The recorded pressure diagrams have one issue that needs addressing.
Where is the Exhaust sensor in relation to the piston.
If the distance /time factor is not taken into account by the software , then that spike that is shown at tdc , wont be anywhere near tdc.
If the sensor is 150mm from the piston , then that spike , a snapshot in time ,will have taken a significant number of degrees of crank rotation to arrive at that point.
A function of the wave speed , and rpm.
This is why Neels code has a fixed wave snapshot at the port face , then a second wave showing whats happening at a set distance from the port.
In this case the pressure diagram is meaningless , but other metrics such as wave Mach can be observed.
Many highly reputable SAE papers on engine simulation Vs real data , including those of Blair and Fleck et al from Queens , have been presented showing wave forms where this time smear is completely ignored.
And if one wants to get really pedantic , the pressure traces , should also be labelled as rightward or leftward propogated ie is the pressure rise coming from the port , or the reflected returning pulse.
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