Measurement of heat transfer coefficients by nuclear magnetic resonance

✍ Scribed by David H. Gultekin; John C. Gore

• Publisher: Elsevier Science
• Year: 2008
• Tongue: English
• Weight: 429 KB
• Volume: 26
• Category: Article
• ISSN: 0730-725X
• DOI: 10.1016/j.mri.2008.04.006

✦ Synopsis

We demonstrate an experimental method for the measurement of heat transfer coefficient for a fluid system by magnetic resonance imaging. In this method, the temporal variation of thermally induced nuclear shielding is monitored and the average heat transfer coefficient is measured as a function of fluid velocity. We examine the cases of natural convection and forced convection at fluid velocity up to 0.8 m s -1 . These cases correspond to low dimensionless Biot (Bi) number where the heat transfer is limited by thermal convection. We demonstrate the NMR method for two simple geometries, a cylinder and a sphere, to experimentally determine the heat transfer coefficient (h) in two NMR imaging and spectroscopy systems through measuring three NMR parameters, the chemical shift, magnetization and spin self diffusion coefficient.