SBA Invent Logo

Fluid Mechanics: Density, Specific Volume, & Specific Weight



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.

Density Equation (1)

ρ = Density

m = mass

V = Volume


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

Specific Volume Equation (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.

Specific Weight Equation (3)

γ = Specific Weight




If you found this information helpful please donate to show your support.


Feedback and Recommendations