Doug, to me it looks as if your questions are more raised to question my credibility than the credibility of what I have posted, but I'l answer anyway.
Yes, I hae considdered chamber position and shape, and as for position, it is quite simple to accomodate. For example if the chamber is set 2 mm to the rear, I simply run say 4 calculation sets, one with adding 2mm to the squish width for the front exhaust side, one with 2mm subtracted for the rear, and for the sides the width is just a little less than it would be if the chamber was centered, can calculate that or just measure it. Also if I want to get more detail for the squish velocty at any point arround the head, or for an asymetric chamber, the squish widths can be broken up into radial sections and a 2D squish velocity map made. Just take a little more time.
As far as gases being compressible, yes they are and I full well know that, however the context of wat I wrote was very specifically identified and only applies to modeling the gas velocity in the squish interface. Here is what I am getting at, do a little reading about finding gas velocity from pressure differential. When the piston moves up, the volumes of gas below the squish band and chamber are decreased by their respective areas multiplied by how much the piston rises. Key here is the volume of the gas in the squish band is porportionally much smaler than the volume in and below the chamber, and as the piston draws closer to TDC this is exagerated and there is a pressue differential created. This pressure differential can be used to calculate flow velocity and for velocities less than mach ~0.3, it can be assumed that a gas vill behave as a non-compressible liquid. I am sure Fred would have picked this info up in university physics also and can likely explain it as to why.
.Doug, you are right, we would only need to look at 10-20 degrees BTDC to fnd MSV, however, without looking at the trapping phase, compression and cylinder pressures cant be found, and simply put the tool I am working on was and is intended to do more than just look at squish velocity, running through 360 degrees allows loking at, base compression, profiled port time area or angle area numbers, piston acceleration, engne loads and a bunch of other stuff
I agree, it is often hard to follow MR's writtng, but i suspect this is more to do with an effort on his part to cloud the issues and interject ad honimen sidebars than it has to do wth his smarts or high state of education., or my lack of ability to understand issues. Funny Doug, you and MR are a lot a like when it cmes to these ad honimen sidebar attacks.
As for pumping efficiency, I am guessing you don't intend to say a 1 psi increase, most times this is a dimentinless number expressed as a percentage, You want to talk about that sure, but it has nothing to do with sqish calculatons or effects of squish velocity, nor does water injection or pipes other than what is the tolerated compression and desired squish dimentions based on RPM, fuel and the related detonaton issues. Yes squish angle affects squish velocity some and also the way the squish jets interact in the chamber, but also end gas must be considered, esp in motors with dimentions like a chainsaw motor. The effect of end gas alone can make sgnificant difference, there is some good readng on this.
I wouldn't want to miss anything.
