Transient natural convective heat transfer and fluid flow in an undulated cavity: Effects of localized heat sources: Fid-Bau Portal

Transient natural convective heat transfer and fluid flow in an undulated cavity: Effects of localized heat sources

Choudhary, Pankaj / Ray, Rajendra K.

The purpose of this research work is to investigate two‐dimensional transient natural convective heat transfer and fluid flows in an undulated cavity by placing solid objects with isolated heated surfaces on the bottom wall. We discretize the coupled nonlinear transport equations using a higher‐order compact finite‐difference scheme. First, we test our scheme using existing experimental and numerical data. Then, we analyze the transient and steady‐state natural convective flow phenomena for distributed heat sources on corrugations on the lower wall for a range of the Rayleigh number $(R a = 1 0^{3} - 1 0^{6})$ and Prandtl number $(P r = 0.71)$ . These simulated outcomes are presented in the form of central‐line velocity $(u, v)$ , local $(N u_{h}^{*}, N u_{v}^{*})$ and averaged $(\bar{N u_{h}^{*}}, \bar{N u_{v}^{*}})$ Nusselt numbers, streamlines $(ψ)$ , dispersion of isotherms $(T)$ , and so forth. It is found that the transient fluid flow behavior is more magnificent than the steady‐state solutions and shows the dominant behavior of the prominent primary cells over secondary cells, where it influences the heat transfer rates inside the entire enclosure. In steady states, at high Rayleigh numbers; convection dominates, formation of thermal boundary layers, compression of isotherms, and stratification of isotherms are significantly observed. Our results show many interesting flow phenomena that have not been analyzed previously.