[AliAli]

I used bulk modulus approach for defining the density for the model of piston movement.The bulk modulus is as a function of pressure (table below), then I used an expression for calculating densiyt as a function of variable bulk modulus and constant speed of sound (1500 m/s). Table: bulk modulus versus pressure at 68 F degree for water (from fluid mechanics book)

Pressure (Psi) Bulk modulus (Psi)
.................. ........................
15 ------------320,000
1,500 -------- 330,000
4,500 ---------348,000
15,000 --------410,000

But, from the slover, i observed that the speed of sound is equal to (578) in the average scale information, i think that is not true. Could someone help please? if it is not the right way for defining the bulk modulus apporach, could someone tell me how to define it??? Thanks in advance.