NSF Young Investigator

未来一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，模型下爆的研究，尾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，我们正在研究轻载荷撞击射流中粒子的运动。粒子图像和粒子跟踪测速技术用于测量已知尺度的相干涡旋存在下的粒子速度和轨迹。高颗粒质量负荷的单独实验将试图检验颗粒对湍流的改变以及当撞击表面被加热时产生的传热改变。在降爆研究中，我们将利用PIV获得水平速度场，以检查方位角不稳定性和近地速度梯度的发展。在射流研究中，我们将进行流动可视化和速度测量，以了解参数对阶梯状和锯齿状尾缘圆形射流混合的影响。最后，我们将设计和建造一个设施，用于研究不同湍流水平和结构的喷雾。

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.