RotoMax Rotary Engine... Tesla - Wankel - Mason HHO Hybrid

[evolvingape]

Hello Everyone,

This is the RotoMax Rotary Engine prototype design. It is a Tesla â€" Wankel â€" Mason HHO Hybrid.

Completion of the HHO PCT project a few weeks ago allowed me the time to finally get to work on developing the vague concept that I had in mind when I designed the Linear Firing Valve. It has now fully matured, faster than anticipated, and I present it to you. Enjoy

Let us begin at the beginning...

The LFV was designed to solve a number of problems with utilising HHO as a fuel.

I first removed the combustion chamber from the engine. Hydrogen experiences automatic ignition at temperatures of 500 degrees C and above. This problem is made worse because HHO is in a gaseous state and must be compressed in order to charge the chamber, this further decreases the auto ignition temperature, especially with a compressed oxidiser also present.

By removing the combustion chamber to the outside of the engine casing we are able to water cool it separately and also reclaim some energy as discussed in the HHO PCT thread, energy which I intend to be used to fire the Buzz Coil Ignition System.

I was also able to incorporate the Energy Conversion Insert into the design which changed the process output from high heat and compression to lower heat and velocity.

By applying this velocity to a Tesla Boundary Layer Turbine we can effectively use this energy.

The Tesla Boundary Layer Turbine suffers from a few problems. It is highly dependant on a very large disc surface area to fully maximise the transference of energy from the supersonic fluid to the disc surface through the Boundary Layer Effect.

Tesla knew this and was the primary reason his turbines became progressively larger in size until he reached 60 inches! The problem with going large diameter is that the turbine must be spun slower because the disc material experiences far greater forces at the tip than the centre due to the speed differential creating massive shear forces within the disc material itself, causing it to critically fail.

The other problem with the Tesla Turbine is that it is a hot rotor and as such has no seals. This causes valuable pressure to be lost between the disc stack and housing inner wall, effecting efficiency in a negative way. We try and limit this pressure loss by having close tolerance clearance but there is always going to be a gap, which is typically about 1mm or 0.040”.

So the Tesla Turbine is not sufficient on its own to utilise the high velocity fluid the LFV is producing. This is where we examine the Wankel Rotary Engine.

The Wankel is a fantastic design but also suffers from some problems in light of what we are trying to do. It is relatively complicated to build requiring exacting tolerances and precision gear ratios. It also has the combustion chamber inside the engine which may present a problem with automatic ignition.

It does however have only a single rotor and produces bags of Torque with a smooth torque curve all the way to maximum RPM, which is about 10,000 RPM, half of a Tesla Turbines 20,000 RPM.

The Wankel also has a wonderful rotor edge to casing seal in the form of a spring loaded gate!

So now lets examine the RotoMax and see why it is different...

The output from the LFV and the input to the RotoMax chamber is high velocity fluid. In order to utilise this energy effectively I have reversed the function of the ECV and converted the high velocity fluid back to compression pressure.

Due to the potential difference created via linear distance from the pivot centre to the area of maximum compression in the compression chamber a high torque rotational moment occurs.

Following the compression phase the fluid experiences expansion maximising the energy potential remaining and then experiences parallel flow into the Tesla Boundary Layer Stabilisation area.

After spiralling around it comes into contact with the Winglets arranged at a suitable angle and generates lift forces which also create a turning moment increasing efficiency by stripping more energy from the fluid.

The aim of the game being to balance the system so that all of the velocity is removed from the fluid by the time it exits the exhaust parallel to the shaft.

As we have once again gone full circle and are dealing with a compression rotor sealing becomes extremely important. This is why I have adopted the Wankel approach with a spring loaded gate seal between the rotors edge and the inner ring casing wall.

This solves the problem of rotor tip sealing but leaves us with a problem sealing the disc face to the housing wall. To solve this I have used a static spring loaded ring that pushes against the face of the spinning rotor.

You can see there are two compression chambers formed by two gate seals located 180 degrees from each other.

As the rotor spins the LFV is phase angle fired as the first gate seal passes the LFV parallel flow tube. The LFV must have completely finished its firing cycle by the time the second gate seal at the back of the chamber passes the LFV. With the speed of the hydrogen combustion reaction this should not be a problem as the LFV chamber size will be tuned to the compression chamber size and desired operating rotational speed.

The Energy Conversion Winglets are critical to the design, they come in pairs, and work together to create the compression, expansion and parallel flow stabilisation as well as creating the dimensions of the compression chamber itself.

I have omitted the rotor compression and hub mount bolts for clarity. You will have to decide how many you need and where to place them.

The entire rotor is made with two side discs and shaped spacers that form the RotoMax chamber in exactly the same way as a Tesla Turbine is constructed. I recommend we go with a chamber width between the discs of 0.75mm or 0.030” to use 50% crossed boundary layers for maximum efficiency. This is because we are dealing with a high velocity and low mass flow rate fluid.

Each RotoMax Rotor is a separate unit and multiple units can be mounted on the same shaft, providing increased power and more flexible firing and charging ratio options.

If you place more than one RotoMax Rotor inside the same housing you will lose efficiency due to an inability to seal the inter rotor gap causing pressure to bleed from one rotor into the other.

You can try a prototype in 316 and have it up and running in days, especially if you already have a few LFV's built and functional. If excessive operating temperature becomes a problem and 316 cannot handle it then there is another option.

Ceramic Carbon Brake discs (or the variant called Carbon â€" Carbon). These were pioneered in Formula 1 racing and are now commonly found on high end sports cars. The disc shape is already an established manufacturing process so no problem there. The spacers will require new mould techniques maybe and a bit of R & D.

Ceramic Carbon is a good choice because it has a very high operating temperature, is very hard, creates little dust and is much lighter than steel. Its almost like it was developed for this engine!

I know the RotoMax diagram looks like a four year old drew it, but I never was very good at drawing.

Here are some links for further reading;

Here you can see the Wankel gate seals:

http://www.youtube.com/watch?v=eTbg92mRUG4&feature=related

Here is some information on Ceramic Carbon:

http://www.systemst.com/technical-information/

http://en.wikipedia.org/wiki/Disc_brake

http://en.wikipedia.org/wiki/Reinforced_carbon-carbon

I will have a look later after some sleep and see if I missed anything out.

Have fun

RM

[evolvingape]

Hello Everyone,

Here is the original RotoMax concept with a single Energy Conversion Winglet. I wanted to get the dual ECW version out of the way first while it was fresh in my mind.

The RotoMax is designed to run on any fluid, so lets talk about those possibilities first:

To run on HHO the chamber spacing must be 0.75mm or 0.040” as already discussed. This is because HHO combustion produces a high velocity, low mass flow rate fluid. The parallel flow input tube must have the same bore diameter as the chamber.

The engine will also run on low pressure air with high mass flow rate or pulses of high pressure compressed air (800 â€" 3000 psi), which is a high velocity, low mass flow rate fluid. More on this later.

The engine will also run on pulses of high pressure water with either a high pressure, low mass flow rate or low pressure, high mass flow rate.

If we were to change the chamber spacing to say 5.4mm for example the engine will now be suitable to run on low pressure, high mass flow rate fluids. The reason I say 5.4mm is that this is the bore diameter of 1/8” Schedule 80 pipe, making it simple to mount an off the shelf parallel flow tube. 6mm will be an acceptable compromise utilising ECW spacers cut from 6mm 316 sheet.

I have also updated the RotoMax Section View with a more accurate schematic. This now shows the shaft, hub and mounting bolts as well as the rotor compression bolts that lock the ECW in position.

Note that I changed the design slightly to remove the ring spacer compression spring, this will simplify construction and instead relies on a very close tolerance the same as the Wankel Rotary does. This will still leave a slight gap for pressure to bleed through but will be an improvement over no seal at all. You can try both designs if you want to find the most efficient.

Now, lets talk about high pressure air and water pulsing prototyping...

I have provided a cut-away view of the K valve (¼ NPT threads) that is used in the cleaning industry for high pressure wands. This will act as the pulse trigger for either high pressure water or high pressure air.

Here is the manufacturer:

http://www.westpakusa.com/Page150/Control_Valve.aspx

And here is one of the ebay retailers you can buy it from:

http://cgi.ebay.com/K-Valve-Handle-Stainless-wands-carpet-2000-PSI-/200457562946?pt=LH_DefaultDomain_0&hash=item2eac33ab42

We must construct a voice coil firing trigger that will be timed via either an opto-interruptor or a reed switch using a timing disc. This will momentarily activate the coil, attracting the magnet, which will hit the K valve piston and open it.

The K Valve piston will slam open allowing the high pressure fluid to flow. When the circuit is closed, the coils magnetic field will collapse and the magnet will be pushed back by the spring, allowing the spring in the K valve to close, shutting off the flow.

If you were to use a paintball high pressure tank rated at 3000 psi then you would have the ability to pulse high pressure air at either the 800 psi output from the regulator or remove the compression spring or belleville washers and run the output unregulated at 3000 psi. You can also add belleville washers or a new compression spring and change the regulator output pressure to a new value.

As always BE CAREFULL!

If you were to run timed tests ie 30 seconds for example then you would be able to compare the properties of the RotoMax chamber with different variables of the ECW spacers.

Low pressure fluids at say 100 â€" 120 psi from a compressor or jet washer can just be run constant with 100% duty cycle as you will need a very high mass flow rate at low pressure.

The area of maximum compression in the RotoMax chamber will set the variable for how fast the fluid will pass through the ECW into the expansion and parallel regions, so change the gap, change the performance of the rotor.

There are so many possibilities for this new type of engine that I have tried to cover the operating principles and a basic outline of what you need to test for and how you can go about doing that.

Get creative

Here are some resources:

Drill blanks:

http://www.drill-service.co.uk/Product.asp?Parent=020620040000&Tool=363

Note: Drill blanks always come in under size, if you order a 5.4mm you will get a 5.37mm.

Ring Magnets:

https://www.hkcm.de/advanced_search_result.php?keywords=ring&prof=off&hkcm=engineering&dna=2&mwst=on&des=

Note: You want an axially magnetised ring not a diametric. Loctite them on permanent.

RM

[evolvingape]

Hello Everyone,

Here is the RotoMax 12 LFV. It combines into one turbine the principles of impulse, reaction and boundary layers.

I have not written on the drawing the information as I am sure you have all grasped the principles of operation by now. By using 12 ECW's I have removed the balance issues with the rotor.

This is the final version and is designed to be used with 12 Linear Firing Valves with one valve located every 30 degrees around the rotor casing.

This allows us the flexibility of priming / firing ratios as discussed in the HHO PCT thread.

We can see that each valve will have its own compression chamber, creating an equal and opposite reaction, causing an impulse rotary moment around the pivot magnified by the potential difference.

The fluid will then experience parallel flow around a curve (I have drawn straight lines as curves were simply to difficult to accurately draw freehand). The inter disc spacing is set at 0.75mm or 0.030” causing 50% crossed boundary layers. The inter vane gap is also set at 0.75mm or 0.030” causing another 50% crossed boundary layers 90 degrees out of phase from the original.

This will create a central region of 0.25mm or 0.010” where 4 boundary layers are experiencing crossover creating a much larger effect.

Each vane will work with the one either side to create the parallel curved channels that will spiral around 180 degrees and directly feed the leading edge of their own lift winglets.

Each compression chamber is sealed from the next via spring loaded gate seals as already discussed.

So, four rotors mounted on the same shaft will become a 48 Valve system with pulsed detonation phase angle timing.

Have Fun

RM

[ramset]

RM
WOW!
I have watched the Vids you posted[Linked to]also above ,
Unfortunately my computor doesn't get sound.

I believe a design for HHo will be very important in the near future,And you have most definately given this serious attention!
At what kind of efficiency do you feel these concepts are at right now?Or ultimately capable of?
Thanks
Chet

[evolvingape]

Hi Chet,

Don't worry about no sound, you did not miss anything, there was nothing to hear

That is a very difficult question for me to answer but I will try...

I have always had the ability to build machines in my mind, I can set the operating parameters and run it and also change the variables within the system on the fly, by understanding the relationships in the environment, and calculating the outputs.

So, if your asking me how “finished” do I think the RotoMax is ? Well...

Erm... about 90%

The remaining 10% has to do with two concerns I have that I have not mentioned.

The first is the disc side face to housing side plate seal. Being a compression engine primarily we can get away with a very close tolerance as the Wankel Rotary does but I will never be happy with any pressure loss, as it is a loss of energy. This is the reason for the side ring seal.

The issue with the side ring seal is:

Will the resulting friction on the disc, causing drag, be worth the wear to the disc and the increased load ? Or will the pressure retained within the rotor more than compensate for it ?

Unknown at present to me.

The second issue concerns the Linear Firing Valve. Will the coefficient of thermal expansion of the material be at a suitable limit to prevent the semi mechanical seal of the piston poppet expanding to a diameter that causes it to jam in its sleeve ?

This will not be a safety concern as the pressure wave from detonation will be so powerful the valve will slam shut no matter what (unless foreign objects obstruct), but the spring pressure may not be enough to open the valve again. This is a materials issue and not a theoretical issue, as I believe the theory is sound.

The ideal scenario would be that when the LFV chamber is up to operating temperature the chamber wall and the piston poppet will be at maximum expansion and create the close tolerance seal. As I do not know what the operating temperature will be I cannot calculate the clearance required for the components at room temperature. So my best guess was 10 microns maximum, if it jams you need a larger clearance

The other alternative being that once you know the expansion variables you warm the chamber and poppet to operating temperature before you turn the machine on, using a glow plug.

When it comes to the aerodynamic properties of the rotor inter disc gap itself I consider it to be complete. In my opinion I can not improve on the design I have presented. 12 compression chambers being at the limit of what it will be practicable to build leaving suitable material thickness and spacing for the ECW's and Vanes. It also balances the rotor very well

I designed the RotoMax to outperform all known turbines and rotary engines. I am hesitant to state that it will because I just do not know the answer yet until it is built and tested, but I “expect” its power to weight ratio to exceed any engine known today.

I also designed it to be incredibly cheap and easy to construct. Not a problem for running it on air or water as 316 is more than suitable, but there is a ? over 316 for HHO, which is why I have also offered carbon â€" ceramic as a potential solution.

There is another material that may be even better and that is ceramic matrix composite:

http://en.wikipedia.org/wiki/Ceramic_Matrix_Composite

However this is still cutting edge and extremely expensive. Scroogle search there is lots of information out there on it.

So lets talk about my choice of layout for the different functions of the design...

As already discussed the Tesla Turbine operates on the boundary layer principle, but suffers from the problem of extracting the torque from the fluid in a short time component, requiring large discs.

Its impossible to get around this due to the nature of the boundary layer effect itself, so in order to maximise the torque extraction I have doubled the surface area for the fluid to interact with by enclosing the fluid in a square box. This will have benefits in crossed boundary layers and 90 degree out of phase crossed boundary layers, which are as of this moment an unknown potential.

The other benefit is that the box can now be used as a guide for injecting fluid at the correct angle of attack for the Winglet aerofoil section.

The Winglets do not function primarily by extracting torque from the fluid via the boundary layer effect. The boundary layer effect serves as the medium of interaction between the surface of the Winglet and the fluid.

The Winglets generate lift via creating a pressure differential between the upper and lower surfaces. The amount of force generated is directly related to the angle of attack, the properties of the curves of the aerofoil section, the velocity of the fluid, and the distance the Winglet is from the pivot.

By moving the Winglet close to the exhaust, rather than at the outer edge of the disc we are losing force potential due to a smaller linear distance between the Winglet and the pivot but we are not losing (much) force due to reduced fluid velocity over the Winglet. This is because the ECW inlet lets “some” velocity through the small gap relatively untouched, this is at the very beginning of the detonation pulse and can be considered the leading edge of the pressure wave.

The other point is that the Winglets also have an upper limit of fluid velocity that they can utilise. Velocity exceeding this value has no added lift effect. The Winglets also only need the boundary layer to operate, any fluid further away than that is ignored.

The area of maximum compression is where the majority of the energy is extracted by creating a partial blockage. By placing this Impulse at the furthest point from the pivot maximum rotary moment is generated far exceeding what would be possible from a Winglet, because the limiting factor on the compression phase conversion is the velocity of the fluid. The larger the input velocity to the compression phase the larger the Impulse created.

So in summary, we could swap the different functions around, but I do not see an increased benefit in doing so for the reasons stated.

As for the potential of this engine... well... how about this...

A huge field of solar panels in the desert, running massive dry cell HHO generators that run the LFV's, that power the RotoMax engines, to generate electricity to pump seawater and distil it, to turn the deserts green.

I like that idea very much

RM