Consider a finned-tube, cross-flow heat exchanger with both fluids unmixed. this heat exchanger is used to heat pressurized water with a flow rate of 1 kg/s from 35 to 125 c using exhaust gas. the exhaust gas enters the heat exchanger at 300 c and exits at 100 c. the overall heat transfer coefficient based on the gas-side area is uh=100 w/m2 .k. find the required gas-side heat transfer area, ah. use both ntu and lmtd methods and compare the results.

Line joining liquid phase with liquid and solid phase mixture is known as: a) liquidus b) solidus c) tie line d) none of the mentioned

Steel is coated with a thin layer of ceramic to protect against corrosion. what do you expect to happen to the coating when the temperature of the steel is increased significantly? explain.

Aloaded platform of total mass 500 kg is supported by a dashpot and by a set of springs of effective stiffness 72 kn/m. it is observed that when the platform is depressed through a distance x = 12.5 cm below its equilibrium position and then released without any initial velocity; it reaches its equilibrium position in the shortest possible time without overshoot. find the position and velocity of the loaded platform 0.10 sec. after its release. if a further load of 400 kg is added to the platform, find, i) the frequency of damped vibrations, and i) the amplitude of vibration after 2 complete oscillations, given that the initial amplitude is 15 cm.