Crystallization on a cooled wall with forced convection in the melt

✍ Scribed by F.C.H. Jongenelen; P.M. Heertjes

• Publisher: Elsevier Science
• Year: 1978
• Tongue: English
• Weight: 747 KB
• Volume: 33
• Category: Article
• ISSN: 0009-2509
• DOI: 10.1016/0009-2509(78)85068-4

✦ Synopsis

The local heat transfer m a hqmd, which flows m a lammar stream through a duct, towards a crystal layer, formed from that hqmd, has been studled This sltuatlon resembles the classical Graetz problem, however, the occurrence of a crystal layer on the wall of the duct results m a substantial difference m heat transfer The relevant equations for momentum and heat transfer m the duct have been solved by numerical mtegratlon The solutlons have been tested agamst experlmental data Two cases have been consldered, I e the stationary state (no growth or meltmg by the crystal layer) and the non-stationary state (growmg or melting crystal layer) In the stationary state It has been found that near the leadmg edge of the crystal layer the local Nusselt number decreases more rapldty than m the sltuatlon wlthout crystal layer Further downstream the local Nusselt number approaches an asymptotic hmlt which depends on the crystal layer thickness The theoretIca solution given agrees satw factorlly with the experlmental results In the non-stationary state the local Nusselt number with growth or meftmg (Nu) has been compared with the local Nusselt number (Nuo) m the stationary state The experlmental Nu/iVuO-ratlo expresses a more pronounced mfluence of the growth rate than the theoretlcal solution For melting a broad agreement between theory and experiments has been found