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本文介绍再入飞行器可能的最佳外形的研究情况。选择再入飞行器最佳形状的准则是:气动稳定性、端头和截锥体边界层转捩的发生和传播、非对称端头形状变化引起的配平、最小的再入散布以及助推器的尺寸和重量限制。数值计算结果表明,根据上述准则,与球形端头相比,扁圆形端头(例如平面端头或5×1椭球形端头)具有较好的潜在性能。对于后体,只考虑了双锥外形,并且经研究确定最佳的双锥外形有如下特点:θ_1≈2θ_2和R_b≈2R_i,其中θ_1,θ_2分别为前后锥的半锥角,R_i是双锥连接处的当地半径,R_b是再入飞行器的底部半径。在这些约束条件下,有可能在截锥体边界层转捩性能不降低的条件下,改善再入飞行器的气动热力学性能,例如x_(c·p),随M_∞和α的变化小;烧蚀端头对下游的影响降到最小。本文也对文中提出的再入飞行器最佳外形的缺点进行了讨论。
This article presents a study of the best possible shape for reentry aircraft. The criteria for selecting the best shape for reentry aircraft are: aerodynamic stability, the occurrence and propagation of tip and frustum boundary layer transitions, trim due to asymmetric tip shape changes, minimal rewetting, Size and weight limit. The numerical results show that, according to the above criteria, the oblate tip (eg, flat tip or 5 × 1 ellipsoid tip) has better potential performance than the spherical tip. For the rear body, only the double cone shape is considered, and the best double cone shape is confirmed by the research as follows: θ_1 ≈ 2θ_2 and R_b ≈ 2R_i, where θ_1 and θ_2 are the half cone angles of the front and the rear cone, respectively, and R_i is the double cone The local radius at the junction, R_b is the radius at the bottom of the reentry vehicle. Under these constraints, it is possible to improve the aerodynamic properties of the reentry vehicle, such as x_ (c · p), with small changes in M_∞ and α, under the condition that the performance of the truncated cone boundary layer is not reduced. The effect of etch tips on the downstream is minimized. This paper also discusses the shortcomings of the best shape of reentry vehicle proposed in this paper.