Mechanical Engineering - Compressors, Gas Dynamics and Gas Turbines - Discussion

Let r be the pressure ratio.
P2 =P1 x r.
P3 = P1 x r^2 (P3 and P1 are given, we can find r).

r^2 = P3/P1 = 16/1 = 16,
r = 4.

Delivery pressure at fourth stage P4 = P1 x r^3
= 1 x 4^3 = 64.

To determine the delivery pressure at the fourth stage, let's assume the compression ratio is the same for each stage. This is a common approach in multi-stage compression.

Given:
- Stage 1 pressure (P1) = 1 bar.
- Stage 3 pressure (P3) = 16 bar.

Let's find the compression ratio per stage (R). If P1 is the suction pressure of the first stage and P2 is the discharge pressure of the first stage (which becomes the suction pressure for the second stage), and so on:

P2 = P1 * R.
P3 = P2 * R = P1 * R^2,
16 = 1 * R^2.
R^2 = 16.
R = 4.

Now, let's find P4 (discharge pressure of the fourth stage):

P4 = P3 * R = 16 * 4 = 64 bar.

So, the delivery pressure at the fourth stage would be 64 bar.