Topic: Heat Transfer
The Rayleigh number Ra, is defined as: (where Gr is Grashoff Number, Pr is Prandtl Number and Re is Reynold Number)
- A. Ra = Re * Pr
- B. Ra = Gr * Re
- C. Ra = Gr * Pr
- D. Ra = Gr * Pr / 4
Answer: C. Ra = Gr * Pr
Explanation: The Rayleigh number (Ra) is a dimensionless number associated with buoyancy-driven flow, also known as free or natural convection. It is defined as the product of the Grashoff number (Gr) and the Prandtl number (Pr), hence Ra = Gr * Pr.