Air flows through a combustion chamber held at 1145k and 101.3 kpa. oxygen diffuses through a 1.5 mm thick stagnant film of air to a flat carbon surface where it reacts instantaneously to form carbon monoxide. no reaction occurs in the gas film. the diffusivity of oxygen in the gas film is 1.30x10-4 m2 /s. what is the rate of oxygen diffusion to the surface?

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

What difference(s) did you notice using a pneumatic circuit over hydraulic circuit. explain why the pneumatic piston stumbles when it hits an obstacle.

Apipe with an outside diameter of 15 cm is exposed to an ambient air and surrounding temperature of -20°c. the pipe has an outer surface temperature of 65°c and an emissivity of 0.85. if the rate of heat loss from the pipe surface is 0.95 kw per meter of length, the external convective heat transfer coefficient (h) is: (a) 12.5 w/m"k (b) 18.6 w/mk (c) 23.7 w/mk (d) 27.9 w/mk (e) 33.5 w/mk