What is the Ideal Gas Law and its Application to Specific Volume?

[Su Solberg]

Hi, everyone

Since specific Volume is 1/density, How come this web can provide a decreasing Specific Volume of Air when the temperature increase?

http://www.engineeringtoolbox.com/air-properties-d_1257.html

Thanks for your help.

 

[aerospaceut10]

Ideal gas law

P = density*R*Temperature

I'm assuming Pressure is kept as a constant value.

 

[nvn]

Su Solberg: v_r = relative specific volume = v/v_o, and applies only to isentropic (constant entropy) processes for an ideal gas, where v = specific volume = 1/rho, and v_o = specific volume at a zero reference level for enthalpy and internal energy. The zero reference level for enthalpy and internal energy is typically taken at 0 K and 1 atm (absolute). I do not fully understand v_o, nor my above description of v_o, so hopefully someone else can explain v_o better.

However, the v_r column of the table you cited is grossly incorrect. Please use another source, not the erroneous web page cited. Furthermore, that web page nebulously does not state its zero reference level.