Design of micronozzles and control of droplet sizes by a sensitivity analysis of the flow field

Research Area: Fluid mechanics
Project Members:
Tammisola, O.
Sponsor: VR 

Project Description

This project is funded by Swedish Science Council (VR) for 3.300.000 SEK. The aim of this project is to develop computational methods to understand and optimize flows in microfluidic devices. One goal is to enhance mixing through control of vortical structures, the other goal is to control droplet sizes. The research proposed is original work different from the researcher´s previous work. For many flows, transitions between different flow regimes can be identified and physically understood by a flow instability analysis. By different flow regimes are meant, for example, production of small vs. large droplets from an ink jet, or transition to three-dimensional vortices and enhanced mixing in a micromixer. Microfluidic flows often possess surface tension and/or complex viscosity due to the presence of particles, which is why stability analyses have not been performed for most of these flows. The work in this proposal will result in stability methods applicable for 3D microflows, with surface tension and complex viscosity. Further, the adjoint equations will be solved and used for gradient-based shape optimization. The flow geometry can be designed such that the flow remains in the desired flow regime, for example small droplets, for a wide range of operating conditions.

Publications related to the project

2017Inviscid instability of two-fluid free surface flow down an incline
Meccanica 52 955-972 (Published)
2017Optimal wavy surface to suppress vortex shedding using second-order sensitivity to shape changes
European Journal of Mechanics - B/Fluids 62 139-148 (Published)
2016The role of viscosity stratification on the global stability of two-phase jets
9th International Conference on Multiphase Flow (ICMF), Firenze, Italy (2016)   (Published)
2014Second-order perturbation of global modes and implications for spanwise-wavy actuation
Journal of Fluid Mechanics 755  (Published)
2013Linear stability of miscible two-fluid flow down an incline
Physics of Fluids 25  (Published)

Internal Reports related to the project

YearTitleDocument Type