PROFESSIONAL MOTORSPORT

SIMULATION SOFTWARE

Combining the 4 phases of the combustion process

With the two zone burn sequence simulated, the complete compression and power stroke is simulated.

Combining these with the previous calculated exhaust and intake stroke gives a pressure diagram over the full 720 camshaft degrees. Hereby one automatically include the pumping losses of the exhaust and intake stroke.

Model behaviour through rpm range

Figure showing 720 degrees cylinder pressure diagram at 2500 rpm
Figure showing 720 degrees cylinder pressure diagram at 4500 rpm
Figure showing 720 degrees cylinder pressure diagram at 6500 rpm
Figure showing 720 degrees cylinder pressure diagram at 8500 rpm

Within the pressure diagram, there are different colours used to indicate the different phases. A white line means that at least one valve is open.

The dark grey line represents the compression and expansion stroke, in both cases with all valves closed. The orange line is the burning phase of the mixture.

In the four figures on the right, you see the change in behaviour due to different engine rpm.

The top figure is the pressure diagram @ 2500 [rpm]. At this rpm the pumping losses are very small. Furthermore, because fill rate is relatively low, the end pressure is lower compared to the other figures.

In the second figure, representing 4500 [rpm], the pumping losses increase, as does the end pressure due to the higher fill rate.

The third figure, at 6500 [rpm], the engine reaches peak torque. It also reaches the highest end pressure due to highest fill rate. it can be seen that this is also caused by the exhaust pulling the gasses out of the cylinder.

In the last figure, at 8500 [rpm] which is beyond peak power, the fill rate is significantly reduced due to the intake and exhaust dynamics. The pumping losses increase further.

Click in the fill rate figure

Figure the cylinder fill rate out of the simulation as a function of engine rpm
Figure showing 720 degrees cylinder pressure diagram at 6500 rpm

By clicking in either the power/torque graph or the fill rate graph, one can select the rpm of which one would like to see.

In first instance LapSim will show the intake dynamics for this rpm. However by clicking in the graph showing the dynamics, this changes in the 720 degrees pressure graph.

Within the pressure diagram the momentary ignition, torque and burn duration is shown.

You can now click in either the fill rate figure or the power/torque figure to select a different rpm.