Afluid is flowing through a circulat tube at 0.4 kg/s. tube inner surface is smooth with a diameter 0.014 m. fluid density is 990 kg/m^3, specific heat is 3,845 j/(kg-k), viscosity is 0.00079 ns/m^2, thermal conductivity is 0.74, and prandtl number is 8.6. a uniform heat flux of 71,297 w/m^2 is supplied to the flow from the surface. if the flow is fully developed, what is the convection coefficient in w/(m^2-k)

The convection coefficient is

Solution:

Mass flow rate,

Inner diameter of the tube, d = 0.014 m

Fluid density,

Specific Heat, C = 3845 J/K

Thermal Conductivity, K = 0.74

Prandtl Number,

Heat flux,

Viscosity,

Now,

To calculate the convection heat coefficient, h:

Determine the cross sectional area of the circular tube:

Determine the velocity of the fluid inside the tube by mass flow rate:

v = 2.624 m/s

Determine the Reynold's Number, :

Thus it is clear that > 10,000 hence flow is turbulent.

Now,

Determine the Nusselt Number:

Also,

where

h = convection coefficient

Now,

the one with the highest speed