NSF Young Investigator

摘要CTS-9457014明尼苏达大学P.I.： 埃伦·朗迈尔 明年的研究将包括实验流体力学领域的几个项目：固体表面附近的颗粒湍流相互作用，模型下击暴流的研究，后缘几何形状对射流混合的影响，以及流动结构对液体喷雾的影响。 在第一组实验中，我们研究的是颗粒在轻载冲击射流中的运动。 粒子图像和粒子跟踪测速技术被用来测量粒子的速度和轨迹存在的相干涡的已知规模。 高颗粒质量负载的单独实验将试图检查颗粒的湍流修改和冲击表面被加热时产生的任何传热修改。 在下击暴流研究中，我们将用PIV获得水平速度场，以检查方位不稳定性和近地面速度梯度的发展。 在射流研究中，我们将进行流动显示和速度测量，以了解参数对具有阶梯形和锯齿形后缘的圆形射流中混合的影响。 最后，我们将设计和建造一个设施，用于研究喷雾受到不同的湍流水平和结构。

ABSTRACT CTS-9457014 University of Minnesota P.I.: Ellen Longmire This research over the next year will include several projects in the field of experimental fluid mechanics: Particle-turbulence interaction near solid surfaces, investigation of model downbursts, effects of trailing edge geometry on jet mixing, and the effect of flow structure on liquid sprays. In the first set of experiments, we are examining the motion of particles in a lightly-laden impinging jet. Particle image and particle tracking velocimetry are use to measure particle velocities and trajectories in the presence of coherent vortices of known scale. Separate experiments with high particle mass loadings will attempt to examine turbulence modification by the particles and any resulting heat transfer modification when the impingement surface is heated. In the downburst study, we will obtain horizontal velocity fields with PIV to examine both the development of azimuthal instabilities and near-ground velocity gradients. In the jet study, we will perform flow visualization and velocity measurements to understand parametric effects on mixing in round jets with stepped and sawtooth trailing edges. Finally, we will design and construct a facility for the study of sprays subject to varying turbulence level and structure.