Aliquid drug, with the viscosity and density of water, is to be administered through a hypodermic needle. the inside diameter of the needle is 0.27 mm and its length is 50 mm. determine (a) the maximum volume flow rate for which the flow will be laminar (re < 2300), (b) the pressure drop required to deliver the maximum flow rate, and (c) the corresponding wall shear stress

Apreheater involves the use of condensing steam at 100°c on the inside of a bank of tubes to heat air that enters at 1 atm and 25°c. the air moves at 5 m/s in cross flow over the tubes. each tube is 1 m long and has an outside diameter of 10 mm. what is the minimum value of nl needed to achieve an outlet temperature of t 75 c? what is the corresponding pressure drop across the tube bank?