EFFECTS OF ASYMMETRIC TEMPERATURE PROFILES ON THERMAL CONVECTION DURING PHYSICAL VAPOR TRANSPORT OF Hg2Cl2
Titel:
EFFECTS OF ASYMMETRIC TEMPERATURE PROFILES ON THERMAL CONVECTION DURING PHYSICAL VAPOR TRANSPORT OF Hg2Cl2
Auteur:
Kim, G. T. Duval, W. M. B. Glicksman, M. E.
Verschenen in:
Chemical engineering communications
Paginering:
Jaargang 162 (1997) nr. 1 pagina's 45-61
Jaar:
1997-10-01
Inhoud:
Asymmetric horizontal thermal profiles can change the flow field structure in the physical vapor transport (PVT)of Hg2Cl2. It is found that for the ratios of horizontal to vertical thermal Rayleigh numbers RaH/Ra ≥ 1·5, the convetive flow structure changes from multicellular to unicellular for the base parametric state of Ra = 2·79 × 104, Pr = 0·91, Le=l·01. Pe = 4·60, Ar= 0·2 and Cr = 1·01. The unicellular flow structure obtained by increasing ∇*H(RaH) is not likely to support the conjecture of the presence of unicellular convective mode in the laser Doppler velocimetry (LDV) experiments for PVT process of Hg2Cl2 (Kim el al., 1996). When the six parameters of Ra, Pr, Le, Pe, Ar and Cr are fixed, the dimensional maximum magnitude of the velocity vector |U|max is proportional to √∇T*H.