Heat and fluid flow in entrance region of a channel with staggered baffles

摘要

Laminar fluid flow and heat transfer in the entrance region of a two dimensional horizontal channel with isothermal walls and with staggered baffles is investigated numerically. The computations are based on the finite volume method, and the SIMPLER algorithm has been implemented. Data for heat and fluid flow as well as pressure drop are presented for Reynolds numbers ranging from 50 to 500 and baffle heights between 0 and 0.75. It was observed that increasing the two parameters (blockage ratio and Reynolds number) will increase the Nusselt number, as expected. The results are reported for the thermal entrance region with 16 baffles. This relatively large number of baffles allowed us to think of working media other than air and water (to them most attention has been paid up to now) so that the Prandtl number may vary from 0.35 to 10. While most of the work available in the literature showed the effects of Reynolds number on the hydro-dynamic development of flow, it was concluded that not only the Reynolds number but also the Prandtl number affects the precise location of the periodically fully developed region similar to the case of the smooth channel. It is not surprising when one observes that most of the previous works are concentrated on low Prandtl number cases, say those of water and air while this paper considers different working media like oils.