Experimental and Numerical Investigation on the Aerodynamic Performance of a Compressor Cascade Using Blended Blade and End Wall

Abstract

Nowadays, the corner separation, occurring near the corner region formed by the suction surface of blade and end wall, has been an important limitation for the increasing of the aerodynamic loading in the compressor. The previous numerical studies indicate that the Blended Blade and End Wall (BBEW) technology is useful in delaying, or reducing, or even eliminating the corner separation. To further validate the concept, this paper presents combined experimental and numerical investigations on a BBEW cascade and its prototype. Firstly, the NACA65 linear compressor cascade with the turning angle 42 degrees was designed and tested in a low-speed wind tunnel. Then, the cascade with blended blade and end wall design was made and tested in the same wind tunnel. The experimental results show that the design of blended blade and end wall can improve the performance of the cascade when the incidence angle was positive or at the design point, and the total pressure loss coefficient was reduced by 7%–8%. The performance improvement mainly located from 10%–25% span heights. Secondly, based on the experimental data, the numerical study made by our internal code Turbo-CFD shows the difference of the simulation precision of the results, obtained from four different turbulence model after the mesh independence test. The four turbulence model is Spalart-Allmaras model, standard k-ε model, standard k-ω model, and shear stress transport k-ω model. For this case, the SST turbulence model has better performance compared with others. Thirdly, based on the results which were calculated with the turbulence model SST, the effect of the blended blade and end wall design was discussed. The numerical study shows that the design with the blended blade and end wall can have a good effect on the corner flow of the cascade. The strong three-dimensional corner separation, caused by the accumulation of the flow happening at the trail of the suction side was avoided, and the flow losses of the prototype cascade were reduced. Above all, the experiment shows that the design with blended blade and end wall can improve the performance of the cascade. Compared with the experiment data, the SST turbulence model shows the best results of the flow field. Based on the numerical results, the details of the flow field and the effect of the blended blade and end wall design on the corner separation are discussed and analyzed.

Large Eddy Simulation of Corner Stall Control in a Linear Compressor Cascade by Blended Blade and Endwall Technique

“…Finally, A curved surface is constructed connecting all of the new blade profile, and the BBEW cascade geometry is output. Figure 4 Schematic definition of the BBEW parameters [17]. A sensitivity analysis of the important parameters of the BBEW technique indicates that both the chord-direction position of the maximum BBEW width XS and the maximum BBEW width YS on the blade suction side have a significant effect on the aerodynamic performance of a BBEW cascade [17].…”

“…Figure 3 Process of BBEW modeling [17].Figure4Schematic definition of the BBEW parameters[17]. A sensitivity analysis of the important parameters of the BBEW technique indicates that both the chord-direction position of the maximum BBEW width XS and the maximum BBEW width YS on the blade suction side have a significant effect on the aerodynamic performance of a BBEW cascade[17]. In addition, it should be noted that the aerodynamic performance of a compressor cascade can hardly be improved by the BBEW design on the pressure side.…”

Control and Entropy Analysis of Corner Flow Separation in a Compressor Cascade Using Streamwise Grooves

“…The airfoil sketch and solid model are shown in Figure 1 . More detail information about this cascade can be found in References [ 35 , 36 ].…”

Novel Optimization Design Methods of Highly Loaded Compressor Cascades Considering Endwall Effect

“…As the compressor load increases, the boundary layer near the endwall grows rapidly, which can lead to significant secondary flow loss and flow blockage and bring a significant impact on aerodynamic performance [ 20 ]. So far, many flow control methods have been proposed by scholars to improve the flow field near the endwall [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. From previous research, we can find that it is of great significance to improve the flow field near the endwall by applying bowed blade modeling methods [ 20 , 21 , 25 , 27 , 28 ] and endwall blade modeling methods [ 20 , 22 , 23 , 24 , 25 ] in the blade design of highly loaded compressors.…”

“…So far, many flow control methods have been proposed by scholars to improve the flow field near the endwall [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ]. From previous research, we can find that it is of great significance to improve the flow field near the endwall by applying bowed blade modeling methods [ 20 , 21 , 25 , 27 , 28 ] and endwall blade modeling methods [ 20 , 22 , 23 , 24 , 25 ] in the blade design of highly loaded compressors.…”