Justyna Czerwińska, PhD


Recent publications
1.Czerwińska J., Jebauer S., Secondary slip structures in heated micro-geometries, INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, ISSN: 0017-9310, Vol.54, pp.1578-1586, 2011
2.Abate A.R., Poitzsch A., Hwang Y., Lee J., Czerwińska J., Weitz D.A., Impact of inlet channel geometry on microfluidic drop formation, PHYSICAL REVIEW E, ISSN: 1539-3755, DOI: 10.1103/PhysRevE.80.026310, Vol.80, pp.26310-5, 2009
Abstract:

We study the impact of inlet channel geometry on microfluidic drop formation. We show that drop makers with T-junction style inlets form monodisperse emulsions at low and moderate capillary numbers and those with Flow-Focus style inlets do so at moderate and high capillary numbers. At low and moderate capillary number, drop formation is dominated by interfacial forces and mediated by the confinement of the microchannels; drop size as a function of flow-rate ratio follows a simple functional form based on a blocking-squeezing mechanism. We summarize the stability of the drop makers with different inlet channel geometry in the form of a phase diagram as a function of capillary number and flow-rate ratio.

Affiliations:
Abate A.R.-University of California (US)
Poitzsch A.-Pinkerton Academy (US)
Hwang Y.-St. Paul’s School (US)
Lee J.-Lexington High School (US)
Czerwińska J.-IPPT PAN
Weitz D.A.-Harvard University (US)
3.Lewandowski T., Jebauer S., Czerwińska J., Doerffer P., Entrance effects in microchannel gas flow, Journal of Thermal Science, ISSN: 1003-2169, DOI: 10.1007/s11630-009-0345-5, Vol.18, No.4, pp.345-352, 2009
Abstract:

Motivation of this work has its origin in the boundary layer control for aeronautics and turbomachinery. For that purpose boundary layer can be modified by perforated plates with holes of specific sizes. The questions which rise in such configuration are related to the existence of optimal size of the holes and the influence of microscale phenomena on the global flow patterns. This paper concentrates on the issue of the entrance effects on the microchannel flow. It is shown that mass flow rate is only insignificantly influenced by slip effects. Global parameters such as pressure difference and geometrical shape in more pronounced way alter flow behavior. In this paper we concentrate on the numerical investigation of the microchannel flow for Kn < 0.01 and Re < 500. The channel length is finite. Hence, entrance and outlet effects on microchannel flow can be studied.

Keywords:

perforated plates, microchannels, gas flow simulations

Affiliations:
Lewandowski T.-other affiliation
Jebauer S.-IPPT PAN
Czerwińska J.-IPPT PAN
Doerffer P.-Institute of Fluid Flow Machinery, Polish Academy of Sciences (PL)
4.Czerwińska J., Self-diffusion effects in micro scale liquids. Numerical study by a dissipative particle dynamics method, BULLETIN OF THE POLISH ACADEMY OF SCIENCES: TECHNICAL SCIENCES, ISSN: 0239-7528, Vol.55, pp.159-172, 2007

List of recent monographs
1.
70
Jebauer S., Czerwińska J., Implementation of velocity slip and temperature jump boundary conditions for microfluidic devices, IPPT Reports on Fundamental Technological Research, 5, pp.1-56, 2007