Cauchy Number

Written by Jerry Ratzlaff on . Posted in Dimensionless Numbers

Cauchy number, abbreviated as Ca, a dimensionless number expressing the ratio of inertial force to compressibility force in a flow.  When the compressibility is important the elastic forces must be considered along with inertial forces.

Cauchy Number formula

 $$\large{ Ca = \frac {v^2 \; \rho } { B } }$$ $$\large{ Ca = \frac {v^2 \; \rho } { B } }$$

Where:

$$\large{ Ca }$$ = Cauchy number

$$\large{ B }$$ = bulk modulus elasticity

$$\large{ \rho }$$  (Greek symbol rho) = density

$$\large{ v }$$ = velocity of flow