Fluid Mechanics: Density, Specific Volume, & Specific Weight

All objects have density, whether it's a solid, liquid, or gas. However, having an understanding of what density is, is very important for fluid mechanics, since density is used in a majority of fluid mechanics calculations. So what is density. Density is the mass of a substance over a certain unit volume. Density is represented by the greek letter rho. Refer to equation 1.

(1)

ρ = Density

m = mass

V = Volume

Specific volume on the other hand is the reciprocal of density. Refer to equation 2.

(2)

ν = Specific Volume

Finally, another aspect that is important to know for fluid mechanics is a fluid's specific weight. Specific weight relates the fluid's density and the effects of the gravitational constant. It is represented by the greek letter gamma. Refer to equation 3 to calculate specific weight.

(3)

γ = Specific Weight