Large eddy simulations (LESs) were conducted to investigate the separated flow transition process over two compressor blades with different loading distributions at Reynolds numbers (Re) of 1.5×10⁵ and 0.8×10⁵. The baseline airfoil (V103-B) was redesigned to obtain a new front-loaded airfoil (V103-F). At Re=1.5×10⁵, a time-averaged laminar separation bubble (LSB) formed on the suction surface of V103-B and V103-F. The two-dimensional spanwise vortices shed periodically at approximately the same frequency and were further twisted through their interaction with the streamwise evolving vortices. Then, small vortex structures were generated in the vortex pairing, which was related to the onset of transition. The distorted hairpin vortices finally broke down into small turbulent eddies near the reattachment, along with an ejection-sweeping process of the near-wall flow. As Re decreased to 0.8×10⁵, the separated shear layer failed to reattach on the blade surfaces of the two airfoils. The near-wall flow ejection-sweeping disappeared, and there was no distinct periodicity for the two-dimensional spanwise vortex shedding. The spectral analysis indicated that the transition processes in the LSBs of the two airfoils at Re=1.5×10⁵ were both dominated by the Kelvin-Helmholtz (K-H) mechanism; however, the transition onset on the suction surface of V103-F was promoted, and the size of LSB was consequently smaller than that of V103-B. The loss generation mechanism in the LSB was analyzed by comparing the deformation work terms due to the viscous and turbulent dissipation effects, with the results indicating that the largest amount of loss was determined by the Reynolds shear stresses. Due to the suppression of the LSB on the suction surface of V103-F, the profile loss was decreased distinctly by 32.3% at Re=1.5×10⁵ compared with that of V103-B.

进行了大涡模拟（LESs），以研究雷诺数（Re）为1.5×10 ⁵和0.8×10 ^5的两个具有不同载荷分布的压缩机叶片上的分离流动过渡过程。重新设计了基准翼型（V103-B），以获得新的前载翼型（V103-F）。在Re = 1.5×10 ^5时，是在V103-B和V103-F的吸力面上形成的时均层流分离气泡（LSB）。二维翼展方向涡流周期性地以大致相同的频率掉落，并通过它们与沿流方向发展的涡流的相互作用而进一步扭曲。然后，在涡旋配对中产生了小的涡旋结构，这与过渡的开始有关。扭曲的发夹涡流最终在重新连接附近分解成小的湍流涡流，以及近壁流的喷射扫掠过程。当Re降至0.8×10 ^5时，分离的剪切层无法重新附着在两个机翼的叶片表面上。近壁流喷射扫掠消失了，二维展向涡旋脱落没有明显的周期性。光谱分析表明，在Re = 1.5×10 ^5时，两个机翼的LSBs发生过渡。两者均由开尔文-亥姆霍兹（KH）机制主导；但是，促进了V103-F在吸力表面上的过渡转变，因此LSB的尺寸小于V103-B的尺寸。通过比较由于粘性和湍流耗散效应引起的变形功项，分析了LSB中的损耗产生机理，结果表明，最大的损耗量是由雷诺剪切应力决定的。由于抑制了V103-F的吸力表面上的LSB ，与V103-B相比，在Re = 1.5×10 ^5时，轮廓损失明显减少了32.3％。