摘要
尖拱和钝拱细长体的截面侧向力分布呈现明显的滚转角效应。不同滚转角下尖拱侧向力沿轴向分布曲线(CC～x/D)的相位和半周期各不相同,截面侧向力随滚转角变化(CC～)呈现一定的无规律性;而钝拱CC～x/D曲线的相位和半周期基本相同,但振幅值大小依赖于滚转角,CC～分布呈完全的无规律性。尖拱模型头部的加工精度导致的微扰动使得尖拱CC～x/D分布变成型式基本一致的两簇曲线,其特征点和半周期分别对应相同,CC～分布呈现典型的双周期方波。
Roll angle effects of slender bodies with three different noses are experimentally studied at high angles of attack. The side force distributions (C_C～x/D) over the pointed-nose slender (model Ι) are greatly affected by the roll angle () with different curve phases and half-cycles. The sectional side force distributions vs the roll angle (C_C～) show some randomicity. While the curves C_C～x/D over another pointed-nose slender (model ΙΙ) turn into two curve clusters with nearly the same curve phases and half-cycles, and the curves of C_C～ show a typical bistable state. The two pointed-nose models are designed with exactly the same geometry, and are machined at the same time by encoded control except that model Ⅱ has micro-imperfectness at the nose tip due to the mismachining tolerance. But the curves C_C～x/D over the blunted-nose slender are not affected by basically, with same curve phases and half-cycles, and the curves C_C～ show complete randomicity.
出处
《实验流体力学》
EI
CAS
CSCD
北大核心
2004年第4期11-14,19,共5页
Journal of Experiments in Fluid Mechanics
关键词
细长旋成体
大迎角
非对称
滚转角效应
双稳态
slender body
asymmetric vortices
roll angle effect
bistable state
high angle of attack aerodynamics
