Mixing Moist Streams of Air

[DSoup]

Hi there,

I'm trying to determine how to go about attacking this problem

I have 2 streams of air mixing, and I'm trying to find the temperature and relative humidity of the third stream.

Stream 1: 2bar, 20C, 40%rh, and 1kg/s
Stream 2: 1bar, 20C, 4kg/s

So I know I can find all my values for the first stream, but the second stream doesn't give me enough to find it on the psychometric charts.

I've tried energy and mass balance equations but other than knowing the mass of the third air flow, I'm not sure how to attack this.

Thanks

 

[dvd]

if you don't know how much moisture is being carried in by approximately 4/5th of the flow, why bother? The problem is underdetermined.

 

[dvd]

Also, how are streams 1&2 smart enough to mix into stream 3 when they are at different pressures?

 

[DSoup]

Very, very, very true...I hadn't thought about the pressure differences, unless the third stream is in a much larger pipe so has a lower pressure.