What Does Nusselt Number Represent?
In Fluid Dynamics, the Nusselt Number (Nu) Is the Ratio of Convective to Conductive Heat Transfer at a Boundary in a Fluid. Convection Includes Both Advection...
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Keeping this in view, what does Prandtl number represent?
Prandtl number is a non-dimensional number which gives the ratio of momentum diffusivity to thermal diffusivity. Significance - Tells us how fast the thermal diffusion takes place in comparison to momentum diffusion. Tells us the relative thickness of thermal boundary layer to momentum boundary layer.
Furthermore, what is the significance of Grashof number? The significance of the Grashof number is that it represents the ratio between the buoyancy force due to spatial variation in fluid density (caused by temperature differences) to the restraining force due to the viscosisty of the fluid.
In this manner, can Nusselt number be less than 1?
It is clear from earlier statement that the Nusselt number can never be less than 1 because the convective flux can be zero but the molecular flux term will be similar in the numerator and the denominator. Therefore, the minimum value of Nusselt number is 1 when the convective flux is zero.
Does Prandtl number change with pressure?
, cp and k are known to change with temperature so the Prandtl number will change with temperature. The values of ?, cp and k are only very weak functions of pressure so the Prandtl number can be assumed to be independent of pressure.
