Source of error:
- Error in reading data since this done by human eye.
- In accurate in reading velocity head by pitot tube.
Discussion and conclusion:
Comments:
- Some tubes embedded in air flowing path to increase its speed due to decrease the working area to half.
- When throttle area decrease the mass flow rate inside decrease so the velocity of air decreases.
- Since the absolute slope increase with throttle opening increases, the heat transfer coefficient increases
this lead to increasing in Nusselt number.
- Reynolds number increases with throttle opening increases due to increase in velocity of air.
- if the heat transfer medium change with another fluid the thermal conductivity parameter will control the
process, the changing in this parameter lead to changing in Nusselt number .
For Reynolds number it will be change since the viscosity of new fluid differs than air.