A New Instability of Miscible Fluid Flows in the Stokes Regime: Linear Analysis and Direct Numerical Simulations

提案编号：CTS-0456722项目调查员：E.MEIBURGING INSTUTUTION：UNIV.加州大学圣巴拉特分校资助的研究人员将使用分析和计算工具来研究和记录两种可混溶流体在低Re时的不稳定性，以及垂直和倾斜管内密度和粘度的环状分层。最近的研究揭示了一个令人惊讶的结果：根据线性稳定性分析，与不相容的流体相比，可混相的流体是不稳定的。这就提出了关于混相和不混相界面流体动力学之间关系的基本问题，它们通常被认为表现出相应的不稳定性。根据这笔赠款，将继续对线性稳定性进行初步研究，并将进行直接数值模拟(DNS)研究，以探索非线性不稳定性。这项拟议工作的优点是它研究了最近发现的和潜在的重要的流体力学基本兴趣的不稳定性。对于化工、制药和石油工业中的许多过程来说，预测变粘度和密度混相流体流动行为的能力是很重要的。低雷诺数流动与微流体在生物医学和空间领域的应用特别相关。参与这项研究的学生将受益于他们参与UCSB正在进行的NSF IGERT计算科学与工程项目。PI在Prairie View A&amp；M大学的服务有力地证明了他们在研究生招生和教育方面致力于多样化的承诺。外国交换生积极参与研究将加强这项工作的传播。

PROPOSAL NO.: CTS-0456722PRINCIPAL INVESTIGATOR: E. MEIBURGINSTITUTION: UNIV. OF CALIFORNIA SANTA BARBARAThe researchers funded under this grant will use analytical and computational tools to investigate and document the instability of two miscible fluids at low Re with annular stratification of density and viscosity in vertical and inclined tubes. Recent research has revealed the surprising result that miscible fluids, in contrast to their immiscible counterparts, are unstable according to linear stability analysis. This raises fundamental questions regarding the relationship between miscible and immiscible interfacial fluid dynamics, which are often assumed to display corresponding instabilities. Preliminary investigations of linear stability will be continued under this grant, and direct numerical simulation (DNS) studies will explore nonlinear instability. The merit of the proposed work is its investigation of this recently identified and potentially important instability of fundamental interest in fluid mechanics. The ability to predict behavior of variable viscosity and density miscible fluid flows is important for a host of processes in the chemical, pharmaceutical and oil industries. Low Reynolds number flows are particularly relevant to microfluidics applications in the biomedical and space areas. Students involved in this research will benefit by their participation with an ongoing NSF IGERT program in Computational Science and Engineering at UCSB. The PI's service at Prairie View A&M University gives strong evidence of a commitment to diversity in graduate student recruitment and education. The active involvement of foreign exchange students in research will enhance dissemination of the work.