Natural, forced and mixed convection in fibrous insulation

A numerical solution of flow and temperature distribution in fibrous insulation has been obtained. Rectangular and cylindrical geometries have been modeled. Boundary conditions included permeable hot wall and convective heat transfer at the walls. Good agreement has been obtained with published experimental and numerical values on rectangular cavities. The computed velocity and temperature profiles gave a better understanding of flow and heat transfer phenomena in fibrous insulation. Local cold wall and average Nusselt numbers presented, provide useful information in the design of the fibrous insulation for concrete reactor vessel and primary coolant piping of the gas cooled nuclear power plants. Average Nusselt number has been correlated with Rayleigh number when only natural convection is present, and with Rayleigh and Reynolds numbers when a combination of natural and forced convection is present