The friction coefficient for a boundary layer is given by the expression: Cf= = 1.32 √ Rex If the average flow velocity increases from an original state to a new state by a factor of 4.66, calculate the ratio of the Cf over its value at the original state.

Air at 20 °C flows over a flat aluminum plate at 30 m/s to cool electrical components on the other side. The plate measures 80 cm square.  The plate is to be kept below a constant temperature of 80 °C, but as it is a conductive metal, we can assume the plate has a constant temperature. Plot h along the plate, Find the average h for the whole plate and, Tell me Q, the total heat dissipated when the plate is at its maximum temperature.

a band moves at a speed V and is in contact with a surface of an oil tank with viscosity m. calculate the power in watts required if the belt is moving at 2.9 m / s over SAW 30W oil at 20 C with L = 2m, b = 60m, Nu = 329.0mm ^ 2 / s, rho = 0.9g / cm ^ 2 and h=3cm

Q2: A) Assuming linear variation of velocity in the boundary layer i.e. (u/u) =(y/6), up to y= 8 and then u = u, determine using the integral momentum equation, the boundary layer thickness. B) The temperature ratio: [T,-T)/(T, -T)] = sin (zy/0.015) in flow over a flat plate. If k = 0.03 W/m.K, determine the value of convective heat transfer coefficient.