The Grash of number, Gr is defined as:(where g is gravitational acceleration, $$\beta$$ is volumetric thermal expansion coefficient, $$\triangle T$$ is temperature difference, L is characteristic length, $$\mu$$ is the viscosity and v is kinematic viscosity.

A

$$\frac{g \beta \triangle TL^3}{\mu^2}$$

B

$$\frac{\rho^2 g \beta \triangle TL^3}{\mu^2}$$

C

$$\frac{g \beta \triangle TL^3}{v^2}$$

D

$$\frac{g \beta \triangle TL}{v^2}$$