Entry point to
the full-text publications of NASA's "Thermal Energy Conversion at
NASA Glenn Research Center"
FY 2012 publications : nothing of interest for fluid flow/heat transfer
FY 2011 publications : nothing of interest for fluid flow/heat transfer
FY 2010 publications : nothing of interest for fluid flow/heat transfer
FY 2009 publications : nothing of interest for fluid flow/heat transfer
FY 2008 publications : nothing of interest for fluid flow/heat transfer
FY 2007 publications : nothing of interest for fluid flow/heat transfer
FY 2006 publications : nothing of interest for fluid flow/heat transfer
FY 2005 publications : nothing of interest for fluid flow/heat transfer
No prior publications avialable at this site.
Sage is a dedicated thermodynamic code for modeling Stirling-cycle based machines, developed by Gedeon
Associates of Athens, OH (Gedeon, 1995).
Oscillatory flow and heat transfer in a Stirling Engine Regenerator
by Yuan,Zheng Shan, PhD Thesis at Case Western Reserve Univeristy, 1993
myCopy to be studied.
Obtained via http://www.libraries.psu.edu/psul/montalto.html
 UPDATE ON THE EVALUATION OF DIFFERENT CORRELATIONS
FOR THE FLOW FRICTION FACTOR AND HEAT TRANSFER
OF STIRLING ENGINE REGENERATORS, Bernd Thomas, Deborah Pittman, 2000,
Re-evaluates the experimental data obtained at the
Oscillating-Flow Regenerator Test Rig. Experimental data from
Tong/London, Blass, Miyabe etal, Tanaka,
et.al., ILK Dresden and Kuehl plus
data presented by Gedeon and Wood. Parameters varied are
Reynolds number, Valensi number, flush ratio, wire diameter, mesh width and porosity, and gas type ( air and He ), see their Table 1. This table also includes
the equations they think are most relevant. For example for a regenerator
which uses wire screens as the matrix :
L = length of regenerator volume
d = wire diameter
rho = density of working fluid
nue = kinematic viscosity of working fluid
epsilon = porosity = 1 - Vmaterial/Vtot
unod = empty tube velocity
u = unod /epsilon
pressure drop = cF*------------- * --- * u
with friction coefficient cF = 129/Re + 2.91/Re^0.103
and Re-number : Re = ---------------
Similar equations are given for heat transfer and for metal felts.
The experiments by Gedeon and Wood (which are the main topic of
this paper) are
described as :
"The Oscillating-Flow Regenerator Test Rig was
specially designed to analyze regenerator pressure chop
and heat transfer for oscillating flow. For that purpose a
motor-driven piston-cylinder assembly was installed to
push gas back and forth through the regenerator sample.
The friction factor was calculated fiom the piston
pV-power, which was measured directly. To measure
heat transfer, the regenerator sample was inserted
between a heater and cooler in order to imposes an axial
temperature gradient along the regenerator."
Reynolds numbers are always below 3400 = laminar flow limit ? Is that the reason while the equaions don't show any dependency on Valensi number ?
As these equations give only averages over a complete oscillation they are
useful in estimating energy losses and heat transfer performance once
an ideal adiabatic analysis has been conducted.
Oscillatory Flow and Thermal Field Measurements at the Interface
between a Heat Exchanger and a Regenerator of a Stirling Engine, Niu &
Simon & lbrahim & Gedeon, 2002 37th Intersociety Energy Conversion Engineering Conference (IECEC)
This is an interim report representing the experimental facility
together with some preliminary instantaneous velocity and temperature
data. Reynolds number of 20700 (the length
scale is the cooler tube diameter and the velocity scale is the cycle
maximum bulk mean velocity in the cooler tubes).Valensi number of 14.3
(VA=ω*d^2/(4*nue) ; ω=2*πF ; d = cooler tube inner diameter
Because of its interim nature data valuable for the construction
of cooler/regenerator/heater are not available. Not that this research
is conducted under the
"US. Department of Energy Office of Energy
Efficiency and Renewable Energy under the
Advancement of Solar DishIConverter Technology
Nice entry into that program, worthwhile to read again to look
at some of their references.