I have been having this doubt for long. As by the first law dq=du+dw (neglecting KE and PE change). And we know that the work done by the system can be utilized in things (eg. boundary work, shaft work, shear work, paddle wheel work..etc).(adsbygoogle = window.adsbygoogle || []).push({});

For open flow system replacing dq=tds, we get,

tds=du+ dw (process should be reversible)

if we replace dw= pdv+(shaft work..etc), then we get,

tds=du+pdv+(shaft work..etc)

Why isn't the above equation valid, instead we use tds=du+pdv. Why are we considering only boundary work not other works?

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# How tds=du+pdv valid for open flow system?

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