A sheet of steel 1.5 mm thick has nitrogen (N2) atmospheres on both sides at 1200°C and is permitted to achieve steady-state diffusion condition. The diffusion coefficient for N2 in steel at this temperature is 6 ´ 10-11 m2 /s, and the diffusion flux is found to be 1.2 ´ 10-7 kg/m2 -s. Also, it is known that the concentration of N2 in the steel at the high-pressure surface is 4 kg/m3 . How far into the sheet from the high-pressure side will the concentration be 2.0 kg/m3 ? Assume a linear concentration profile.

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

The mass flow rate of the fluid remains constant in all steady flow process. a)- true b)- false

Apump is used to circulate hot water in a home heating system. water enters the well-insulated pump operating at steady state at a rate of 0.42 gal/min. the inlet pressure and temperature are 14.7 lbf/in.2, and 180°f, respectively; at the exit the pressure is 60 lbf/in.2 the pump requires 1/15 hp of power input. water can be modeled as an incompressible substance with constant density of 60.58 lb/ft3 and constant specific heat of 1 btu/lb or. neglecting kinetic and potential energy effects, determine the temperature change, in °r, as the water flows through the pump.