Numerical simulation study on wall interference of multi-size wind tunnel

Abstract

Wind tunnel experiment plays a very important role in the development of aircraft, but the existence of wind tunnel wall has a significant interference effect on the aerodynamic characteristics of aircraft, so it is necessary to do relevant research on the interference of tunnel wall. According to the characteristics of wind tunnel experiment, the flow field of a standard model in unsupported state in medium-sized wind tunnel open test section, medium-sized wind tunnel closed test section, large-sized wind tunnel closed test section and free flow field is numerically simulated By analyzing the variation of lift coefficient interference and drag coefficient interference with angle of attack, the following conclusions are obtained: the lift interference laws of the two sizes of closed wind tunnels are similar, and the interference increases with the increase of angle of attack, reaching the maximum when the angle of attack is 60 degrees, and then decreasing after the angle of attack is 60 degrees, and the lift interference of the open wind tunnel is the smallest, and the maximum appears at the angle of attack of 80 degrees. The law of resistance interference in closed wind tunnels with two sizes is similar, and the interference amount increases with the increase of angle of attack, while the resistance interference amount in open wind tunnels is the smallest. The outer boundary of the main flow area in the upstream of the aircraft is basically the same at different angles of attack, and in the downstream of the aircraft, the outer boundary of the main flow area gradually increases with the increase of angle of attack.