N2 - The paper presents two analytical solutions namely for Fanning friction
factor and for Nusselt number of fully developed laminar fluid flow in
straight mini channels with rectangular cross-section. This type of
channels is common in mini- and microchannel heat exchangers. Analytical
formulae, both for velocity and temperature profiles, were obtained in the
explicit form of two terms. The first term is an asymptotic solution of
laminar flow between parallel plates. The second one is a rapidly
convergent series. This series becomes zero as the cross-section aspect
ratio goes to infinity. This clear mathematical form is also inherited by
the formulae for friction factor and Nusselt number. As the boundary
conditions for velocity and temperature profiles no-slip and peripherally
constant temperature with axially constant heat flux were assumed (H1
type). The velocity profile is assumed to be independent of the
temperature profile. The assumption of constant temperature at the
channel’s perimeter is related to the asymptotic case of channel’s wall
thermal resistance: infinite in the axial direction and zero in the
peripheral one. It represents typical conditions in a minichannel heat
exchanger made of metal.
JO - Archives of Thermodynamics
L1 - http://so.czasopisma.pan.pl/Content/94670/PDF/02_paper.pdf
L2 - http://so.czasopisma.pan.pl/Content/94670
IS - No 4 December
EP - 42
KW - analytical solution
KW - heat transfer
KW - rectangular channel
KW - laminar flow fully developed
ER -
A1 - Mikielewicz, Jarosław
A1 - Rybiński, Witold
PB - The Committee on Thermodynamics and Combustion of the Polish Academy of Sciences
JF - Archives of Thermodynamics
SP - 29
T1 - Analytical solutions of heat transfer for laminar flow in rectangular channels
UR - http://so.czasopisma.pan.pl/dlibra/docmetadata?id=94670
DOI - 10.2478/aoter-2014-0031