(a) For a typical counterflow heat exchanger, explain
briefly the change in the effectiveness as the flow rate of the cold fluid is
decreased slowly from some initial value to near zero. Note that we are not
interested in transient effects, just a series of steady-state operating
conditions. See Fig. 1.50b for the initial temperature profiles.
(b) Explain briefly the effect on the temperature drop of
the hot fluid, Th.