EngMod2T

Post2T - The post processing software

Post2T: Crank-Angle or Degree Based Output.

Selecting to display "Thermo- and Gasdynamic Traces" from the main menu opens the following dialog box:

The top left lists the 8 types of trace files that can be selected:

  1. Pressure Traces - this allows the pressure to be recorded in any pipe, duct, port, plenum, cylinder and box
  2. Mach Indexes - this traces the value of the mach index in any port or pipe and past any valve
  3. Temperature Traces - this allows the temperature to be recorded in any pipe, duct, port, plenum, cylinder and box
  4. Wave Traces - this allows the left and right moving waves to be independently displayed in any duct, pipe or port
  5. Purity Traces - this displays the purity of the gas in any port, duct, pipe or cylinder
  6. Combustion Traces - this displays the combustion characteristics, depending on the combustion model chosen
  7. Load Traces - this displays the loads on the bearings, rods and pistons if the optional mechanical input was used
  8. Mass Flow Traces - this displays the mass flow past any valve, through any position in a pipe or port and through the turbocharger compressor, turbine and wastegate
  9. Turbocharger Traces - this displays the various turbocharger results

 

The following graphs are just a small example of the outputs that are available.

1. Pressure Traces

The following is a sample of pressure traces. It shows the transfer port, cylinder (limited to 4bar) and exhaust port pressures for an Aprilia RSW125 engine with port event lines:

2. Mach Traces

This figure shows the mach traces for the exhaust port for an Aprilia RSW125 engine. The two traces show the mach values through the port opening (ExPMach), and about a 100mm (user defined position) from the piston (ExMach). It shows that the flow through the window is sonic for the initial blowdown period and also for the "stuffing" period.

3. Temperature Traces

The in cylinder temperatures are shown. The black line shows the mean temperature inside the cylinder (TCyl), the red line the temperature of the unburnt mixture (TUnBurnt), and the green line shows the burnt mixture temperature (TBurnt). It is also possible to display the temperature in any point of any plenum or duct.

4. Wave Traces

This shows the left and right moving waves at the exhaust window, which explains why they are the same when the window is closed. Note how the blowdown pulse (PepRight) differs from the reflected pulse (PepLeft) during the window open period.

5. Purity Traces

The purity of the cylinder is an indication of how good the scavenging was and what the purity of the plugging pulse was.

6. Combustion Traces

The traces shown here are the theoretical and calculated squish velocities.

7. Load Traces

The loads on the big-end bearings, main bearings and piston skirt can be simulated if the optional crankshaft data (and if required the balance shaft data) is entered.

8. Mass Flow Traces

This shows the mass flow in the transfer port window and the exhaust port window.

9. Turbocharger Traces

This shows the pressure ratios across the the compressor and the turbine and waste gate.

 

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