Investigation Of Flow Characteristics In Transonic Wind Tunnel With Porous Wall

In order to meet the modern advanced aircraft design requirements for high maneuver flight performance, wind tunnel test should provide more accurate data.Wall interference is an important factor to affect the accuracy of the transonic wind tunnel test data. At present, the vast majority of tunnel wall interference correction method will use the wall boundary conditions, and the accuracy of wall boundary conditions often directly determines the accuracy of the correction results. This paper takes the transonic wind tunnel wall boundary conditions as the starting point of the research work, the wall surface flow characteristics of transonic wind tunnel with porous wall are studied in detail by using numerical simulation method. Based on summing up the flow law of single hole, porous wall flow model which combines with the relevant flow theory is established. In the present work, firstly the research of the whole porous wall was simplified as study on the flow law of single hole, thus the difficulty of this research work was greatly simplified. Then the simplified geometry model was obtained according to the layout and related dimensions of FL-3 transonic wind tunnel test section, multi block structure grid was generated using Pointwise mesh generation software and determined the appropriate boundary conditions for calculation. Based on current calculation model, the flow field inside and near the hole was simulated by the method of CFD. The comparison with Nambu’s experimental and computational results verified the feasibility and correctness of calculation model and calculating method. Thus in this paper we considered both sides of the hole’s pressure difference, free flow Mach number, the boundary layer displacement thickness of the test section and hole’s depth diameter ratio influenced the flow of inside and near the hole, then summed up wall flow characteristics of the transonic wind tunnel with porous wall by a large number of qualitative and quantitative analysis, and combined with the relevant flow theory to establish porous wall flow model, the model can be used to simulate transonic wind tunnel wall boundary condition.