Mixed Convection Along Vertical Cylinders and Needles With Uniform Surface Heat Flux

Abstract

Mixed convection along vertical cylinders and needles with uniform surface heat flux is investigated for the entire mixed convection regime. A single modified buoyancy parameter χ and a single curvature parameter Λ are employed in the analysis such that a smooth transition from pure forced convection (χ = 1) to pure free convection (χ = 0) can be accomplished. For large values of the curvature parameter and/or Prandtl number, the governing transformed equations become stiff. Thus, a numerically stable finite-difference method is employed in the numerical solution in conjunction with the cubic spline interpolation scheme to overcome the difficulties that arise from the stiffness of the equations. Local Nusselt numbers are presented for 0.1 ≤ Pr ≤ 100 that cover 0 ≤ χ ≤ 1 (∞ ≥ Ωχ ≥ 0) and 0 ≤ Λ ≤ 50. For needles (Λ ≥ 5), the local Nusselt numbers Nuχ/(Reχ1/2 + Grχ*1/5) are found to be nearly independent of the buoyancy parameter χ. Correlation equations for the local Nusselt numbers are also presented.

Effect of double stratification on mixed convection boundary layer flow of a nanofluid past a vertical plate in a porous medium

“…It is noticed from Fig. 2 that the non-dimensional temperature of the fluid decreases with the increase of the thermal calculated by the present method and that of Lee et al (1987) with the variation of Prandtl number Pr stratification parameter. When the thermal stratification effect is taken into consideration, the temperature gradient between the plate and the ambient fluid will decrease.…”

“…After some trials, we imposed a maximal value of g at 1 of 10 and a grid size of Dg as 0.01. In order to assess the accuracy of our method, we have compared our results with those of Lee et al (1987) in the absence of 1 ; 2 ; n; N r ; N b ; N t ; L d and N d with the variation of Prandtl number Pr. The comparison in the above case is found to be in good agreement, as shown in Table. (2)…”

Free convective heat and mass transfer in a doubly stratified non-Darcy micropolar fluid

“…(1)-(5) reduce to the corresponding equations for a viscous fluid. Hence, the case of the mixed convection heat transfer in an unstratified Newtonian fluid flow along a cylinder of Lee et al [32] can be obtained by taking N=0, B=0, ε =1, Da→∞, ε 1 =0 and ε 2 =0, who investigated the mixed convection heat transfer in an unstratified Newtonian fluid flow along a cylinder.…”

Mathematical modeling of boundary layer flow over a moving thin needle with variable heat flux

“…We mention here Chen and Smith [4], Narain and Uberoi [5,6], Chen [7], Lee et al [8] and Ahmad et al [9] have studied various aspects of this problem. Wang [10] has studied the problem of mixed convection boundary layer flow on a vertical adiabatic thin needle with a concentrated heat source at the tip of the needle.…”