Akademik Veri Yönetim Sistemi
10th ANKARA INTERNATIONAL AEROSPACE CONFERENCE, Ankara, Türkiye, 18 - 20 Eylül 2019
Aerodynamic design of a closed-circuit subsonic wind tunnel, with 7mx5m test section, is performed. The test section length is 18m. The design flow velocity in the test section is considered to be 100 m/s. The test section enlarges slightly in the flow direction to compensate boundary layer growth. An 8:1 contraction ratio is selected to obtain, as much as possible, uniform and low turbulence flow in the test section. The contraction cone angle is 30 and side surface geometries are obtained by using two third order polynomials. The diffuser sections of the tunnel have not more than 2.5 expansion angles to prevent flow separations. All the rectangular cross sections of the tunnel are cut by isosceles right triangles to obtain octagonal cross sections to eliminate losses and non-uniformities related to corners. An empirical study is performed to estimate losses in different components of the wind tunnel circuit. CFD studies are performed to visualize flow quality, determine the improvement areas and estimate losses.