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/ ASME's Mechanical Engine…ing Toolkit 1997 December / ASME's Mechanical Engineering Toolkit 1997 December.iso / earth / desert.exe / BNSODOPT.MO_ / BNSODOPT.MO
Text File  |  1995-04-11  |  2KB  |  57 lines
  1. #          External variables declaration
  2.  
  3. #               Hydraulic variables declaration               
  4.  
  5. var depth
  6. var flow
  7. var width 
  8. var crossect            #Cross sectional area
  9.  
  10. #               Input Data variables 
  11.  
  12. var T                   #Temperature
  13. var DO                  #Dissolved Oxygen
  14. var CBOD                #Carbonaceous Biological Oxygen Demand
  15. var NBOD                #Nitrogenous Biological Oxygen Demand
  16.  
  17. #          Constants declaration
  18.  
  19. daysec=84600.0          #Number of seconds in one day
  20. Kr=0.8/daysec           #CBOD removal rate (1/s)
  21. Kn=0.8/daysec           #NBOD removal rate (1/s)
  22. ka0=2.0/daysec          #Reareation coefficient (m/s^0.5)
  23. Ksod=0.5/daysec         #Sediment Oxygen Demand (g/m^2/s)
  24.  
  25. #          Local variables declaration
  26.  
  27. subst u=flow/crossect                   #Velocity (m/s)
  28. subst ft=1.016**(T-20.0)                #Temperature dependence of reareation
  29. subst ka=ka0*ft*sqrt(u/depth)           #Oxygen exchange at water-air interf.
  30.  
  31. subst Osat=14.652-0.41022*T+0.00799*T**2-0.000077774*T**3
  32.                                         #Saturation oxygen concentration
  33.  
  34. #          Initialization of components (setting of boundary conditions)
  35.  
  36. component L=CBOD        #Carbonaceous Biological Oxygen Demand
  37. component OX=DO         #Dissolved Oxygen
  38. component N=NBOD        #Nitrogenous Biological Oxygen Demand
  39.  
  40. #          Equations of DO-BOD reaction schemes
  41.  
  42. equation L=-Kr*crossect*L       #Exponential decay       
  43. equation N=-Kn*crossect*N       #Exponential decay
  44.  
  45. equation OX=ka*width*(Osat-OX)-Kr*crossect*L-Kn*crossect*N-width*Ksod
  46.         #Reaeration - CBOD consumption -NBOD consumption - SOD consumption
  47.  
  48. #          Optimization definition
  49.  
  50. constr CONST1=((OX>DO)&&(L<CBOD)&&(N<NBOD))     #Water quality constraint
  51. property COSTTOT                                #Operation cost parameter 
  52. objective COSTTOT                               #Objective function
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