What is the physical meaning of each term in the below equat

What is the physical meaning of each term in the below equation? DM_sys/Dt = partial differential/partial differential t integral rho*d Forall + CV integral rho*V*n*dA CS What is the physical meaning of each term in the below equation? DB_sys/Dt [D/Dt integral V*rho*d Forall] = partial differential/partial differential t integral V*rho*d Forall + CV integral V*rho*V*n*dA Volumetric Dilatation Rate =

Solution

12)first term is thetotal mass rate of change with time with velocity flux ( total derivative D/Dt = (d/dt + v.d/dv)M)

second term is due to the mass rate of change only

the third is the flux of mass thru the boundaries

13) same except this is momentum flux, D/Dt is the total derivative the other terms are the terms in the total derivative