GEOMETRIC SENSITIVITY OF THREE-DIMENSIONAL SEPARATED FLOWS

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 流动包括强烈的逆压梯度和与光滑壁面分离的边界层(而不是固定在几何不连续处的分离)，属于最具挑战性的高雷诺数流动。分离点的准确预测对湍流模型提出了很高的要求，分离位置的微小误差会对整个速度和压力分布产生很大的误差。最终的结果是，CFD尚未在高负荷泵和在远离设计条件下运行的空气/水翼等系统的设计方面取得重大进展。本研究的目的是为在光滑的壁上形成的几何简单的扩散器几何形状的三维闭合分离气泡提供详细的数据集。此外，实验程序还与建模工作相结合。通过并行进行实验和模拟，我们可以确保在给模拟带来最大困难的流动区域提供最详细的数据。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Flows including strong adverse pressure gradient and boundary layer separation from a smooth wall (as opposed to separation fixed at a geometric discontinuity) are among the most challenging high-Reynolds number flows to model. Accurate prediction of the separation point puts great demands on turbulence models, and small errors in separation location can produce large errors in the overall velocity and pressure distribution. The end result is that CFD has not yet made significant inroads into the design of systems like highly loaded pumps and air/hydrofoils operating at far-off-design conditions. The objective of this research is to provide a detailed data set for a three-dimensional, closed separation bubble formed on a smooth wall in a geometrically-simple diffuser geometry. In addition, the experimental program is coupled to a modeling effort. By doing the experiments and simulations in parallel, we can assure that the most detailed data are supplied in the flow regions causing the most difficulties for simulations.