Flow in a rapidly rotating cone-shaped PCR-tube
2011 (English)In: International journal of numerical methods for heat & fluid flow, ISSN 0961-5539, Vol. 21, no 6, 717-735 p.Article in journal (Refereed) Published
Purpose - A precise and rapid temperature cycling of a small volume of fluid is vital for an effective DNA replication process using the polymerase chain reaction (PCR). The purpose of this paper is to study the velocity and temperature fields inside a rotating PCR-tube during cooling of the enclosed liquid. Design/methodology/approach - The velocity and temperature fields inside a rotating PCR-tube during cooling of the enclosed liquid are studied. By using computational fluid dynamics, the time development of the flow can be investigated in detail. Owing to the rotation, the flow exhibits features which could never arise in a non-rotating system. Findings - An intricate azimuthal boundary layer flow is presented and explained. The inherent problem of stratification of the temperature is discussed, and different methods towards a remedy are presented. By analyzing the governing equations, some properties of the flow observed in the simulations are explained. It is shown that increasing the rate of rotation does not improve temperature homogenization. Research limitations/implications - The simulations were performed for a limited number of temperature boundary conditions, as well as a specific simulation geometry. Practical implications - The analytical and simulation results offer fundamental insight into the physics behind increased DNA duplication. Further simulations offer possible design improvements. Originality/value - While many studies have probed the effects of buoyancy in rotating cylinders and the development of boundary layers in stratified flows in conical containers rotating around their axis of symmetry, little work has been specifically focused on the case where the axis of rotation is normal to the direction of the stratification, which is the case in the present study.
Place, publisher, year, edition, pages
2011. Vol. 21, no 6, 717-735 p.
Rotation, Computational fluid mechanics, Coriolis effects, Biomedical flow
Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:kth:diva-5624DOI: 10.1108/09615531111148473ISI: 000296602900003ScopusID: 2-s2.0-79960782001OAI: oai:DiVA.org:kth-5624DiVA: diva2:10052
FunderSwedish e‐Science Research Center
QC 201009132006-04-272006-04-272012-05-24Bibliographically approved