Laminar Mixed Convection in the Entrance Region of a Horizontal Annulus

Abstract

A numerical study is presented for the combined forced and free convection in the entrance region of a horiwnlnl annulus with mdius m ' o of 2. Results are presented for developing velocity pmfiles, temperature Jield, local pressure gmdient, and the circumferentially avemged Nusself number. These resulfs reveal thal the buoy<mcy-induced secondary flow has considemble influence on the fluidflow and heat transfer chamctenstics of the developing flow.

Natural convection of nanofluids in an enclosure between a circular and a sinusoidal cylinder in the presence of magnetic field

“…This investigation revealed that the Nusselt number is considerably greater for developing flow than the corresponding values for fully developed flow over a significant portion of the annulus. Karki and Patankar [2] presented a numerical study for the combined convection in the entrance region of a horizontal annulus with a fixed radius ratio of 2. The results were presented for developing velocity and temperature fields, local pressure gradient, and the circumferentially averaged Nusselt number.…”

Natural convection between a circular enclosure and an elliptic cylinder using Control Volume based Finite Element Method

“…He observed that flow and thermal behavior depended on heat fluxes imposed on the inner cylinder within the isothermal enclosure. Karki and Patankar [7] presented a numerical study for the combined convection in the entrance region of a horizontal annulus with a fixed radius ratio of 2. The results were presented for developing velocity and temperature fields, local pressure gradient, and the circumferentially averaged Nusselt number.…”

Hydrodynamic Analysis of Laminar Mixed Convective Flow of Ag-TiO2-Water Hybrid Nanofluid in a Horizontal Annulus

“…The condensers for seawater distillation, underground electric transmission cable using pressurized gas, cooling of turbine rotors, the chemical vapor deposition processes for the fabrication of semiconductor devices, the thermal storage systems, the food processes, and the thermal insulation are additional examples where the results of buoyancy-influenced convection heat transfer in annulus pipe are useful. Investigations [7][8][9][10][11][12] on mixed convection in horizontal annuli revealed that heat transfer augmentation for simultaneously developing flow is higher than that for fully developed flow [13][14][15][16][17][18]. It has been observed that further improvement in heat transfer performance can be achieved by using nanofluid [19,20] in place of conventional cooling fluids such as water, oil, and air.…”