Yeah, the same def' applied to highly tuned 2-stroke G.P. bikes, pumping ~15bar BMEP,saviour stivala wrote: ↑27 Apr 2022, 05:06‘spocom – spontaneous combustion’ is a type of ‘uncontrollable’ combustion that is avoided at all cost by engine designers. Modern formula 1 engine design trends aims to achieve a ‘rapid’ or as fast a combustion as can be short of it being ‘spontaneous’.
Yes, but I think the prechamber jets create the main chamber pressure rise first to "autoignite" the end gases.
I don’t see the jets coming. It is just the shockwave from the pre-chamber which travel even faster.johnny comelately wrote: ↑30 Apr 2022, 12:12Yes, but I think the prechamber jets create the main chamber pressure rise first to "autoignite" the end gases.
It is the control for reliable predictability of the autoignition phase that is key
I'd like to see the infrared cam before backing that statement. If it is a vortex loop, it could be in a quasi-plasma state, and we only see the visible light when it breaks down at the cylinder wall.NL_Fer wrote: ↑30 Apr 2022, 16:10I don’t see the jets coming. It is just the shockwave from the pre-chamber which travel even faster.johnny comelately wrote: ↑30 Apr 2022, 12:12Yes, but I think the prechamber jets create the main chamber pressure rise first to "autoignite" the end gases.
It is the control for reliable predictability of the autoignition phase that is key
The prechamber spark initiation is what gives the predictability and therefore control.NL_Fer wrote: ↑30 Apr 2022, 16:10I don’t see the jets coming. It is just the shockwave from the pre-chamber which travel even faster.johnny comelately wrote: ↑30 Apr 2022, 12:12Yes, but I think the prechamber jets create the main chamber pressure rise first to "autoignite" the end gases.
It is the control for reliable predictability of the autoignition phase that is key
Another release by Honda suggest that they use a form of plasma jet that extends to the cylinder walls first. This initial Jet of free radicals doesn't ignite the fuel mixture until it slows down near the walls, or something like that.
5.11.1 Ignition is only permitted by means of a single ignition coil and single spark plug per cylinder. No more than five sparks per cylinder per engine cycle are permitted.PlatinumZealot wrote: ↑01 May 2022, 17:13Another release by Honda suggest that they use a form of plasma jet that extends to the cylinder walls first. This initial Jet of free radicals doesn't ignite the fuel mixture until it slows down near the walls, or something like that.
My guess is that is must be something in the fuel that creates these long-lived free radicals.
It's not conventional plasma ignition. Just as much as the spark plasma on the spark plug is not a conventional plasma ignition. Both have charged gasses but the plasma ignition is steady high voltage streams. Plasma ignition uses specific hardware and voltage to achieve this.johnny comelately wrote: ↑01 May 2022, 23:295.11.1 Ignition is only permitted by means of a single ignition coil and single spark plug per cylinder. No more than five sparks per cylinder per engine cycle are permitted.PlatinumZealot wrote: ↑01 May 2022, 17:13Another release by Honda suggest that they use a form of plasma jet that extends to the cylinder walls first. This initial Jet of free radicals doesn't ignite the fuel mixture until it slows down near the walls, or something like that.
My guess is that is must be something in the fuel that creates these long-lived free radicals.
The use of plasma, laser or other high frequency ignition techniques is forbidden
Combustion consists of various radical chain reactions that the singlet radical can initiate. The flammability of a given material strongly depends on the concentration of free radicals that must be obtained before initiation and propagation reactions dominate leading to combustion of the material. Once the combustible material has been consumed, termination reactions again dominate and the flame dies out. As indicated, promotion of propagation or termination reactions alters flammability. For example, because lead itself deactivates free radicals in the gasoline-air mixture, tetraethyl lead was once commonly added to gasoline. This prevents the combustion from initiating in an uncontrolled manner or in unburnt residues (engine knocking) or premature ignition (preignition).
I dont understand chemistry well enough to have an opinion on the ozone production and fuel interaction with that.