Download Aptitude Crack
img not found img not found

Heat Transfer

Q1:

The film co-efficient between condensing vapour and metal wall increases with

A increasing temperature of the vapour.

B decreasing temperature of the vapour.

C increasing viscosity of the film of condensate.

D increasing temperature drop.

ANS:A - increasing temperature of the vapour.

The film coefficient between condensing vapor and a metal wall typically increases with increasing temperature of the vapor. Here's why:

  1. Temperature Difference: The film coefficient represents the effectiveness of heat transfer between the condensing vapor and the metal wall. A higher temperature difference between the vapor and the wall results in greater driving force for heat transfer, leading to higher heat transfer rates and thus a higher film coefficient.
  2. Increased Heat Flux: As the temperature of the vapor increases, the vapor becomes more energetic, which can lead to higher heat flux at the surface. This higher heat flux requires a higher film coefficient to transfer the increased heat efficiently to the metal wall.
  3. Enhanced Turbulence: Higher vapor temperatures can promote turbulence in the boundary layer near the surface, which can increase the mixing and enhance heat transfer. This increased mixing results in a higher film coefficient.
Therefore, the film coefficient typically increases with increasing temperature of the vapor, as it indicates more efficient heat transfer between the condensing vapor and the metal wall.



img not found
img

For help Students Orientation
Mcqs Questions

One stop destination for examination, preparation, recruitment, and more. Specially designed online test to solve all your preparation worries. Go wherever you want to and practice whenever you want, using the online test platform.