Drow and explainthe use of vr data for calculating the final temperature during an isentropic process

The use of Vr data for calculating the final temperature during an isentropic process can be easily explained by taking an example.

Now let us take an example of Isentropic compression of Air in a car engine.

In this example consider air is compressed in a car engine from T₁ K and P₁ KPa in a reversible and adiabatic manner. If the compression ratio of this engine is V₁/V₂, determine the final temperature (T₂)

Here in the above example, the process is easily recognized as being isentropic since it is both reversible and adiabatic.

Now with the help of relative specific volume data (Vr) from the relative specific volume table, we can calculate the final temperature as:

Where a and b are the constants determined from boundary conditions, V_r1 is the relative specific volume at point 1 and V_r2 is the relative specific volume at point 2.

Now corresponding to temperature T₁ we can find the value of V_r1 from a relative specific volume table and then putting the values in the above equation for finding V_r2.

Now corresponding to V_r2 from a relative specific volume table we can determine the final temperature T₂.