Hi BentOptics,
Thankyou for your reply. You have not put a downer on anything, you have actually just moved the project along substantially so everyone is thanking you
Ok so lets deal with the lubrication issue. Your right that in normal operation on traditional model RC fuels they mix oil in for lubrication. Obviously we cannot do this as our fuel is in an inert liquid state and the oil will be left behind when the liquid is converted into a gas fuel.
The potential solution that I see is using an oil reservoir from compressed air lines that they use for rotary tools in workshops. The rotary tool bearings need lubrication same as our engine does and they achieve this via the reservoir releasing small amounts of oil into the air as it passes under use.
A reservoir mounted on the carburetter intake would supply measured amounts of oil into the fuel mixture as it is sucked into the engine under vacuum. I think this would solve the problem with cheap off the shelf components.
I am puzzled why you refer to a piston seizure ? This is not a traditional ICE (Internal Combustion Engine) as we think of them, it has no pistons, the Wankel is a rotary engine with a single rotor. The bearings are the potential source of seizure in this design.
Here is a youtube video of the cutaway engine:
http://www.youtube.com/watch?v=eTbg92mRUG4&feature=relatedI agree with you that 17000 RPM operating speed is a potential problem and for what we are trying to do, undesirable. I will break down my thoughts on this into a few different sections:
17000 RPM has been built into this engine as it is designed for model airplanes running a propeller as the load. The propeller has to interact with a very thin fluid (air) and is the reason that high RPM is required.
Wind PMA's are designed to produce maximum power at very low speed, so they are the opposite of what we require for this project. This is the reason I suggested the 9:1 reduction pulley ratio. It will essentially convert the High RPM Low Torque of the engine into Low RPM High Torque for the PMA. Alternatively there may be some model RC reduction gearboxes knocking around at 9:1 ?
The other option is a custom PMA designed to produce the required Amp and Voltage ratings at 17000 RPM and could be mounted direct drive simplifying things somewhat.
This is the manufacturer of the AIXRO XR50:
http://www.woelfle-engineering.com/GB/mainframe.htmThe XR50 produces 33kW @ 8750 RPM with a 294cc chamber.
In development they have the XR20 which will produce 15kW + with a 160cc chamber.
So we are looking at around 10cc per kW output. This is awesome
If someone could convince either OS Engines the manufacturer of the mini Wankel or Woelfle that a 10cc Wankel with 10000RPM @ 1kW with maximum Torque was a good idea then they may sell a truckload of them
It is also interesting to note that Woelfle actually mention on the website that the Wankel rotary is capable of running on Hydrogen
So in summary, I agree with you that the lubrication of the engine is an issue but I believe the technology is there off the shelf to solve the problem. I also believe we can work with the 17000 RPM of the mini Wankel, an off the shelf component and make progress.
The numbers I have posted clearly show there is potential in pursuing these designs. These are the scientific establishments own numbers, not mine, so they would have to agree with the conclusions or violate their own principles.
With the off the shelf mini Wankel, a custom PMA and the power distribution model I have suggested for the Fuel Bank I believe a novice could pursue this route and really feel that they are getting somewhere without having a system so powerfull it scares them.
The Glowplug potential for ignition is particularly exciting to me as I have never previously considered this option. The alternative Spark Plug CDI ignition timing is plug and play and familiar to engineers in theory so should offer an interesting route to explore.
With the cost of prototyping this being relatively low and the ease and simplicity of the bolt together components it may offer curious people a real opportunity to get into this specialist area in a way that they are comfortable and make progress, learning as they go.
If we can get just 500W of power from the engine into the Fuel Bank then we have an unprecedented opportunity to create HHO in sufficient quantity, with known technology, to run a 5cc chamber at 17000 RPM. This to me is a very exciting possibility
Merry Christmas to you