Laminar flow normally persists on a smooth flat plate until a critical reynolds number value is reached. however, the flow can be tripped to a turbulent state by adding roughness to the leading edge of the plate. for a particular situation, experimental results show that the local heat transfer coefficients for laminar and turbulent conditions are:

h lam ( x ) = 1.74 w / m^ 1.5 * k x^ − 0.5

h turb ( x ) = 3.98 w / m^ 1.8 * k x ^− 0.2

calculate the average heat transfer coefficients for laminar and turbulent conditions for plates of length l = 0.1 m and 1 m.

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.

Shafts are machine elements that are used to a) carry axial loads b) direct shear loads c) transmit power d) rotate at constant speed e) none of the above circular and square shafts subjected to the same torque under the same circum behave a) the same way b) almost the same way