[Edeluc]

Dear Forum users,

I do have a question regarding the turbulence in a Rapid Compression Expansion Machine (RCEM). The particluar one I do have in mind can be found here.
I want to get clear on the following experimental procedure:

1.) Fixing piston and inserting mixture
The basic idea is to fix the piston (which is not connected by any rod but operated with pressure) at the top dead centre of the machine and to insert a certain ignitable mixture. Then the mixture is given some time to "calm down" - By that I assume a calm flow field and no turbulence.

2.) Igniting the mixture and moving down the piston
After the flow field and turbulence properties have reached the desired calm conditions, I want to ignite the mixture and move down the piston according to the volume change the gas is experiencing - This gives me a constant pressure in the chamber, when we look at the equation of state (pressures are low enough to disregard effects like co-volume and Van-der-Waals forces):

p * V = m * R * T

If the volume V increases and the temperature T increases and I do assume m and R to be constant then the pressure should stay the same.

3.) Determining turbulence and flow field
The flame now pushes "forward" due to volume dilatation and therefore brings a motion which is more or less compensated by the piston moving away accordingly.


My current understanding of this:
In my understanding this procedure should enable a constant pressure combustion with (if everything is timed correctly) no turbulence and no flow field.


My questions to you now are:
1.) Is my theoretical understanding of this process correct?
2.) Is it correct that if we would have now combustion and assume no chemical effects and the piston moves down, would we induce a flow field? Or stating it differently: Would there be a flow field if there is now combustion in the above experiment?