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Characterizing he ii flow through porous materials using counterflow data
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Maddocks Jr., J. R. Vansciver, Steven W. |
| Copyright Year | 1990 |
| Description | Proposed space applications, such as the cooling of infrared and x ray telescopes, have generated substantial interest in the behavior of He II flowing in porous materials. For design purposes, classical porous media correlations and room temperature data are often used to obtain order of magnitude estimates of expected pressure drops, while the attendant temperature differences are either ignored or estimated using smooth tube correlations. A more accurate alternative to this procedure is suggested by an empirical extension of the two fluid model. It is shown that four empirical parameters are necessary to describe the pressure and temperature differences induced by He II flow through a porous sample. The three parameters required to determine pressure differences are measured in counterflow and found to compare favorably with those for isothermal flow. The fourth parameter, the Gorter-Mellink constant, differs substantially from smooth tube values. It is concluded that parameter values determined from counterflow can be used to predict pressure and temperature differences in a variety of flows to an accuracy of about + or - 20 pct. |
| File Size | 400348 |
| Page Count | 8 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19920002077 |
| Archival Resource Key | ark:/13960/t9c58hh68 |
| Language | English |
| Publisher Date | 1990-12-31 |
| Access Restriction | Open |
| Subject Keyword | Fluid Mechanics And Heat Transfer Cooling Isothermal Flow Porous Materials Temperature Gradients X Ray Telescopes Pressure Gradients Infrared Telescopes Temperature Effects Counterflow Cryogenics Liquid Helium Porosity Technology Utilization Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
