That's correct: the term "
inpingement" describes an effect by which a jet of water suddenly strikes an object. The theory is that the striking creates a very small area where the water is thrown into turbulence (ref: Reynolds) and thereby reduces the thermal resistance, which allows the CPU heat to be transferred more efficiently.
The square cup is indeed better: the whole principle of Cathar's "
Cascade" is based on what I described (
here) as a double inpingement effect, where it first occurs at the bottom of the cup, then occurs again on the side wall. That gives you minimal thermal resistance, precisely where it is needed: right over the core. The round cup virtually eliminates the second inpingement effect.
It's going to be extremely difficult to beat this design, because it already maximizes all of the flow action of the water. Personally, I'll be trying it out with two Johnson pumps, and I'm hoping to throw the water into turbulence, as it enters the small tubes: something that I've never seen anyone do before, because the pressures involved are rather high.
Since the block will have brass microtubes, it should have a smooth inner surface, reducing the friction, and restriction of flow. Normally we're not concerned about that, because in non-turbulent flow, the surface smoothness of the tubing has little to no effect on the flow resistance.
It may sound crazy, but I'm going for the Chuck Yeager factor here
