What is the meaning of Nusselt number?
The Nusselt number is defined as the ratio of convection heat transfer to fluid conduction heat transfer under the same conditions.
What do you mean by thermal boundary layer?
the layer of a liquid or gaseous heat-transfer agent between the free stream and a heat-exchange surface. In this layer the temperature of the heat-transfer agent changes from that of the wall to that of the free stream (seeBOUNDARY LAYER).
What is Nusselt number Quora?
Nusselt number is ratio of convective heat transfer to conductive heat transfer. There can be heat transfer by Conduction and Convection in fluids. Nu= (h*Lc)/k.
How do you find the average Nusselt number in fluent?
In Fluent the surface nusselt number is calculated based upon the formula ((h_eff*L_ref) / k) where h_eff is heat transfer coefficient and L_ref is reference length which you define in refernce values panel and k is thermal conductivity.
What is meant by critical Reynolds number?
1 Critical Reynolds Number. A critical Reynolds number is determined as a limit where the laminar flow changes to turbulent flow. If the calculated NRe is greater than the critical Reynolds number NRec, the flow regime is turbulent; otherwise the flow regime is laminar.
What is meant by fin efficiency?
Fin efficiency is defined as the ratio of actual heat flow of the fin to that which would be obtained with a fin of constant temperature uniformly equal to the base surface temperature, that is, one with infinite thermal conductivity.
What does Grashof number represent?
The Grashof number (Gr) is a dimensionless number in fluid dynamics and heat transfer which approximates the ratio of the buoyancy to viscous force acting on a fluid. It frequently arises in the study of situations involving natural convection and is analogous to the Reynolds number.
What is the difference between forced and natural convection?
In natural convection, any fluid motion is caused by natural means such as the buoyancy effect, i.e. the rise of warmer fluid and fall the cooler fluid. Whereas in forced convection, the fluid is forced to flow over a surface or in a tube by external means such as a pump or fan.
