Russian Rotary Engine (Plans)

[Evgen]

Hi! It Rotary engine developed by Russian designers
Sveticas and Melnik.It was used on a lung the helicopter in 1960. Has worked 80 hours. Dimensions
150x150x230 mm.Power of 30 h.p. Drawings in archive.
What you about it think?

[StephanWenger]

Hi,
the design looks like an elongated Wankel with a slightly off geometry :-)
Most Wankel engines have a rotor diameter to roter width ratio of roughly 2:1, because that yields roughly square combustion chambers. The geometry of the combustion chambers is the sore spot of the Wankel concept, and elongating it probably makes things worse, unless one is very careful with the geometry of the intake and exhaust ports, and uses multiple spark plugs. Also, the design of the seals is non-trivial when they need to be that long and need to work with those intake/exhaust ports...
If one's geometric requirements require such a long and small diameter rotary engine, the orthodox answer would be a multi rotor design (which, as a side effect, can also solve vibration problems in a very weight-efficient way--without counter-weights).
Finally, please note that modern (Mazda) Wankel engines place in/out ports on the front/back side of the engine, and not on the periphery. That would not work at all with elongated designs.
The design reminds me of low pressure high volume air/gas compressors. I vaguely recall having read that designs like this have been used (or were proposed) for pipeline pumps and the like.
Stephan