Forced convection heat transfer to supercritical helium

✍ Scribed by P.J. Giarratano; V.D. Arp; R.V. Smith

• Publisher: Elsevier Science
• Year: 1971
• Tongue: English
• Weight: 879 KB
• Volume: 11
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/0011-2275(71)90038-5

✦ Synopsis

Heat transfer coefficients have been measured for super° critical helium, circulated around a closed flow loop by a miniature centrifugal pump. Reynolds numbers in the 0"208cm i d by lOcm long stainless steel test section ranged from 1 x 10 4 to 3"8x 10 5 with pressures 3 to 20 atm (0"3 to 2 MN m -2) and fluid temperatures 4 "4 to 30 K. Wall-to-bulk temperature ratios varied from approximately 1"03 to 3"0. Results indicate an enhancement in heat transfer as the bulk temperature of the fluid approaches the i i transposed critical temperature. This improvement is qualitatively predicted by classical correlations due to the increase of thermal conductivity and specific heat in this region. Over the range of variables included in the measurements it was found that a modification of the Dittus-Boelter heat transfer correlation can be used to predict the heat transfer coefficient satisfactorily for most engineering calculations.