Ventral support interference in low-speed and high Reynolds number wind tunnel

For the problem of the ventral support interference in the FL-9 low-speed and high-Reynolds number wind tunnel, series comparative tests were conducted regarding various supports with different configurations including circle shape and twenty-four sides polygon, cone shape and constant section shape, different diameter ratios of the fuselage and the strut. These experiments were employed to study the selection rule for the FL-9 wind tunnel internal balance mono-strut ventral support with respect to the two-dimensional cross section shape, the three-dimensional spatial shape, and the strut diameter. A strut insensible to Reynolds number was obtained with low and stable support interference. The repeatable precision and accuracy of the FL-9 wind tunnel internal balance mono-strut ventral system were further verified by comparing the present tests with those conducted in other wind tunnels.