A Doctoral Thesis on two stroke engines

As very much a non-engineer, I have always being interested in the workings of most things mechanical even if I don't quite understand the theory. Happened to come across the contents of the link which others of my ilk who dip into this forum may find informative.

All those well versed in the tuning of such engines should find other more useful things to do!

To avoid excessive mental excitement I suggest you start from chapter 6, page 133.

Jim

https://dspace.lboro.ac.uk/dspace-jspui/bitstream/2134/14808/4/Thesis-2013-Lewis.pdf

Nice one Jimmie... worth a read

I agree with Nigel but I am only part way through the explanation of symbols so far, after -- having read the INTRODUCTION: .

The latter suggested that what the Bantam Club members have done over half a century  is all in there along with some fresh ideas like having DIRECT Injection of fuel and a couple of other aspects concerning Reynolds number that Trevor mentioned on here recently. I was a bit bewildered about the use use of words by the contributors.  We could look at "Quasi" for a start. In my Oxford Dictionary  it says "Seemingly", "Not really" and "Almost" which suggests the author will become a "Doctor" of engineering for having done a lot of research without actually having done anything really practical, like sitting by a dyno for hours and hours or having had a young blood rush about race curcuits Testing Specials for him...
  Getting titles  is something the Germans here just love in their auto or other technical companies to show how brilliant their company is ...

    I shall no doubt get shot down by what I said there. To promote their Intelligensia PICTURE TO THE PUBLIC some universities and a lot of motor compANIES -- particularly Ford, I worked for -- for a time -- take a clever lad on the staff and give him (and maybe a buddy)  a subject to work on that appears to have been neglected or ignored or actually dumped:---  
---like the German "Salad Oil" engine or the British*** "Sterling External Combustion" engine and give him (or them) several months off -- from entering the Works premises -- to do research and produce something that suggests can be done or would be done if it got financial backing.
... The Salad Oil engine was so called because the German Father & Son team made an engine with a two part  piston  (variable comp... ratio) controlled by two injection pumps which they drove through Germany into Austria. Obviously for publicity purposes they  stopped in a town at several  restaurants  ordering as much salad oil -- or other edible oil the restaurant could stand parting with at one time -- saying each time they  had run out of fuel. In the early Eighties that made a big splash, in the papers and on Telly -- because fuel consumption had become a high Priority.
   I was in  Burundi, West  Africa, in the Eighties -- when a Colonel from the Burundi army approached me to explain how this engine worked and asked how their gióvernment could get a hold of the patent to make the engine in mass production. I had to plead lack of time to explain and rapidly got on the blower, back at my hotel,  to my German  engineering buddies to get the explanation so I could go back next day and tell him ....
Thing was it came to nothing because an engine company bought the patent and killed it dead -- as they did With the developed Sterling -- at about the ´same time -- a paper by an English engineer caused a stir and then there was the variable length con-rod engine varying the compression-ratio by our famous  two-stroke, EMC,  Doctor Joe Erlich at De Haviland whose variable CR engine  was bought -- it seems  -- by GM for the same purpose of making sure no other company could make a success of the idea...

*** Sterling -- or Sturling -- was a Scottish Parson who invented this engine which could be a winner if its sealing problems were solved -- so it was said  ....

   I shall now read the paper and maybe find out I have been too quick in criticising, because any research should be applauded for what it is...  but I feel very strongly about awards of ´such Doctorships to young enterprisers who have never actually got their feet wet with experience as many of our brilliant BRC two-stroke tuners have. I won`t say they are vultures -- too nasty -- picking on the bones of other people's hard work but they get recognition which the likes of our Bantan Racer tuners never got....

A lot of enthuiasts -- as we have had, and still have in the BRC -- have done far more practical, worthwhile development work than many Doctors and highly titled Fellows I know and have had to work with.

   So now -- to read and find out:

Cheers!

JayBee (preapring for the brickbats...).  




r

I go along with you Nigel it is an interesting read.

I am only a little way into it...

Being pragmatic I tend to shy away from Computer Modelling to do development work and am a great believer in the practicality of combustion chamber shape being important to such engine development being discussed here.

Direct Injection diesel engines have the combustion chamber in the piston crown where Indirect Injection forms  have the Bowl ( as in the Comet Precpombustion Chamber)  being connected to the cylinder by a channel called the Throat.

I haven't come to it yet, in this paper, that  the chamber shape is taken too seriously and saw that a "Disc chameber"  is compared with a typical Top-Hat version with a swish band similar the latest Bantam's... . Because of the obvious difficulties with Disc edges   I'd thought such a Disc chamber would not have even been considered.
I must read more of it .., since the Disc being only computerised might be more significant than I thought although still in the back of my mind is that a different chamber shape might have been better to make combustion performance comparisons.....
......  

Where has Trevor got to? I thought we'd be hearing from him by now.

Cheers!

John.