Sir Henry Ricardo figured out what quench was and how it worked back in 1919. Here's a summary from Wikipedia but its best to actually read his work
"In 1919 Ricardo was studying the phenomena affecting the combustion within the petrol engine and the diesel engine. He realised that turbulence within the combustion chamber increased flame speed, and that he could achieve this by offsetting the cylinder head. He also realised that making the chamber as compact as possible would reduce the distance that the flame had to travel and would reduce the likelihood of detonation. He later developed the induction swirl chamber, which was an attempt to achieve orderly air motion in a diesel engine, the swirl being initiated by inclined ports and accentuated by forcing the air into a small cylindrical volume. Finally he developed the compression swirl chamber for diesel engines. This design embodied intense swirl with a reasonable rate of pressure rise and good fuel consumption.[10]"
The whole point of quench is to direct the unburnt mixture into the advancing flame front and improve the burn so as to increase the pressure rise in the cylinder.
