Unsteady Crossflow Separation Location Measurements on a Maneuvering 6:1 Prolate Spheroid
Unsteady Crossflow Separation Location Measurements on a Maneuvering 6:1 Prolate Spheroid
复制标题
机动 6:1 长球体上的非稳态横流分离位置测量
DOI：
10.2514/2.307
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
R. Simpson
中科院分区：
文献类型：
--
作者：
T. G. Wetzel;R. Simpson
本文研究了6：1长椭球体作瞬态机动时的横流分离。动态倾翻-俯仰-滚转模型支架提供了在风洞中模拟非定常机动的独特能力。热膜传感器与恒温风速计一起用于测量整个模型表面上各点处随时间变化的壁面剪力。壁面剪力的最小值用于指示分离位置。给出了两种快速机动的定常和非定常数据：绕模型中心的0-30 °、0.33 s（t' = tU /L = 11）斜坡上仰（上仰机动）和绕模型中心的0-13.5 °、0.25 s（t' = 8.3）上仰（模拟潜艇进入转弯机动时随时间变化的侧滑角）（潜艇机动）。数据表明，特别是在大迎角时，机动过程中的流场与定常情况相比出现了明显的滞后。特别是，与定常数据相比，在非定常机动中，分离在模型的所有位置都被延迟了10 °以上的迎角。同样，非定常机动时的分离结构比定常数据滞后1.5 ~ 3.5个无量纲时间单位t'。
The crossflow separation of a 6:1 prolate spheroid undergoing transient maneuvers is studied. The dynamic plunge-pitch-roll model mount provides the unique capability to simulate unsteady maneuvers in a wind tunnel. Hot-film sensors are used with constant-temperature anemometers to measure the time-depcndent wall shear at points over the entire model surface. Minima in wall shear are used to indicate separation locations. Steady and unsteady data are presented for two fast maneuvers: a 0-30-deg, 0.33-s(t' = tU /L = 11) ramp pitchup about the model center (pitchup maneuver) and a 0-13.5-deg, 0.25-s (t' = 8.3) pitchup about the model center that simulates the time-dependent sideslip angle of a submarine entering a turning maneuver (submarine maneuver). Data show that, especially at higher angles of attack, significant lags occur in the flowfield during the maneuvers compared with the steady cases. In particular, separation is delayed at all locations of the model by up to a 10-deg higher angle of attack in the unsteady maneuvers compared with the steady data. Equivalently, the separation structure during the unsteady maneuvers lags the steady data by from 1.5 to 3.5 nondimensional time units t'