Mechanical Engineering - Hydraulics and Fluid Mechanics - Discussion

How will you determine a bulk modules by using mach numbers?

Bulk modulus is equal to the reciprocal of compressibility.

And Mach number is depends upon the compressibility.

Therefore to determine Mach number bulk modulus is required.

What is mach number?

E = density*dp/change in density. From bernoulli's equation if the order of pressure is same as the order of dynamic pressure then dp=density*velocity square/2. By substituting this in equation for bulk modulus we get. Change in density/density=1/2* (mach. No) square. Where mach number Ma=v/a.

9 velocity of fluid flow/velocity of sound in medium. If change in density/density is < 0. 05 we say fluid is incompressible. So Ma, 0. 33 for the flow to be compressible.

Mach no = inertia force / elastic force . It is a dimensionless quantity also defined as ratio of velocity of the flow / velocity of sound. Velocity of sound = sqrt (y. R.T ) y - gama.

M = v (ρ / E)1/2.

ρ-density;
E - Bulk Modulus of Elasticity.

If the value of mach number is 3, then the flow is called supersonic.

Mach number= square root ratio of inertia force to elastic force.

In determining elastic force we need bulk modulus.

Mach number = square root of ratio of inertia force to elastic force. We obtained K by this equation.

In fluid mechanics, Mach number (M or Ma) is a dimensionless quantity representing the ratio of speed of an object moving through a fluid and the local speed of sound.