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

University Of California-Santa Barbara, Santa Barbara CA

Investigators

Abstract

PROPOSAL NO.: CTS-0456722 PRINCIPAL INVESTIGATOR: E. MEIBURG INSTITUTION: UNIV. OF CALIFORNIA SANTA BARBARA The 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.