An experiment is designed to measure the heat transfer from a gas stream at temperature 400 F to the outer surface of a tube of 1 inch i.d. and 2inches o.d. Coolant is passed through the bore at a known rate so that the heat transfer coefficient on the inner surface is fixed at 20 Btu/ft2 h R.
Determine the heat transfer coefficient from the gas to the tube surface. What is the percentage error in this experimental value for an estimated ±5% error in the inner surface heat transfer coefficient and a ±2 F error in the measured surface temperature?