Question: Water is flowing in a thin-walled copper tube under conditions such that the coefficient of convective heat transfer from water to the tube is given by the obviously empirical equation
Heat from the water flows through the tube wall to the surrounding atmosphere at a rate such that the convection coefficient from the outer surface of the tube to the atmosphere is given by another empirical equation
Assume the heat transfer resistance of the tube wall to be negligible. Find the minimum water velocity necessary to keep ice from forming on the pipe wall when the bulk water temperature is 35°F and the atmosphere is at - 25°F.