Mixing of two air flow at different pressure

AI Thread Summary
To determine the final pressure (P3) and temperature (T3) of two air flows mixed adiabatically, Bernoulli's equation should be applied twice for different sections of the flow. The system requires known pressure and velocities to solve the equations, as there are more unknowns than equations. A control volume around the mixing point helps analyze the energy exchange, where the enthalpy out equals the enthalpy in. The temperature of the mixed flows will equalize, allowing for calculations of energy exchange to find the final enthalpy for each component. This approach effectively addresses the mixing of air flows with differing pressures, temperatures, and mass flow rates.
Devang Marvania
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Hi Friends! Here is my query :

I have two source of air supply with different pressures, temperatures and with different mass flow rates.
Input 1: P1,T1,m1.
Input 2:P2,T2,m2.
Output: P3,T3,m3.
P,T and m refers to pressure, temperature and mass flow rate respectively. If the mixing is being done in adiabatic way how to obtain final pressure and final temp of air(P3,T3).
Open the link
https://drive.google.com/file/d/0B5HXdL19FoVMQnFVUGhiZEFZUU0/view?usp=sharing

https://drive.google.com/file/d/0B5HXdL19FoVMQnFVUGhiZEFZUU0/view?usp=sharing
 
I don't know if you still need an answer to this but maybe someone else would like to see an answer too.

You just need to use Bernoullie's equation twice. Once for two of the three sections and another time for two sections from which one must be different than those sections from the first equation. And of course you'll need to have some given pressure and velocities since, obviously, you can't solve a system of two equations with nine unknowns.
 
Put a control volume around the mixing T. The enthalpy out is equal to the enthalpy in.

You can treat the two flows separately. There is some amount of energy lost by the flow coming in at a higher temperature and gained by the flow coming in at a lower temperature. The temperature of the two are of course, the same after they've mixed. So just calculate how much energy is exchanged so that the temperatures are the same and you have the enthalpy out for each component.
 
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