Title:
Miniaturized pulse tube refrigerators

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dc.contributor.advisor Ghiaasiaan, S. Mostafa
dc.contributor.author Conrad, Theodore Judson en_US
dc.contributor.committeeMember Carl S. Kirkconnell
dc.contributor.committeeMember Desai, Prateen V.
dc.contributor.committeeMember Jeter, Sheldon M.
dc.contributor.committeeMember Timothy C. Lieuwen
dc.contributor.department Mechanical Engineering en_US
dc.date.accessioned 2011-09-22T17:48:13Z
dc.date.available 2011-09-22T17:48:13Z
dc.date.issued 2011-05-23 en_US
dc.description.abstract Pulse tube refrigerators (PTR) are robust, rugged cryocoolers that do not have a moving component at their cold ends. They are often employed for cryogenic cooling of high performance electronics in space applications where reliability is paramount. Miniaturizing these refrigerators has been a subject of intense research interest because of the benefits of minimal size and weight for airborne operation and because miniature coolers would be an enabling technology for other applications. Despite much effort, the extent of possible PTR miniaturization is still uncertain. To partially remedy this, an investigation of the miniaturization of pulse tube refrigerators has been undertaken using several numerical modeling techniques. In support of these models, experiments were performed to determine directional hydrodynamic parameters characteristic of stacked screens of #635 stainless steel and #325 phosphor bronze wire mesh, two fine-mesh porous materials suitable for use in the regenerator and heat exchanger components of miniature PTRs. Complete system level and pulse tube component level CFD models incorporating these parameters were then employed to quantitatively estimate the effects of several phenomena expected to impact the performance of miniature PTRs. These included the presence of preferential flow paths in an annular region near the regenerator wall and increased viscous and thermal boundary layer thicknesses relative to the pulse tube diameter. The effects of tapering or chamfering the junctions between components of dissimilar diameters were also investigated. The results of these models were subsequently applied to produce successively smaller micro-scale PTR models having total volumes as small as 0.141 cc for which sufficient net cooling was predicted to make operation at cryogenic temperatures feasible. The results of this investigation provide design criteria for miniaturized PTRs and establish the feasibility of their operation at frequencies up to 1000 Hz with dimensions roughly an order of magnitude smaller than those that have recently been demonstrated, provided that challenges related to their regenerator fillers and compressors can be addressed. en_US
dc.description.degree Ph.D. en_US
dc.identifier.uri http://hdl.handle.net/1853/41108
dc.publisher Georgia Institute of Technology en_US
dc.subject Cryogenic refrigeration en_US
dc.subject Cryocoolers en_US
dc.subject Miniaturization en_US
dc.subject Pulse tube en_US
dc.subject CFD en_US
dc.subject.lcsh Miniature electronic equipment
dc.subject.lcsh Refrigeration and refrigerating machinery
dc.title Miniaturized pulse tube refrigerators en_US
dc.type Text
dc.type.genre Dissertation
dspace.entity.type Publication
local.contributor.advisor Ghiaasiaan, S. Mostafa
local.contributor.corporatename George W. Woodruff School of Mechanical Engineering
local.contributor.corporatename College of Engineering
relation.isAdvisorOfPublication b1bd027d-ac1a-4f96-ad2f-394e7238320e
relation.isOrgUnitOfPublication c01ff908-c25f-439b-bf10-a074ed886bb7
relation.isOrgUnitOfPublication 7c022d60-21d5-497c-b552-95e489a06569
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