Numerical analysis for oscillatory natural convection for low Prandtl number fluid heated from below

Journal Article · Wed Mar 01 04:00:00 EST 1995 · Numerical Heat Transfer. Part A, Applications

DOI:https://doi.org/10.1080/10407789508913702· OSTI ID:63003

Ozoe, Hiroyuki; Hara, Teiji ^[1]

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1. Kyushu Univ., Kasuga (Japan). Inst. of Advanced Material Study

Finite difference numerical computations were carried out for the horizontal fluid layer heated from below and cooled front above for Prandtl numbers front 0.1 to 0.001 and for Raleigh numbers up to 16,000 (for Pr = 0.01). The aspect ratio (width / height) of a computational regime was generally 4 to allow for the appearance of multiple roll cells. The initiation of oscillatory convection and multiplication in the number of roll cells was detected and found to be affected by the Raleigh and Prandtl numbers with grid sizes up to 201 {times} 51. However, the oscillatory characteristics were found to be still dependent on the computational grid size. The critical Raleigh number for the initiation of oscillation was found by extrapolating to zero grid size. The oscillation appears to occur even just after the initiation of convection at 1708 for Prandtl numbers levy than 0.01. Oscillatory natural convection of low Prandtl number fluid has been known and considered to be responsible for the striae in crystal rods.

• Sponsoring Organization: USDOE
• OSTI ID: 63003
• Journal Information: Numerical Heat Transfer. Part A, Applications, Journal Name: Numerical Heat Transfer. Part A, Applications Journal Issue: 3 Vol. 27; ISSN NHAAES; ISSN 1040-7782
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL GROWTH METHODS
CRYSTALS
LIQUIDS
NATURAL CONVECTION
STRIATIONS