Flow and Performance of Airfoils in Air-Water Two-Phase Flow

作为对涡轮机械的两个阶段流动性能、两个阶段流动的基本研究，围绕空气/水条件下的两个阶段流动和瀑布，是从实验和理论上研究的。结果按以下顺序汇总：1。用测试部分200 × 100毫米，最大200毫米/2000毫米/200毫米/2000毫米/20000毫米/200毫米/2000000毫米/200毫米/2000毫米/200速度为8米/秒，马斯。10%的部分是设计和建造的。由于没有类似的测试隧道已经在其他地方建造，它需要几个测试和重新设计空气注射装置和缩小喷嘴，在一个满意的统一分布的空白片段出现在测试部分。空气被注入到减少喷嘴的水上游，通过9块薄刀片制成的盐际粉末金属。两种孤立的气垫和气垫层叠都可以在测试部分安装。局部空分数测量系统的开发该系统由点电探针组成， x-y自动遍历 ... More 设备和信号处理器。void分数和void大小的空间分布可以是可衡量的有效性。在两个阶段流动的空气油在NACA 4412空气油的攻击角度为0 - 15 °和0 - 10%的空分数。空分数的空间分布是由点电测量的。升降机和拖动特性是由空气油上的压力分布决定的。Due to the pressure gradient环绕着空气油，在这样一个比喻中，当泡沫累积在sucucumulate的一侧时，他们从压力一侧向外扩展。这给了一个不寻常的举重攻击角度的特征。数值模拟基于泡沫的动力学，流动场是公式化的基本方程，将泡沫和周围的水之间的滑动带入帐户。theory and experiment is still not complete and will be done in the near future。Study will be expanded to the case of cascade after the basic understanding is obtained on the two phase flow phenomena around an isolated airfoil。Less（低）

As a basic research of two phase flow performance of turbomachinery, twodimensional flow around an airfoil and cascade of airfoils in air/water two phase condition was studies experimentally and theoretically. The results are summarized as follows:1. Construction of two-phase flow water tunnel Air/water recirculating water tunnel with test section of 200x100 mm, max. velocity of 8 m/s, mas. void fraction of 10 % was designed and built. Since no similar test tunnel has been built elsewhere, it required several testing and redesign of air injection device and reducing nozzle, before a satisfactorily uniform distribution of void fraction was obtained at the test section . Air is injected to water upstream of the reducing nozzle through 9 thin blades made of sintered powder metal. Both isolated airfoil and cascade of airfoils can be installed in the test section.2. Development of measurement system for local void fraction The system is composed of point electrode probe, x-y auto-traversing … More device and signal processor. Spatial distribution of void fraction and void size can be measured efficiently.3. Flow around an airfoil in two phase Flow flow around a NACA 4412 airfoil was measured for attack angle of 0 - 15゜and void fraction of 0 - 10 %. The spatial distribution of void fraction was measured by point electrode. Lift and drag characteristics were determined from pressure distribution over the airfoil. Due to the pressure gradient around the airfoil, the redistribution of bubbles occurs in such manner that bubble accumulate on the suction side while they are expelled from the pressure side. This gives rise to an unusual lift-attack angle characteristics.4. Numerical simulation Based on the dynamics of bubbles the basic equations of flow field were formulated, taking the slip between bubbles and surrounding water into account. The direct comparison between theory and experiment is still not complete and will be done in the near future.The study will be expanded to the case of cascade after the basic understanding is obtained on the two phase flow phenomena around an isolated airfoil. Less