Engine - Related Dissertation topics.

[l354uge]

Hello all,

Heading towards the end of my placement year at an engine test facility, which means I will be picking my dissertation topic soon. Current ideas include:

• Using valve lift to control the 'throttle' instead of a standard throttle plate.
• Investigation into using solenoids instead of camshafts.
• Utilising thermal storage materials on the turbo and exhaust system to save thermal/electrical energy for the next engine start. (warmer engine at start up - less emissions and wear)
• Improving combustion chamber geometry to reduce unused air:fuel mixture. (reduce HC emissions and improve efficiency)

Thats all I have so far, if you guys have any input on my ideas or even some of your own that would be great.
I'd prefer something that could be proved with real-life testing, even though I haven't discussed anything with my employers/customers just yet.

[bmwmike]

I've always wondered, considering cam phases are 360° why a rotating hollow tube or tubes couldn't be used instead. Maybe look at that. Tube has cut outs for the "open" phase. It would need to be sealed against the ports somehow to maintain compression. Its potentially gives a much bigger valve area though I think.

[stevieturbo]

bmwmike said:

I've always wondered, considering cam phases are 360° why a rotating hollow tube or tubes couldn't be used instead. Maybe look at that. Tube has cut outs for the "open" phase. It would need to be sealed against the ports somehow to maintain compression. Its potentially gives a much bigger valve area though I think.

There are prototype engines out there that have done this, likewise BMW's Valvetronic already do the first item on the list.

Many things can and have been done....whether they truly offer any benefit, or cost benefit, reliability benefit....is another matter.

Plain old valves/springs undoubtedly arent the best option out there...but they work very well, are very cheap, and very reliable.

[l354uge]

Rotorcams (trademark pending...) sound like a very interesting idea!

I'm trying to find a balance between exploring something fresh (a high percentage of students will just do emission reduction through SCR/Cal changes) and something which has a fair bit of info available (friend did his on the current F1 hybrid engines, safe to say trying to get any data from the manufacturers was difficult).

I seem to have my heart set on the camless engine idea, it certainly makes more sense than having camshafts with vvt, vvl, vde and other goodies bolted on! lets hope Koenigsegg reply to my email...

[DVandrews]

Lanchester tried using solenoids for valve actuation in the early 1900s, but these proved too slow in response. Maybe today's technology can improve the response times.

Dave

[bmwmike]

stevieturbo said:

bmwmike said:

I've always wondered, considering cam phases are 360° why a rotating hollow tube or tubes couldn't be used instead. Maybe look at that. Tube has cut outs for the "open" phase. It would need to be sealed against the ports somehow to maintain compression. Its potentially gives a much bigger valve area though I think.

There are prototype engines out there that have done this, likewise BMW's Valvetronic already do the first item on the list.

Many things can and have been done....whether they truly offer any benefit, or cost benefit, reliability benefit....is another matter.

Plain old valves/springs undoubtedly arent the best option out there...but they work very well, are very cheap, and very reliable.

I don't mean as a hollow camshaft but a rotating tube which itself has the ports cut into it. A single moving part could replace camshaft and all associated valves, springs etc.

[tumble dryer]

bmwmike said:

stevieturbo said:

bmwmike said:

I've always wondered, considering cam phases are 360° why a rotating hollow tube or tubes couldn't be used instead. Maybe look at that. Tube has cut outs for the "open" phase. It would need to be sealed against the ports somehow to maintain compression. Its potentially gives a much bigger valve area though I think.

There are prototype engines out there that have done this, likewise BMW's Valvetronic already do the first item on the list.

Many things can and have been done....whether they truly offer any benefit, or cost benefit, reliability benefit....is another matter.

Plain old valves/springs undoubtedly arent the best option out there...but they work very well, are very cheap, and very reliable.

I don't mean as a hollow camshaft but a rotating tube which itself has the ports cut into it. A single moving part could replace camshaft and all associated valves, springs etc.

I'm not quite getting this, where does the tube sit?

[bmwmike]

tumble dryer said:

I'm not quite getting this, where does the tube sit?

Excuse the awful drawing i did it on my phone. The tubes sit across the cylinders pretty much where the camshafts would go. Instead of cams they have holes in them which line up with ports on the cylinder head. When the port on the head and the port on the tube are overlapping the valve is open.

[stevesingo]

By way of an improvement, why not have the tube slide upon it's axis where you can have a change of cross section of tube orifice exposed to the port at different axial displacement. This could the throttle the engine also.

With an elliptical orifice shape port open duration could also be varied.

[bmwmike]

stevesingo said:

By way of an improvement, why not have the tube slide upon it's axis where you can have a change of cross section of tube orifice exposed to the port at different axial displacement. This could the throttle the engine also.

With an elliptical orifice shape port open duration could also be varied.

Totally.. not sure about sliding because as it stands its easily driven by a chain or existing cam phasing / timing. But I agree you could get creative on the shape of the opening... curved, trailing, etc. Basically drawing the lift onto a 2d surface.

[E-bmw]

bmwmike said:

Excuse the awful drawing i did it on my phone. The tubes sit across the cylinders pretty much where the camshafts would go. Instead of cams they have holes in them which line up with ports on the cylinder head. When the port on the head and the port on the tube are overlapping the valve is open.

Sounds like an adaptation of a 2 stroke engine, not sure if it is a positive as I am no expert. Surely the "ports" would be the restriction to flow, whether it is a positive step, I have no idea.

[stevieturbo]

bmwmike said:

I don't mean as a hollow camshaft but a rotating tube which itself has the ports cut into it. A single moving part could replace camshaft and all associated valves, springs etc.

yes, it's been done before, the issues are usually getting it all to seal whilst allowing the rotation.

https://www.youtube.com/watch?v=XUHugGIv6AE

https://www.youtube.com/watch?v=vjHkAgi9TbY

https://www.youtube.com/watch?v=pDsRa4eT7co

[bmwmike]

Could well be.. I am certainly no expert neither lol. Just offering up ideas for the OP'S project.

I guess the spinning tube could act as a fan too which might be counterproductive depending on which way it blows lol

[bmwmike]

stevieturbo said:

yes, it's been done before, the issues are usually getting it all to seal whilst allowing the rotation.

https://www.youtube.com/watch?v=XUHugGIv6AE

https://www.youtube.com/watch?v=vjHkAgi9TbY

https://www.youtube.com/watch?v=pDsRa4eT7co

Cool ! Thanks for those.. the last one was ace

[Markbarry1977]

bmwmike said:

I've always wondered, considering cam phases are 360° why a rotating hollow tube or tubes couldn't be used instead. Maybe look at that. Tube has cut outs for the "open" phase. It would need to be sealed against the ports somehow to maintain compression. Its potentially gives a much bigger valve area though I think.

Already tried years ago by ford for one look up spherical valve engine.