Hi Jim,Yes, a hyperbaric gap would have greater pressure and this will change breakdown to some degree. As I understand the gap in question, it's not hyperbaric. If it were a hyperbaric gap, then you would certainly want to have the air flowing or at least the chamber pressurized equivalently (assuming we knew a decent ball park pressure for a typical hyperbaric gap).
One of the main points that Paschen showed was a curve identifying breakdown voltage with gap distance or pressure. It's a curve because of the molecular density of air and the probability of electrons getting from point A to B. The curve shows that as the pressure is decreased, breakdown voltage will drop (340V) and then will increase as pressure continues to drop (one of the strange phenomenons of the density of molecules in a low pressure environment. So what happens when we increase pressure? Well, breakdown voltage increases (unless were below that area of the curve described above).
In general, as the pressure is increased, the breakdown voltage should increase and mainly due to the product of d x p (distance and pressure). So if we double p, we should halve d for the same arc voltage. This is one of my main points about hyperbaric gaps I've tried to mention in the past regarding "cause of performance". Say we double the pressure and leave the gap distance unchanged. Did we just double our arc voltage? Yes we did. Is this being accounted for? I doubt it. I think were currently just applying a mechanical air force into the gap and observing the "performance". I'm not sure what the actual pressure differential is, but I have a hunch that the performance increase is due to the pressure causing the arc voltage to climb and thus the energy release to be greater (and thus, a hyperbaric gap at 0.2" cannot be compared to a blown gap at 0.2" with all else the same). If the pressure was known, then we could increase the blown gap distance equivalently, at which point, both gaps may perform similarly.
With the physics, it may be wise to identify and adjust the breakdown voltage of hyperbaric gaps under pressure on the workbench before running the TC (at least with an NST).
Take care, Bart Jim Mora wrote:
Hi, It seems to me that hyperbaric, curved gaps have some complicated aerodynamic physics....
_______________________________________________ Tesla mailing list Tesla@xxxxxxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla