Heat Transfer Coefficients — Internal Natural Convection
Narrow Chimney, Parallel Plates
Figure 4-35: Schematic representation of geometry and parameters for the heat transfer coefficient correlation applied to natural convection in a parallel-plate narrow chimney.
If RaL < H ⁄ L, then
(4-188)
where the plate distance, L, and the chimney height, H, are correlation inputs (equation 7.96 in Ref. 41). RaL is given by Equation 4-179 or Equation 4-180. The material data are evaluated at (T + Text) ⁄ 2.
Narrow Chimney, Circular Tube
Figure 4-36: Schematic representation of geometry and parameters for the heat transfer coefficient correlation applied to natural convection in a circular narrow chimney.
If RaD < H ⁄ D, then
where the tube diameter, D, and the chimney height, H, are correlation inputs (table 7.2 in Ref. 41 with Dh = D). RaD is given by Equation 4-179 or Equation 4-180 with L replaced by D. The material data are evaluated at (T + Text) ⁄2.