尾翼の縱搖れモーメントに及ぼす風洞境界の影響

概要

論文の詳細を見る
The Boundary Influence. of a Circular Wind Tunnel on the Pitching Moment of the Tailplane [Journal of the Aeronautical Research Institute, Tokyo Imperial University, No. 141, May, 1936].-The present paper considers the boundary influence experienced by the tailplane of a model aeroplane in a circular wind tunnel. Expressing the angle of interference experienced by the main plane in the form Δα=δ(S/πa^2)c_z, where S is the wing area, a the radius of the tunnel, and c_z the lift coefficient, the interference experienced by the tailplane, situated downstream aξ behind the main plane, is given by (I+τ)Δχ in a tunnel with open working section and (I+τ*)Δα in a tunnel with closed working section. τ and τ*, which represent the additional interference, are calculated by making use of Burgers' solution (Durand's Aerodynamic Theory, Vol. 2) and are shown in Figs. 2 and 3. In Fig. 2 is also shown the value of τ* due to Lotz (Luftfahrtforschung Bd. 12, Nr. 8,1935) by a broken line, which is about ten per cent larger than that obtained by the present writers. As a consequence of the additional interference the value of pitching moment qSt_mc_m of a model aeroplane obtained from tests requires the correction Δc_m=(dcm'/dβ)Δβ, where q is the dynamic pressure, t_m the mean chord, cm' the uncorrected moment coefficient, and Δβ equal to τΔα (open) or τ*Δα (closed). In most practical cases it is sufficiently accurate to take [numerical formula] where lH is the distance of tailplane from the point about which the moment is referred to, and S_H and b_H are the area and the span of the tailplane respectively. Since Δα is a downwash in a tunnel with open working section and an upwash in a tunnel with closed working section, it appears that the pitching moment is measured too small in the former and too large in the latter case.
宇宙航空研究開発機構の論文

尾翼の縱搖れモーメントに及ぼす風洞境界の影響

スポンサーリンク

概要

宇宙航空研究開発機構 | 論文

スポンサーリンク