Thermal Effects in Incompressible Flow
As mentioned in Chapter 2, the thermal problem is decoupled from the flow problem if the fluid is incompressible and has constant properties, particularly viscosity. Therefore, thermal problems under those circumstances concentrate on solving the energy equation, an equation where the only unknown is temperature (with velocity field and pressure field already known). Most of the examples of the previous chapters can now be reconsidered in view of thermal calculations. However, when fluid properties arc not constant (that is. the case of numerous liquids, particularly viscous ones like oils), then the flow field is no longer decoupled from the temperature field. One even sometimes uses the term thermohydrodynamic in order to stress this peculiarity.
KeywordsHeat Flux Velocity Profile Nusselt Number Thermal Effect Rayleigh Number
Unable to display preview. Download preview PDF.