operating range, reaching up to 70% near the stall point. This significant dominance of the FB loss decisively influenced the overall total loss of the tandem stator. The total loss of the stator was evaluated using mass flow averaging. However, to provide a more rational assessment of their relative significance, it was necessary to investigate the proportion of loss contributed by each part of the stator. The computational  
Figure 12: Extracted plane between FB and RB. Figure 13: Variation of the total pressure loss of FB and RB with the flow coefficient. process for determining the loss proportions in the blade root, middle, and tip regions was detailed in Appendix A. Figure 14 compared the total pressure loss and loss proportion across the three regions for both the FB and the RB. Similar to two-dimensional cascades, the FB experienced changes in stator incidence, and its loss variation in each region generally followed patterns observed in conventional blades. As the flow coefficient decreased, the total pressure loss at the blade root and tip initially dropped before increasing again, with a rapid escalation near-stall conditions in both end-wall regions. As depicted in Figure 14b, the loss proportion attributed to the root region of the FB constituted the largest portion of the overall loss, approximately 40%, followed by the tip and mid-span regions. This distribution underscores the pivotal role that the root region played in the overall performance and efficiency of the tandem stator. For the RB, the trend in total pressure loss was significantly different from that of conventional stators. As the flow coefficient decreased, the total pressure loss and the loss proportion in the root regions experienced a gradual decrease. However, within the mid-span region, the total pressure loss steadily increased, along with a corresponding gradual increase in its loss proportion. At low mass flow rates, the loss proportion of the mid-span region in the RB increased to more than 60%. It could be seen that the loss of tandem stator presented the following features:  
1. The variation in FB loss followed a pattern similar to that of conventional stators. And the FB loss accounted for a high proportion and played a decisive role in the total loss. 2. The variation in RB loss was significantly different from that of conventional stators. Specifically, the loss in the mid-span region of the RB steadily increased, with its proportion reaching over 60% near the stall condition. This highlights the pronounced impact on performance at low flow rates. 3. In contrast to general trends, the total pressure loss and loss proportion within the root regions of the RB gradually decreased. These loss characteristics of tandem stators were all related to the corresponding flow characteristics. The following work will focus on the three characteristics of loss distribution and development and reveal the essential mechanism of loss change.