Question

The average heat transfer co-efficient for laminar film condensation on vertical surface is inversely proportional to (where, \( \Delta T \) = temperature drop across condensate film)

• A. \( (\Delta T)^2 \)
• B. \( \Delta T \)
• C. \( (\Delta T)^{1/2} \)
• D. \( (\Delta T)^{1/4} \)

Hint:

In laminar film condensation: \( h \propto (\Delta T)^{-1/4} \)

Answer 1

The Correct Option is D

According to Nusselt’s theory, the condensation heat transfer coefficient is:
\[ h \propto \left( \frac{k^3 \rho^2 g h_{fg}}{\mu L \Delta T} \right)^{1/4} \]