Experimental and numerical study on aerodynamic stability of compressor L-inlet duct

Total pressure loss and vortex pair are the two independent flow phenomena that affect the flow quality at the compressor L-inlet duct (CLID). Both flow phenomena do affect the compressor efficiency, aerodynamic stability and surge margin. However, no general report on the control of the two flow phenomena is found in the open literature. Therefore, in this study, a wind tunnel test bench is independently built to undertake the optical diagnostic test research of the CLID internal flow. Then, the internal flow in CLID is investigated with both the Particle Image Velocimetry (PIV) test and the numerical simulation. Furthermore, the effects of typical parameters on the CLID aerodynamic stability are investigated. Finally, based on the parametric sensitivity analysis, an orthogonal design method with array L16(45) is adopted to achieve the optimized CLID aerodynamic design. Results show that the designed wind tunnel test bench can successfully carry out the PIV test, and the test error is controlled below 1.5%. PIV test results show that two counter rotating vortex pairs are generated at compressor inlet case annular section P-a4 (q) = 180 degrees) and P-a5 (q) = 225 degrees). They are believed to affect the compressor surge margin. SC60 is validated to capture the vortex pairs, DC60 is validated to capture the total pressure loss. The larger the width (a/D4), depth (b/D4) and cone diameter (D0/D4), the better the CLID aerodynamic stability. The optimized CLID aerodynamic design is achieved by the L16(45) orthogonal design.(c) 2023 Elsevier Masson SAS. All rights reserved.

Automated summary

Total pressure loss and vortex pair are two independent flow phenomena that affect the flow quality at the compressor L-inlet duct (CLID), and they have impacts on compressor efficiency, aerodynamic stability, and surge margin. However, there is no general report on controlling these flow phenomena in the open literature. In this study, a wind tunnel test bench is built to investigate the CLID internal flow using both Particle Image Velocimetry (PIV) and numerical simulation. The effects of various parameters on CLID aerodynamic stability are examined, and an optimized design is achieved through parametric sensitivity analysis and orthogonal design methods.