# Toward the Utilization of 3D Blading in the Cantilevered Stator from Highly Loaded Compressors
## 5 Conclusions  
This study focuses on the utilization of 3D blading in the cantilevered stator and seeks to reveal its mechanism in improving the compressor aerodynamic performance. The main conclusions are drawn as follows:  
1. The forward sweep can inhibit the transverse flow near the hub endwall and alleviate the flow separation at the corner region, while flow separation on the blade suction side was exaggerated slightly. Increasing the sweep height facilitates a uniform separation along the span without changing the endwall flow significantly, whereas excessively large sweep angles lead to a large-scale separation on the blade suction surface and harm the total effect;
2. The positive dihedral not only pushes the trajectory of the leakage vortex away from the blade suction surface but also promotes the radial migration of the low-energy fluid at the hub corner. The utilization of large dihedral heights elongates the blade wake and induces the radial transportation of the leakage flow, while the excessive dihedral angle damages the performance at the midspan;
3. The compound forward sweep and positive dihedral can combine the advantages of both strategies and provide better aerodynamic performance for the cantilevered stator, the benefit extends over the whole operating range and is more significant at lower mass flow ratios. In comparison to the orthogonal stator, the static pressure rise coefficient and the total pressure loss coefficient of the 3D bladed stator are increased and decreased by 25.5% and 11.1%, respectively;
4. The compound sweep and dihedral were utilized to redesign a cantilevered stator in a low-speed compressor test facility. Experimental results demonstrate that the total pressure loss of the 3D cantilevered stator is reduced by 20.5% at the near-stall point, thus proving the effectiveness of the 3D blading technique. The advantage of 3D blading is more pronounced at small mass flow coefficients;
5. The performance enhancement of the 3D blading stems mainly from the hub and lower span areas. At large mass flow ratios, the leakage flow leaks into the adjacent blade channel and causes secondary loss, yet at small mass flow rates, the inhibition  
Figure 37: Distribution of secondary flow velocity vector at the stator outlet.  
of the leakage flow to the endwall secondary flow is not strong enough; hence, the corner separation needs further elimination. The design of the 3D cantilevered stator needs to optimize the evolution of corner flow structures over the operating range.  
The validation of the 3D blading is conducted in the low-speed compressor test facility under the single-stage environment in the present study, and it would be meaningful if experiments could be implemented in high-speed and multi-stage environments in the future to reveal more flow mechanisms while validating the present conclusions.  
Conceptualization, G.A. and X.Y.; methodology, X.X., R.W. and G.A.; software, G.A.; validation, Y.Q., G.A. and X.Y.; formal analysis, X.X., R.W. and G.A.; investigation, X.X., Y.Q., R.W., B.L., G.A. and X.Y.; resources, Y.Q. and G.A.; data curation, Y.Q., X.X., R.W. and G.A.; writing--original draft preparation, X.X. and R.W.; writing--review and editing, R.W.; visualization, Y.Q., X.X. and R.W.; supervision, B.L.; project administration, B.L. and X.Y.; funding acquisition, B.L. All authors have read and agreed to the published version of the manuscript.  
This research was funded by National Natural Science Foundation of China (Grant Nos. 52276025, 52206038), the National Science and Technology Major Project (J2019-II-0004-0024, J2019-II-0003-0023), the Advanced Jet Propulsion Innovation Center / AEAC (funding number HKCX2022-01-008), and the Fundamental Research Funds for the Central Universities.  
Not applicable.  
The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.  
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