Bulk Modules

 

The definition for the bulk modules is as follows:

 

The resulting bulk modulus of the oil - air mix is:

 

where,  is the air volume fraction of the mix. The air and the oil states are calculated separately.

 

In isothermal case, assume that the bulk module of the air formulated as:

 

In isentropic case, assume that the bulk module of the air formulated as:

 

where,  is the ratio of specific heat.

 

Assume that the bulk modulus of the oil formulated as:

 

where,

      is the pressure coefficient

      is the bulk modulus at the reference pressure

 

The air volume can be calculated as follows:

 

where,  is the ratio of specific heat.

 

The oil volume can be calculated as follows:

If ,

 

If ,  

 

 can be calculated as follows: