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You searched for subject:(Hydrodynamic resistance parameters). Showing records 1 – 2 of 2 total matches.

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1. Perrella, Matthew Drake. Periodic flow hydrodynamic resistance parameters for various regenerator filler materials at cryogenic temperatures.

Degree: PhD, Mechanical Engineering, 2017, Georgia Tech

The regenerator is a critical component of all Stirling and Pulse Tube cryocoolers. It generally consists of a microporous metallic or rare-earth filler material contained within a cylindrical shell. The accurate modeling of the hydrodynamic and thermal behavior of different regenerator materials is crucial to the successful design of cryogenic systems, specifically Stirling and pulse-tube cryocoolers. Previous investigations have used experimental measurements at steady and periodic flow conditions in conjunction with pore-level CFD analysis to determine the pertinent hydrodynamic parameters, namely the Darcy permeability and Forchheimer coefficients. Due to the difficulty associated with experimental measurement at cryogenic temperatures, past investigations where performed at ambient conditions. These results are assumed to be accurate for cryogenic temperatures since, for fully-developed flow, the Darcy and Forchheimer coefficients should depend only on the geometry of the porous medium. There is, however, a pressing need in the literature to determine the hydrodynamic parameters for several regenerator materials under prototypical conditions and verify the validity of the foregoing assumption. In this analysis, regenerators filled with several common materials including spherical Er50Pr50 powder,400SS mesh, and #325SS mesh were assembled and tested under periodic helium flow at cryogenic temperatures. The mass flow and pressure drop data was correlated with a porous media CFD model to determine the Darcy Permeability and Forchheimer coefficients. These results are compared to the previous investigations at ambient temperature conditions, and the relevance of room-temperature models and correlations to cryogenic temperatures is critically assessed. Advisors/Committee Members: Ghiaasiaan, Mostafa (advisor), Zhang, Zhuomin (committee member), Ranjan, Devesh (committee member), Walker, Mitchell II (committee member), Kashani, Ali (committee member).

Subjects/Keywords: Hydrodynamic resistance parameters; Stirling cryocooler; Pulse tube cryocooler; Regenerator; Cryogenics; Porous media

…determination of hydrodynamic resistance parameters… …examine the effect of cryogenic temperatures on the hydrodynamic resistance parameters of… …hydrodynamic resistance parameters. This work will investigate several common materials that are… …correlations were developed to predict these hydrodynamic resistance parameters across a wide range… …8. Investigation of anisotropic hydrodynamic resistance for #400SS mesh at 0.26 MPa and… 

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Perrella, M. D. (2017). Periodic flow hydrodynamic resistance parameters for various regenerator filler materials at cryogenic temperatures. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/59239

Chicago Manual of Style (16th Edition):

Perrella, Matthew Drake. “Periodic flow hydrodynamic resistance parameters for various regenerator filler materials at cryogenic temperatures.” 2017. Doctoral Dissertation, Georgia Tech. Accessed September 23, 2020. http://hdl.handle.net/1853/59239.

MLA Handbook (7th Edition):

Perrella, Matthew Drake. “Periodic flow hydrodynamic resistance parameters for various regenerator filler materials at cryogenic temperatures.” 2017. Web. 23 Sep 2020.

Vancouver:

Perrella MD. Periodic flow hydrodynamic resistance parameters for various regenerator filler materials at cryogenic temperatures. [Internet] [Doctoral dissertation]. Georgia Tech; 2017. [cited 2020 Sep 23]. Available from: http://hdl.handle.net/1853/59239.

Council of Science Editors:

Perrella MD. Periodic flow hydrodynamic resistance parameters for various regenerator filler materials at cryogenic temperatures. [Doctoral Dissertation]. Georgia Tech; 2017. Available from: http://hdl.handle.net/1853/59239


Georgia Tech

2. Landrum, Evan. Anisotropic parameters of mesh fillers relevant to miniature cryocoolers.

Degree: MS, Mechanical Engineering, 2009, Georgia Tech

Computational fluid dynamics (CFD) modeling is possibly the best available technique in designing and predicting the performance of Stirling and pulse tube refrigerators (PTR). One of the limitations of CFD modeling of these systems, however, is that it requires closure relations for the micro porous materials housed within their regenerators and heat exchangers. Comprehensive prediction of fluid-solid interaction through this media can be obtained only by direct pore level simulation, a process which is time consuming and impractical for system level examination. Through the application of empirical correlations including the Darcy permeability and Forchheimer's inertial coefficient, the microscopic momentum equations governing fluid behavior within the porous structure can be recast as viable macroscopic governing equations. With these constitutive relationships, CFD can be an efficient and powerful tool for system modeling and optimization. The purpose of this study is to determine the hydrodynamic parameters of two mesh fillers relevant to miniature PTRs; stacked screens of 635 mesh stainless steel and 325 mesh phosphor-bronze wire cloth. Experimental setups were designed and fabricated to measure steady and oscillatory pressures and mass flow rates of the working fluid, research-grade helium. Hydrodynamic parameters for the two mesh fillers were determined for steady-state and steady periodic flow in both the axial and radial directions for a range of flow rates, operating frequencies and charge pressures. The effect of average pressure on the steady axial flow hydrodynamic parameters of other common PTR filler materials was also investigated. The determination of sample hydrodynamic parameters and their subsequent computational and experimental methodologies utilized are explained. Advisors/Committee Members: Ghiaasiaan, S. Mostafa (Committee Chair), Desai, Prateen (Committee Member), Jeter, Sheldon (Committee Member), Kirkconnell, Carl (Committee Member).

Subjects/Keywords: Hydrodynamic parameters; CFD modeling; Steady flow parameterization; Oscillatory flow parameterization; Resistance coefficients; Porous media; Anisotropic friction factor; Darcy permeability; Forchheimer's inertial coefficient; Anisotropy; Low temperature engineering; Refrigeration and refrigerating machinery; Computational fluid dynamics; Miniature electronic equipment

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Landrum, E. (2009). Anisotropic parameters of mesh fillers relevant to miniature cryocoolers. (Masters Thesis). Georgia Tech. Retrieved from http://hdl.handle.net/1853/28159

Chicago Manual of Style (16th Edition):

Landrum, Evan. “Anisotropic parameters of mesh fillers relevant to miniature cryocoolers.” 2009. Masters Thesis, Georgia Tech. Accessed September 23, 2020. http://hdl.handle.net/1853/28159.

MLA Handbook (7th Edition):

Landrum, Evan. “Anisotropic parameters of mesh fillers relevant to miniature cryocoolers.” 2009. Web. 23 Sep 2020.

Vancouver:

Landrum E. Anisotropic parameters of mesh fillers relevant to miniature cryocoolers. [Internet] [Masters thesis]. Georgia Tech; 2009. [cited 2020 Sep 23]. Available from: http://hdl.handle.net/1853/28159.

Council of Science Editors:

Landrum E. Anisotropic parameters of mesh fillers relevant to miniature cryocoolers. [Masters Thesis]. Georgia Tech; 2009. Available from: http://hdl.handle.net/1853/28159

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