Publications

Andrew Michael Rowe

2003

Paulo V Trevizoli, Theodor V Chistiaanse, Premakumara Govindappa, Iman Niknia, Reed Teyber, Jader R Barbosa, Andew Rowe

2016/3/1

Science and Technology for the Built Environment

Active magnetic regeneration (AMR) is one of the most promising alternative technologies
for the development of heat pumps and cooling systems for applications around room
temperature. In the open literature numerous works can be found in which much effort has
been put on the development of magnetocaloric materials, magnetic circuits and prototypes.
In this paper we discuss some of the main challenges encountered in the literature and how
design choices impact cooling power and work requirements from a system engineering …

R Teyber, PV Trevizoli, TV Christiaanse, P Govindappa, I Niknia, A Rowe

2016/6/6

Applied Thermal Engineering

Abstract Magnetic heat pumps and cooling systems typically use a magnetocaloric material
in an active magnetic regenerator (AMR) cycle for application near room temperature. One
method of improving AMR performance is to layer regenerators with spatially varying Curie
(or transition) temperatures. To study the impact of layering on AMR performance, four
regenerator compositions comprised of two-layers are experimentally tested with interface
temperature measurements. Each regenerator uses Gd as the layer with the highest Curie …

Paulo V Trevizoli, Jader R Barbosa, Armando Tura, Daniel Arnold, Andrew Rowe

2013/7/14

ASME 2013 Heat Transfer Summer Conference collocated with the ASME 2013 7th International Conference on Energy Sustainability and the ASME 2013 11th International Conference on Fuel Cell Science, Engineering and Technology

The active magnetic regenerator (AMR) is at the heart of the thermo-magnetic
Brayton cooling cycle. It consists of a porous matrix heat exchanger whose solid phase is a
magnetocaloric material (solid refrigerant) that undergoes a reversible magnetic phase
transition when subjected to a changing magnetic field. The cooling capacity of the cycle is
proportional to the mass of solid refrigerant, operating frequency, volumetric displacement of
the working fluid (generally an aqueous solution) and regenerator effectiveness. AMRs …

Thomas Burdyny, Danny S Arnold, Andrew Rowe

2014/8/31

Cryogenics

Abstract Temperature span, cooling power, work, and efficiency are key performance metrics
describing active magnetic regenerators used as refrigerators. Numerical methods to
calculate these parameters efficiently and accurately are needed. This paper proposes a set
of semi-analytic relationships to determine cooling power and magnetic work as a function of
temperature span, regenerator characteristics, operating conditions, and magnetic field
waveform. Appropriate effective values for magnetocaloric effect and specific heat are …

Paulo V Trevizoli, Yifeng Liu, Armando Tura, Andrew Rowe, Jader R Barbosa Jr

Proc. ExHFT-8, June

ABSTRACT Regenerators are storage-type heat exchangers with wide-range application in
thermal systems. In refrigeration, they can be used as passive storage devices, such as in
Stirling coolers, or as active magnetic regenerators in magnetocaloric refrigerators. In either
case, the performance of the cooling system is influenced by the regenerator effectiveness
and by viscous losses. A laboratory passive regenerator apparatus was developed with the
objective of measuring viscous losses and heat transfer effectiveness, using water as a …

A Rowe, A Tura, MA Richard, R Chahine, J Barclay

2003

Advances in Cryogenic Engineering; Volume 49 B

ABSTRACT Active Magnetic Regenerative (AMR) Refrigeration is currently being
investigated by the authors in the hopes of creating compact and efficient devices for the
liquefaction of cryofuels. In the past, progress has been hindered by a lack of understanding
as to how one creates an effective AMR. Measurements of the thermodynamic properties of
potential refrigerants were found to be insufficient and dynamic tests of materials undergoing
an AMR cycle were needed. To address this need, an AMR Test Apparatus was …

A Rowe

2011/1/31

International Journal of Refrigeration

The commercialization of magnetic refrigerators depends upon the ability to meet
performance targets while having acceptable equipment costs. This paper links device
design parameters and performance of magnetic refrigerators to the cost of cooling
delivered. A device configuration parameter, D, is defined that links the field volume to the
volume of magnetocaloric material. Combined with the magnet performance parameter,
efficiency, and specific exergetic cooling, the cost structure of a magnetic refrigerator is …

A Tura, J Roszmann, J Dikeos, A Rowe

2006/4/27

Advances in Cryogenic Engineering; Volume 51 A

An AMR Test Apparatus (AMRTA) used in experiments near room-temperature
required a number of modifications to allow for testing at cryogenic temperatures and with a
5 T magnetic field. The impacts of parasitic heat leaks, frictional heat generation, and eddy
current heating in the AMRTAare analyzed. A low temperature gas circulation (LTGC)
system to control the operating temperature was developed. The LTGC consists of a GM
cryocooler coupled to a compressor and helium circuit which circulates fluid through a set …

A Rowe, A Tura

2008/3/16

ADVANCES IN CRYOGENIC ENGINEERING: Transactions of the Cryogenic Engineering Conference-CEC, Vol. 53

An AMR test apparatus has been developed for testing magnetic regenerators at
temperatures ranging from room-temperature to 20 K. Near 300 K, no-load temperature
spans over 80 K have been produced using regenerators composed of two and three
different magnetocaloric materials. Modifications to the apparatus have been performed to
allow testing at cryogenic temperatures. Initial tests near 80 K using magnetic fields of 5 T
are presented using an AMR composed of Gd 5 Si 0.33 Ge 3.67. A no-load temperature …