The local skin friction coefficient (Cf, x) for external turbulent convection over a flat plate is given by CCff ≅ 0.059 (xx)0.2 Where, Rex is the Reynolds number at a particular point given by µ rhoVL Re = rho is the density of the fluid, V is the velocity of fluid, L is the length on the plate of the point of interest, (equivalent to x), and μ is the viscosity of the fluid. Write a pseudo code that calculates the skin friction coefficient for a user input rho, V, L and μ.

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?