| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 652410 | Experimental Thermal and Fluid Science | 2007 | 7 Pages |
An experimental study of the laminar free convective average heat transfer in air from isothermal vertical slender cylinder having circular cross-section was performed using a transient technique. These results obtained for Prandtl number Pr = 0.71 in the range of Rayleigh number 1.5 × 108 < RaH < 1.1 × 109 and dimensionless height of 0 < H/D < 60 are correlated with the equationNuH=ARaHnwhere A = 0.519 + 0.03454(H/D) + 0.0008772(H/D)2 + 8.855 × 10−6(H/D)3 and n = 0.25–0.00253 (H/D) + 1.152 × 10−5 (H/D)2 agree well with the known numerical data which are approximated with the equation NuH/NuH−FP = f(GrH, H/D) valid in laminar boundary layer region (GrH-crit ⩽ 4 × 109) for fluids of Prandtl number within 0.01 < Pr < 100 and for the transverse curvature parameter ξ=32GrH0.25HD<5. Besides the slenderness criterion determining situation when the vertical isothermal cylinder of circular cross-section cannot be treated as a flat plate is presented in the form GrH0.25DH⩽f(Pr).
