# The Investigation of a New End Wall Contouring Method for Axial Compressors
## 3 Application in a High-Load Compressor Cascade
### Results and Discussion
Therefore, it is more advantageous than case c1 here, and it can be seen from the TE plane's \(\mu_{t}/\mu\) contour that the local shear loss is more minor than case c1. The weight factor of the localized unit in case c3 is larger than that of case c2, so the control of pressure gradient in the upstream SS corner and the enhancement of secondary flow pre-mixing near the trailing edge are more significant than that of case c2. The loss reduction in case c3 is, therefore, more significant. The influence of end wall contouring at the near-stall point (\(i=7^{\circ}\)) is discussed similarly to the design point but more concisely. The flow field is shown in Figure 11b,d,f,h. Compared to the flow field in the design point, the differences between case c1 and the baseline case at the near-stall point are similar to those concluded at the design point. It also appears that the pressure gradient in the SS corner area from 0.2\(C_{\text{a}}\) to 0.4\(C_{\text{a}}\) increases significantly, the secondary climbing flow from the SS corner between 0.5\(C_{\text{a}}\) and TE weakens, and the streamwise pressure gradient near the TE of SS reduces. However, the main difference is that the corner separation at the LE of the cascade is much more severe than the design point (labeled using a dashed white circle in Figure 11d). The local pressure gradient increase due to the sinking end wall intensifies the reverse flow trend, making the corner separation stronger after its generation. This effect amplifies the negative impact of the end wall contouring on the flow field of the cascade between 0.2\(C_{\text{a}}\) and 0.4\(C_{\text{a}}\), finally leading to an overall loss increase. Thus the contour of \(\mu_{t}/\mu\) shows that the low-energy separation flow causes much higher shear losses than the baseline cascade when it develops to the TE. The advantages of cases c3 and c2 over case c1 are still significant. Under the influence of the localized unit, case c3 and case c2 show more mitigated upstream corner reverse flow and more intense downstream pre-mixing effect of the separation flow than case c1. Therefore, the control of separation loss in cases c2 and c3 is better than case c1. case c3 leads to the slightest increase in loss among all end wall contouring cases due to its larger weight factor of the localized unit than case c2. In summary, although the corner separation is still not effectively suppressed at the near-stall point, the new end wall contouring method shows its potential for flow control, especially when combined with the previous experience. As already mentioned at the beginning of Section 3, case c1 represents the DPS designed by the traditional empirical method. In comparison, the cases using two end wall contouring units perform better under more than one incidence. What's more, the intended flow control of the full-area and localized units, including the effect of their weight factors, agrees very well with their effects during the application. All these indicate that the new end wall contouring method is superior to the traditional empirical method.