The aircraft wake vortex is an important factor affecting flight safety; as an important part of the aircraft, the powered nacelle will inevitably have an important impact on the aircraft wake vortex, so it is of great practical significance to research it. The present study focused on the numerical simulation of the wake flow of large aircraft (as the front aircraft) and the comparative analysis of the influence of engine jets on the wake flow. In order to meet the accuracy requirements and control the consumption of computing resources, LES and RANS methods were compared, and the RANS method was finally selected for subsequent calculation. The dynamic effect of jet flow was simulated by simplifying the boundary conditions of the inlet fan and outlet bypass as the mass flow boundary condition. The simulation results showed that the engine nacelle will have a significant impact on the morphology of the aircraft wake flow (position and strength of the main vortex in the wake flow system), which is caused by the vortices formed under the shear flow and separated flow of the nacelle. However, the nacelle will not significantly change the total strength of the wake vortex (half-plane circulation). The engine jet intensity causes additional turbulent mixing, which will accelerate the fusion of the nacelle vortex and ultimately change the intensity ratio of the inner wing vortex and the wingtip vortex, affecting the trajectory of the wake of the mean vortex. The study provides a corresponding reference for the following research on a wake vortex by a powered nacelle.

To me To meet the high-precision requirement for high-pressure gas supply flow control in wind tunnel testing, this paper proposes a high-resolution digital valve system based on a combination of a critical flow Venturi nozzle array and binary on-off valves. By decomposing the total throat area according to a binary pattern and using on-off valves to control the combination of nozzles of different sizes, the system achieves high-resolution and wide-range flow regulation from the minimum throat area to the total throat area. Experimental verification shows that the system achieves a control accuracy better than ±3 g/s within a flow range of 0.1 kg/s to 3.1 kg/s, with a response time shorter than 30 seconds, significantly outperforming traditional analog valves. This design provides an effective solution for powered simulation wind tunnel tests and other fields requiring high-precision high-pressure gas flow control.