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

建议没有。项目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低Re下具有密度和粘度环形分层的垂直和倾斜管中的混相流体的不稳定性。最近的研究揭示了一个令人惊讶的结果，即根据线性稳定性分析，与非混相流体相比，混相流体是不稳定的。这就提出了关于混相和非混相界面流体动力学之间关系的基本问题，这通常被认为表现出相应的不稳定性。线性稳定性的初步研究将在这笔拨款下继续进行，直接数值模拟（DNS）研究将探索非线性不稳定性。这项工作的优点在于它对流体力学中最近发现的、潜在的重要不稳定性的研究。预测变粘度和密度的可混相流体流动行为的能力对于化工、制药和石油工业的许多过程都很重要。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通过参与正在进行的UCSB计算科学与工程NSF IGERT项目而受益。在Prairie View A&amp；M大学的PI服务提供了强有力的证据，证明了研究生招生和教育的多样性。外国交换学生积极参与研究，可促进研究成果的传播。

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.