At high Reynolds number, the flow of an incompressible fluid over a lifting surface is a rich blend of fluid dynamic phenomena, and the individual elements of this process have been the subject of much prior work. However, controlled experimental investigations of lifting surfaces at Reynolds numbers typical of heavy-lift aircraft wings or full-size ship propellers (chord-based Reynolds numbers, ReC ∼ 107–10 8) are largely unavailable. This paper presents experimental results from the flow over a two-dimensional hydrofoil at nominal ReC values from near one million (1M) to more than 50 million (50M). The tests were conducted in the U.S. Navy's William B. Morgan Large Cavitation Channel with a solid-bronze hydrofoil (2.1 m chord, 3.0 m span, 17 cm maximum thickness) at flow speeds from 0.25 to 18.3 m/s. The foil section, a modified NACA 0016 with a rounded trailing-edge bevel, approximates the cross section of a generic naval propeller blade. Trailing-edge geometries with bevel angles of 44° and 56° are investigated.; Flow field velocities are measured with laser Doppler velocimetry and planar particle imaging velocimetry. Pressure measurements are made with static pressure taps along the foil chord and test section walls and with unsteady pressure sensors near the trailing edge. Results are presented from the time-averaged flow (part I), as well as turbulence statistics, pressure and velocity spectra, and instantaneous velocity fields (part II). Geometry and Reynolds-number dependencies in the mean flow are linked to similar dependencies in the dynamic flow. A correlation is shown between the suction side time-average shear rate near the trailing edge and the strength of the near-wake vortex shedding. Peaks in spectra of vertical velocity fluctuations associated with vortex shedding near the trailing edge are strongest when the suction side shear layer, which separates upstream of the trailing edge, most effectively induces roll-up of the pressure side shear layer, which separates at the trailing edge. A scaling law based on the velocity induced by the suction side vorticity on the pressure side shear layer at the trailing edge collapses measurements of shedding strength on both trailing edge geometries for 1.4M ≤ ReC ≤ 50M.
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机译：在高雷诺数下，不可压缩流体在提升面上的流动是流体动力学现象的丰富混合，并且此过程的各个要素已成为许多先前工作的主题。但是，对重载飞机机翼或大型船舶螺旋桨的雷诺数（基于弦的雷诺数，Re 〜10 7 ）的升力面进行的受控实验研究–10 8 ）在很大程度上不可用。本文介绍了在标称Re 值从接近一百万（1M）到超过5,000万（50M）的二维水翼上流动的实验结果。测试是在美国海军的William B. Morgan大空化通道中进行的，该通道具有固体青铜水翼（弦长2.1 m，跨度3.0 m，最大厚度17 cm），流速为0.25至18.3 m / s。铝箔部分是经过修改的NACA 0016，具有圆滑的后缘斜面，近似于通用海军螺旋桨叶片的横截面。研究了斜角为44°和56°的后缘几何形状。用激光多普勒测速仪和平面粒子成像测速仪测量流场速度。压力测量是通过沿箔弦和测试段壁的静压接头以及在后缘附近的不稳定压力传感器进行的。结果来自时间平均流量（第一部分），湍流统计，压力和速度谱以及瞬时速度场（第二部分）。平均流中的几何和雷诺数依赖性与动态流中的类似依赖性相关。在后缘附近的吸力侧时间平均剪切速率与近尾涡流脱落强度之间显示出相关性。当在后缘上游分离的吸力侧剪切层最有效地引起在后缘分离的压力侧剪切层的卷起时，与后缘附近的涡旋脱落相关的垂直速度波动谱中的峰最强边缘。基于在后缘的压力侧剪切层上的吸力侧涡旋引起的速度的比例定律使1.4 M ≤Re C ≤50 M 。
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