Air at 10 C enters a 12-cm-diameter and 5-m-long pipe at a rate of 0.065 kg=s. The inner surface of the pipe has a roughness of 0.22 mm, and the pipe is nearly isothermal at 50 C. Determine the rate of heat transfer to air using the Nusselt number relation given by (a) Eq. 19{79 and (b) Eq. 19{84. Evaluate air properties at a bulk mean temperature of 20 C. Is this a good assumption?

Explain the difference laminar and turbulent flow. explain it with the shear stress and the velocity profiles.

Apiston-cylinder with a volume of 0.25 m3 holds 1 kg of air (r 0.287 k/kgk) at a temperature of 100 c. heat transfer to the cylinder causes an isothermal expansion of the piston until the volume triples. how much heat is added to the piston-cylinder?

Amixture of slurry and mud is to be pumped through a horizontal pipe of diameter 500 mm. the fluid behaves as a bingham plastic with a yield stress of 30 pa and viscosity 0.04 pa.s. describe the effects of the shear stress through a transverse section of the pipe by plotting the variation in shear stress and velocity profile: (i) just before the slurry starts to move (ii) as the slurry flows when the pressure gradient is double that in part (i)