EngMod2T

Post2T - The post processing software

Post2T: RPM Based Output.

Selecting to display "Performance and Efficiency Plots" from the main menu opens the following dialog box:

Once a file has been selected the following results are available:

  1. RPM         Simulated engine rpm
  2. P-av           Average engine power over the last three cycles (kW)
  3. Torque      The engine torque related to P-av.(Nm)
  4. Tex-AvC   Average temperature in center of exhaust (C)
  5. Tex-AvT   Average temperature at the trace position of exhaust (C)
  6. Power        Power per cylinder (kW)
  7. Imep           Indicated mean effective pressure per cylinder (bar)
  8. Bmep         Brake mean effective pressure per cylinder (bar)
  9. Fmep          Friction mean effective pressure (bar)
  10. Dratio         Delivery ratio per cylinder
  11. Purc            Purity of the mixture in the cylinder at exhaust port closure
  12. Seff            Purity of the mixture in the cylinder at transfer port closure
  13. Teff            Trapping efficiency per cylinder
  14. Ceff            Charging efficiency per cylinder
  15. BSFC          Brake specific fuel consumption per cylinder (kg/kWh)
  16. TC-av         Average maximum cylinder temperature per cylinder (C)
  17. TUBmax    Maximum unburned mixture temperature per cylinder (C)
  18. MaxDeg     Degrees after TDC where maximum cylinder pressure occurs per cylinder
  19. Timing        Ignition timing (BTDC)
  20. Delay          The user prescribed delay period in degrees (deg)
  21. Durat          The user prescribed combustion duration (burn period) in degrees (deg)
  22. TAF            Trapped Air/fuel ratio
  23. FuelFlow    The calculated fuel flow to produce the power with the AFR specified in cc/min)
  24. VibeDelay  The calculated delay period for a turbulent combustion model)
  25. VibeDurat  The calculated burn period for a turbulent combustion mode)
  26. VibeA        The calculated Vibe A value for a turbulent combustion model
  27. VibeM       The calculated Vibe M value for a turbulent combustion model

If the engine is turbocharged the following values are included:

  1. Boost         The simulated boost pressure (bar guage)
  2. BackPr       The simulated back pressure (bar guage)
  3. Pratio         The ratio between the boost pressure and the back pressure.
  4. TBoost        The simulated boost temperature at the boost measurement point
  5. TTurbine    The simulated turbine inlet temperature (C)

 

Total Power

This shows the predicted power curve for the Aprillia RSW125 and TZ250 1996 engines.

Power Range for the Two Engines

The "Power Range" is a concept developed by Frits Overmars and used to compare two or more engines by comparing not just available power but also the rpm band this usable power is in. The next graph shows that the RSW125 engine has more power available for all feasible power ranges than the TZ250 engine:

Power Range RPM Band

A spin-off of the Power Range concept is that it also gives the best maximum shift rpm and a minimum value the rpms should fall to:

 

Copyright Vannik Developments. All rights reserved.