Question

In a mass transfer operation, there is an analogy between __________.

• A. Mass, heat and Momentum
• B. Mass, heat and temperature
• C. Mass, heat and concentration
• D. Mass, heat and pressure

Hint:

Remember the classic "Triple Analogy of Transport Phenomena," which link the transport of Momentum (viscosity), Heat (thermal conductivity), and Mass (diffusion).

Answer 1

The Correct Option is A

Step 1: Understanding the Concept:
Transport phenomena in chemical and food engineering describe the physical mechanisms of three transport processes: momentum transfer (fluid flow), heat transfer (conduction/convection), and mass transfer (diffusion).
Because these processes share identical mathematical profiles, transport analogies are widely used to solve complex engineering problems.

Step 2: Detailed Explanation:
The transport of mass, heat, and momentum are governed by highly analogous physical laws:
1. Momentum Transport: Governed by Newton's Law of Viscosity:
\[ \tau = -\mu \frac{dv_x}{dy} \] 2. Heat Transport: Governed by Fourier's Law of Heat Conduction:
\[ q = -k \frac{dT}{dy} \] 3. Mass Transport: Governed by Fick's First Law of Diffusion:
\[ J = -D \frac{dC}{dy} \] These molecular transport equations all describe a flux being directly proportional to a driving force gradient.
This fundamental physical similarity forms the basis of Transport Analogies (such as the Reynolds Analogy, Prandtl Analogy, and Chilton-Colburn Analogy), which establish a direct quantitative relationship between Mass, Heat, and Momentum transport.
Using these analogies, food engineers can predict mass transfer coefficients (such as during food drying) from heat transfer coefficients or fluid friction factors, without conducting separate experimental measurements.

Step 3: Final Answer:
Therefore, in mass transfer operations, there is a direct analogy between Mass, heat and Momentum.