Not hw.. My teacher wants us to understand this as it is important for reactor design.
A liquid is flowing through a tube of diameter D. The inner wall of the tube is maintained at a constant temperature of Ts. The liquid enters at a temperature of Tw1and leaves at a temperature of Tw2. The heat transfer coefficient for the liquid under the conditions of flow is h. The length of the tube is L. Assume steady state. Show that the rate at which heat is transferred from the wall to the flowing liquid is given by
q=h (π D L)((Ts−Tw1)−(Ts−Tw2))/ln((TS−Tw1)(TS−Tw2))
The Attempt at a Solution
I am trying to understand why the above equation is right, the only thing I can't seem to get is the ln of the bottom term, I understand the numerator, or atleast I think I do.