Problem 13.22[Difficulty: 3]Given:Data on three tanksFind:Mass flow rate; Pressure in second tankSolution:The given or available data is:R=286.9J/kg.Kk=1.4At=1cm2We need to establish whether each nozzle is choked. There is a large total pressure drop so this is likely.However, BOTH cannot be choked and have the same flow rate. This is because Eq. 13.9a, below(13.9b)indicates that the choked flow rate depends on stagnation temperature (which is constant) but alsostagnation pressure, which drops because of turbulent mixing in the middle chamber. Hence BOTH nozzlescannot be choked. We assume the second one only is choked (why?) and verify later.Temperature and pressure in tank 1:T01=308Kp01=650kPaWe make a guess at the pressure at the first nozzle exit:pe1=527kPaNOTE: The value shown is the final answer! It was obtained using Solver!This will also be tank 2 stagnation pressure:
This is the end of the preview.
access the rest of the document.