From b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b Mon Sep 17 00:00:00 2001 From: priyanka Date: Wed, 24 Jun 2015 15:03:17 +0530 Subject: initial commit / add all books --- 572/CH12/EX12.6/c12_6.sce | 83 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 83 insertions(+) create mode 100755 572/CH12/EX12.6/c12_6.sce (limited to '572/CH12/EX12.6/c12_6.sce') diff --git a/572/CH12/EX12.6/c12_6.sce b/572/CH12/EX12.6/c12_6.sce new file mode 100755 index 000000000..675a8e27d --- /dev/null +++ b/572/CH12/EX12.6/c12_6.sce @@ -0,0 +1,83 @@ +//(12.6) At steady state, 100 m3/min of dry air at 32C and 1 bar is mixed adiabatically with a stream of oxygen (O2) at 127C and 1 bar to form a mixed stream at 47C and 1 bar. Kinetic and potential energy effects can be ignored. Determine (a) the mass flow rates of the dry air and oxygen, in kg/min, (b) the mole fractions of the dry air and oxygen in the exiting mixture, and (c) the time rate of entropy production, in kJ/K . min + +//solution + +//variable initialization +T1 = 32 //temperature of dry air in degree celcius +p1 = 1 //pressure of dry air in bar +AV1 = 100 //volume rate of dry air in m^3/min +T2 = 127 //temperature of oxygen stream in degree celcius +p2 = 1 //pressure of oxygen stream in bar +T3 = 47 //temperature of mixed stream in degree celcius +p3 = 1 //pressure of mixed stream in bar + +//part(a) +Rbar = 8314 //universal gas constant +Ma = 28.97 //molar mass of air +Mo = 32 //molar mass of oxygen + +va1 = (Rbar/Ma)*(T1+273)/(p1*10^5) //specific volume of air in m^3/kg +ma1dot = AV1/va1 //mass flow rate of dry air in kg/min + +//from table A-22 and A-23 +haT3 = 320.29 //in kj/kg +haT1 = 305.22 //in kj/kg +hnotT2 = 11711 //in kj/kmol +hnotT1 = 9325 //in kj/kmol + +modot = ma1dot*(haT3-haT1)/[(1/Mo)*(hnotT2-hnotT1)] //in kg/min +printf('the mass flow rate of dry air in kg/min is: %f',ma1dot) +printf('\nthe mass flow rate of oxygen in kg/min is: %f',modot) + +//part(b) +nadot = ma1dot/Ma //molar flow rate of air in kmol/min +nodot = modot/Mo //molar flow rate of oxygen in kmol/min + +ya = nadot/(nadot+nodot) //mole fraction of air +yo = nodot/(nadot+nodot) //mole fraction of oxygen + +printf('\n\nthe mole fraction of dry air in the exiting mixture is: %f',ya) +printf('\nthe mole fraction of dry oxygen in the exiting mixture is: %f',yo) + +//part(c) +//with the help of tables A-22 and A-23 +sanotT3 = 1.7669 //in kj/kg.K +sanotT1 = 1.71865 //in kj/kg.K +sbarT3 = 207.112 //in kj/kmol.K +sbarT2 = 213.765 //in kj/kmol.K + +sigmadot = ma1dot*[sanotT3-sanotT1-(8.314/Ma)*log(ya)] + (modot/Mo)*[sbarT3-sbarT2-8.314*log(yo)] +printf('\n\nthe time rate of entropy production, in kJ/K . min is: %f',sigmadot) + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + + -- cgit