In fluid dynamics, compressibility is one of the major factors that determine the nature of fluid. This measurement is necessary to understand the response for pressure change during compression on the gases.It is denoted by (1/ K).

Let us consider initial volume of gas (before compression) be V

Final volume of gas (after compression) V – dV as shown in Fig. 1.4


Compressible Fluids” = C


So, Change in volume of gas will be-

(V – dV)– V = – dV

Volumetric Strain

Volumetric strain of fluid can be defined as the ratio of change in volume to the initial volume. Mathematically, it can be written as-

Volumetric Strain = – dV/ V

Bulk modulus of elasticity

It can be defined as the ratio of change in pressure to volumetric strain. It is denote by K.


K = dp/((– dV/ V))

1/K = 1/(dp/((– dV/ V)))

1/K = ((– dV/ V))/dp


1/K = (( dρ/ ρ))/dp


1/K = dρ/(ρ dp)


As compare to liquids, compressibility of gases is high.



Links of Previous Main Topic:-

Links of Next Mechanical Engineering Topics:-

Submit Your Assignment


Customer Reviews

My Homework Help
Rated 5.0 out of 5 based on 510 customer reviews at
Rating View

Trusted Reviews from Google

Trusted Reviews from trustpilot