# Influence of Active Flow Control of Synthetic Jet at
## 2 Research Object and Numerical Simulation Method
### Numerical Simulation Methods and Effectiveness  
Establish a single-channel computational domain from the radial inlet to approximately 5.7 times the chord length downstream of the rotor outlet, as presented in Figure 2. Use the IGG/AutoGrid5 module of NUMCA 16.1 software to divide grids. The entire computational domain grid is divided into two parts along the flow direction: the stationary region from the radial inlet to the leading edge of the rotor inlet, and the remaining region is the rotational region. The height of the first layer of the grid is set to 5 \(\times\) 10\({}^{-6}\) m, and the blade channel adopts an O4H-type grid topology. A total of 205 grid nodes are arranged around the blade, and 93 grid nodes are arranged along the blade's height. The blade tip gap adopts a butterfly grid topology, with 17 grid nodes arranged radially in the gap, and the remaining areas adopt an H-shaped grid topology. The entire computational domain grid is approximately 960,000, as presented in Figure 3.  
Using ANSYS CFX 18 software for single-channel calculation, the speed of the prototype compressor was set to 8130 r/min and 10,765 r/min, respectively, to compare with experimental results and verify the reliability of the numerical model. During the calculation process, the working fluid is set as an ideal gas, and the k-omega turbulence model is used to solve the three-dimensional Reynolds time-averaged N-S equation in a relative coordinate system. The spatial term is discretized using a second-order upwind difference scheme, while the temporal term is discretized using the fourth-order Runge-Kutta method. The mixed plane method is used for data transfer at the rotational and static interfaces. The inlet of the compressor is set to the total temperature and total pressure of the standard atmosphere, and the outlet is set to the average static pressure. Starting from low back  
Figure 3: Mesh and \(y+\) contour.  
Figure 2: Computational domain.  
pressure, gradually increase the back pressure until numerical convergence is not possible. At this point, it is also considered that the compressor is physically stalled, and the performance of the compressor with the last convergent back pressure before divergence is considered near-stall performance.  
Figure 4 presents a comparison of the total performance of the subsonic axial compressor rotor obtained from experimental measurements and numerical calculations. From the graph, it can be concluded that the near-stall flow rate, total pressure ratio, and efficiency obtained from numerical calculations are in good agreement with experimental measurements, but there are also certain errors, which may be related to factors such as ideal gas assumption and turbulence model selection during software settings. However, the overall trend of the parameters obtained from numerical prediction and experimental measurement is consistent, and the distribution of the total pressure ratio at the outlet of the three operating conditions of 8130 r/min presented in Figure 5 is also consistent with the experimental measurement results. Therefore, it can be considered that the numerical model established in this paper is reliable, and further research will be conducted on this basis.