Test: Heat Transfer By Forced Convection - 2 - Mechanical Engineering MCQ

For laminar flow in a tube for constant wall temperature Nusselt number is approximately equal to

If Nusselt number is 400, Stanton number is 0.5 and Reynold’s number is 40, then Prandtl number will be

The velocity and temperature distribution in a pipe flow are given by U(r) and T(r). If u_m is the mean velocity at any section of the pipe, the mean temperature at that section is

A fluid flowing over aflat plate has the following properties:
Dynamic viscosity = 25 x 10^-6 kg/ms
Specific heat = 2 kJ/kgK
Thermal conductivity = 0.05 W/mK

The hydrodynamic boundary layer thickness found to be 0.5 mm. The thickness of thermal boundary layer would be

For a laminar flow of air (Pr = 0.71) over a flat plate at zero incidence, the thickness of the velocity boundary layer δ and the hydrodynamic boundary layer δ_t are such that

Heat is lost from a 100 mm diameter steam pipe placed horizontally in ambient at 30°C. If the Nusseit number is 25 and thermal conductivity of air is 0.03 W/mK then the heat transfer coefficient will be

Heat transfer coefficients for free convection in gases, forced convection in gases and vapours and for boiling water lie respectively in the range of