Heat Transfer to Power-Law Fluids from a Heated Square Cylinder

Momentum and heat transfer from a square cylinder in power-law fluids

“…Thus, the reliability of the results is contingent upon the validity of this assumption. Secondly, the scheme employed by Dhiman et al [12,13,16] failed to converge for the values of power-law index, n 6 0.6 thereby compromising the accuracy of their results for n = 0.5 which were obtained only by using a coarse grid and/or by relaxing the convergence criterion. This is also consistent with Nomenclature B…”

“…Lastly, it is well known that owing to the relatively slow decay of velocity field at low Reynolds numbers, much longer domain is needed than that at higher Reynolds numbers. Yet Dhiman et al [12,13,16] and others [10,11] employed the same upstream domain at Re = 1 and Re = 40 which is difficult to justify. Thus, while the results reported by Dhiman et al [12,13,16] are more accurate than that reported previously [10,11], but the accuracy of their results deteriorates rapidly with the decreasing value of power-law index due to the increasing difficulty in achieving the same level of convergence as that used for higher values of power-law index.…”

“…This is so in part due to the diminishing relevance of viscous forces with the increasing Reynolds number. Subsequently, Dhiman et al [12,13,16] employed a finite volume method on a staggered grid with very fine grids to study momentum and heat transport from a square cylinder to confined and unconfined flow streams of power-law fluids in the steady flow regime. Undoubtedly, not only these results on drag and Nusselt number are believed to be more accurate, but these also encompass wider ranges of Prandtl number than that reported earlier [10,11].…”

Effect of temperature-dependent viscosity on forced convection heat transfer from a cylinder in crossflow of power-law fluids

“…Furthermore, all heat transfer studies have implicit in them the assumption of constant thermo-physical properties thereby severely limiting their applicability to the situations wherein the temperature difference is small. This observation is also applicable for cylinders of square and elliptical cross sections in the two-dimensional steady flow regime [11,[37][38][39], except for the very recent work on momentum and heat transfer characteristics in the laminar vortex shedding regime for a square cylinder submerged in power-law fluids [40,41]. In summary, it is thus fair to say that, to the best of our knowledge, there has been no prior numerical or experimental study to ascertain the influence of temperature-dependent viscosity in the pure forced convection heat transfer over a circular cylinder submerged in power-law fluids.…”

Effect of power-law fluid behavior on momentum and heat transfer characteristics of an inclined square cylinder in steady flow regime

“…Consequently, reliable results are now available on drag, lift, Strouhal number and Nusselt number characteristics for a circular cylinder in power-law fluids [39][40][41][42][43][44][45][46][47] which span the laminar vortex shedding regime, albeit the limiting value of the Reynolds number denoting cessation of the laminar vortex shedding regime is not yet known [48]. Similarly, reliable results for a square cylinder (a = 0) are also available over the similar ranges of conditions [49][50][51][52][53][54][55][56][57]. Somewhat less extensive results are available for elliptic and rectangular cylinders [12,13,[58][59][60] and these are limited to the so-called steady flow regime.…”