Air is being heated with hot oil in banks. The tubes are made of an alloy with thermal conductivity (K= 310 W/mk). The hot oil is at a temperature of 125 degree Celsius and flows inside the tubes. The air flows on the outside. Air enters at 20 degrees Celsius with a mean velocity of 5.8 m/s and at 1 atm. The tubes are thin wall with a diameter of 2cm. The tubes are arranged in staggered arrangement with longitudinal transverse pitches of SL-ST= 5cm. There are 21 rows in the flow direction with 8 tubes per row. Assume an exit temperature of the air from the tube bank as 80 degrees Celsius and based on this, determine the following per unit length of the tubes. Note that you are not supposed to perform any iterations. Just perform calculations for the first iteration with starting temperature of 80 degrees Celsius. For this iteration compute: a) New exit temperature of air from the tube bank b) Rate of heat transfer per unit length of the tubes c) Pressure drop for air flow across the tubes

I am attaching both questions for 4 and 5 with the question in the image. thank you. NOTE : So the last person answered this question WITHOUT refencing the answer for whether question 4 or 5 answeres were given, so i am asking for question 5(or the answer for the question that was NOT solved because it was not referenced.) These were the following answers given to me from the last person on bartleby who answered my question without referencing whether it was the answer for question 4 or 5.  1 pass 2 fail 3 fail 4 pass

I need these three parts answered, if you are unable to answer all three parts please leave it for another tutor to answer, thank you.

What’s the correct answer for this please?