PMD
Well-Known Member
click on the link, Stanislavz. It IS an opposed piston design - as was Prof. Junkers' fabulous 205 and 207, IMHO the best piston engines ever to fly.
The designer is an engineering prof. His consultant is a company that has been designing and building leMans winning engines and parts for the last 90 years.It's statements like these on new engine design websites that make me question if they even understand fundamental engine operation as they make a case for their advantages over existing designs.
Serviceability rates were low and they didn't become mainstream in front line fighter or bomber aircraft.click on the link, Stanislavz. It IS an opposed piston design - as was Prof. Junkers' fabulous 205 and 207, IMHO the best piston engines ever to fly.
Thus, why the statement "PCP is NOT generated at TDC".
click on the link, Stanislavz. It IS an opposed piston design - as was Prof. Junkers' fabulous 205 and 207, IMHO the best piston engines ever to fly.
yeah, I did miss it. Trying to catch a glimpse of the website while trying to get a few things done while we have the incredible weather (3 days left). Sorry for that. Problem might start with Dr. Fair being a fair bit British and using the language a bit differently from we colonials. I know what he meant as I converse with UK constantly.I think you missed the point of my post- you wouldn't want PCP developed at TDC in any piston engine. Have to have some crank pin angle to perform useful work.
Opposed piston, opposed crankshaft (OPOC) engines long ago "made it" starting from the earliest days of the last century (the first car to reach 100 MPH around 1902 (Gobron Brille), the justifiably famous Junkers 205 and 207 flying through the 30s into the 40s, many marine, rail and military versions, the iconic Commer knocker and continuing today in submarines (Fairbanks-Morse). They are making a strong comeback for some very good reasons (see many articles on Achates Power). Who knows - you might even see one in a little airplane one day soon.I like off beat, new engine designs and we have seen various types of opposed piston, rotary engines over the years but none have "made it". The theoretical gains are often quashed by the realities of making them work reliably and to be as durable as existing conventional engines with conventional crankshafts. The first company to prove they can do it all will probably find markets for their engines but have a mountain to overcome if they wish to push existing engines out of the big markets. Would take a couple decades if it ever happens.
Opposed piston, opposed crankshaft (OPOC) engines long ago "made it" starting from the earliest days of the last century (the first car to reach 100 MPH around 1902 (Gobron Brille), the justifiably famous Junkers 205 and 207 flying through the 30s into the 40s, many marine, rail and military versions, the iconic Commer knocker and continuing today in submarines (Fairbanks-Morse). They are making a strong comeback for some very good reasons (see many articles on Achates Power). Who knows - you might even see one in a little airplane one day soon.
Who knows - you might even see one in a little airplane one day soon.
Comparing three cylinder / six piston in inline 3 and delta :The layout has a lot going for it and with large engines the reason they were and are very useful is they can be considerably lighter for any given power - especially when going from one bank to three (Napier Deltic).
Well the website was last updated in 2015 and last I heard, this project was dead for now anyway. This one looked pretty cool actually and like it was going to be produced by Superior. The project dragged out for many years from the Westlake development and soaked up a lot of cash. The new Chinese owners of Superior don't seem too interested in engines for Experimentals, especially so after the triple debacles of their 382, 400 EXP engines and the latest crankshaft nightmare. These have devastated their reputation and probably cost them millions.Gemini :: Aviation
www.geminidiesel.aero
Deltics did not used master rods (would bugger up timing on other cylinder) but fork and blade type. Junkers was developing a 4 bank engine since they couldn't figure out how to do 3 bank. Napier did, and 3rd crank rotates opposite direction on Deltics.Comparing three cylinder / six piston in inline 3 and delta :
One extra pair of gears, and three single throw crankshafts in place of two with there throws + three master conrod + three articulated ones (due to 15degree difference between opposite piston, one piston transfer up to 70% of power) ?
And big pain in machining that three bores at 120degree each separation. In inline one - it is just much easier
Could you explain it in pm ?I am also a very amateur machinist and 60 degrees is pretty easy.
There is a school of design thought that still attempts to achieve these goals in high speed diesels - i.e. "rate shaping" the injection events. Again: one of those things the Otto cycle just can't accommodate.
For a given engine, a higher compression ratio doesn't mean there's more oxygen in the cylinder. The amount of O2 in the jug is set when the intake valve closes, before the compression really begins.Keep in mind that high compression itself doesn't really do anything .
It is the fact that more oxygen has been brought in to aid fuel burn.
It means the oxygen is more concentrated (smaller space)For a given engine, a higher compression ratio doesn't mean there's more oxygen in the cylinder. The amount of O2 in the jug is set when the intake valve closes, before the compression really begins.
Higher CR produces higher efficiency because it allows the same temperature to be achieved with less fuel, and because the expanding gasses do work over a longer distance.
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