it depends on the fluid, for example, water has higher heat transfer coefficient in comparison with oils.

for water, you can use the following equation:

h=(0.913-0.42LOG(D))*(165 +1.7T)(V^0.805)

where D is the inner diameter of the tube in inch

V is the average velocity of water in the tube in FPS

T is the average temperature of water in F

then h will be calculated in BTU/(hr-square ft- F)

it depends on the fluid, for example, water has higher heat transfer coefficient in comparison with oils.

for water, you can use the following equation:

h=(0.913-0.42LOG(D))*(165 +1.7T)(V^0.805)

where D is the inner diameter of the tube in inch

V is the average velocity of water in the tube in FPS

T is the average temperature of water in F

then h will be calculated in BTU/(hr-square ft- F)

Thank you.

it depends on the various parameter such as the thermal conductivity and heat transfer coefficient, this coefficient depends on different parameters, liquid type, flow velocity, heat flux.........

Nu is the function of Reynolds number and Prandtl number for forced convection and this reynolds number depends mainly on type of fluid and its viscosity, fluid velocity and its density. Prandtl number depends on specific heat also.

Thank you.

It can be more than 10,000,000

Nazaruddin S. .... Thanks.