Turbulent mixed convection in a vertical cusped duct
Conference
Dong, ZF, Ebadian, MA. (1993). Turbulent mixed convection in a vertical cusped duct
. American Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD, 247 53-60.
Dong, ZF, Ebadian, MA. (1993). Turbulent mixed convection in a vertical cusped duct
. American Society of Mechanical Engineers, Heat Transfer Division, (Publication) HTD, 247 53-60.
In the event of a loss of coolant accident (LOCA) in a pressurized water reactor, swelling of the fuel rod cladding will lead to reduction of the subchannel flow area and worsening of the core heat transfer in the region of the blockage. The four-cusped duct is an ideal geometry for the simulation of such a channel blockage. Understanding the characteristics of flow and heat transfer in the cusped duct is essential for better design of the emergency core cooling system (ECCS). Thus, in this paper, turbulent mixed convection in a cusped duct has been investigated in the region of both hydrodynamically and thermally fully developed flow. Negligible secondary flow in the cross section of the duct has been assumed in this analysis. The thermal boundary condition imposed on the cusped duct is the uniform axially heat flux and a uniform temperature peripherally. The results of the study indicate that natural convection has an effect on turbulent forced convection only in low Reynolds number flow. The influence of natural convection is diminished as the Reynolds number increases. Furthermore, it is shown that natural convection has more effect on turbulent flow than on heat transfer. The flow and heat transfer in the corner region of the cusped duct still remain weak, although the flow and heat transfer in other regions are enhanced by turbulence and natural convection. The turbulent flows in the rectangular duct and the cusped duct are analyzed by the present method, and excellent agreement has been achieved between the predictions and the data available from the literature surveyed.
