Quasiturbine engine takes in fuel after compression

  • Thread starter sid_galt
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Main Question or Discussion Point

If the quasiturbine engine takes in fuel after compression and then burns it at constant volume, wouldn't that increase the efficiency of the process as constant volume burning is more efficient than constant pressure burning at same compression ratios?

If such a burning is not possible, what are the reasons?


edit: one more question

Why are the quasiturbines not busting into the market because from the descriptions I read on the net, they offer huge advantages over other engine types.

What about rotary vane engines. What is their status?
 
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Answers and Replies

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sid_galt said:
Why are the quasiturbines not busting into the market because from the descriptions I read on the net, they offer huge advantages over other engine types.
Well, does anyone have any comments?
 
Danger
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sid_galt said:
Well, does anyone have any comments?
Patience, lad. I need some time to look it up; I never heard of a quasiturbine until you posted this.
 
501
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I guess I should have provided some links

Here is the homepage of the quasiturbine
http://quasiturbine.promci.qc.ca/

Here is the patent application with diagrams
http://quasiturbine.promci.qc.ca/QTAppl.html

They say that the quasiturbine has the potential to run on detonation mode.

At any rate one disadvantage I see is that the rotor will be very heavy to withstand the stress and will make throttling more difficult. Plus the flexible seal on top of the carriages will need to be very strong to withstand the shear stress. Same goes for the carriages. Plus the carriage wheels will generate a lot of friction with the casing.
 
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Q_Goest
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Just thinking out loud here, but I wonder how they intend to seal the sides and rollers in that engine. The same problems hold for vane type motors.

For a recip engine, the combustion chamber is nicely sealed with piston rings. For this quasiturbine, there is no real sealing mechanism - the seal is accomplished by minimizing the gap which must change due to thermal gradients in the engine. A vane type has less of an issue, but it still is an issue. At least for a vane type, you have a sliding seal on the circumference, but you still only have a close fit on the sides. Any gas passing through that gap represents a loss in efficiency.
 
501
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The wiki article says that leakage problems encountered in the quasiturbine are similar to those encountered in early Wankel Engines but they have been brought under control.

Here is the howstuffworks article.

The official website claims that since the volume of the gas increases during combustion, during detonation the pressure peak is for a very short amount of time making this much more detonation compatible than the piston engine.
 
FredGarvin
Science Advisor
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I must admit that this is the first I have read about these. They are interesting. The first thing that came to my mind is the complexity of the rotating components. The basic diagrams don't show too much but I would be worried about centrifugals on the "rotor" assembly. I'd also like to see how they actually attach a shaft to that rotor assembly. I haven't finished reading the entire site yet though.
 
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I would imagine the shaft will be directly attached to the rotor assembly though it would be very heavy to withstand the stress and would like generate good friction.

Quasiturbines can even demonstrate near-continuous combustion delivering constant power.
 
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sid_galt said:
If the quasiturbine engine takes in fuel after compression and then burns it at constant volume, wouldn't that increase the efficiency of the process as constant volume burning is more efficient than constant pressure burning at same compression ratios?
I don't know about quasi turbines but I know that regular turbines create a constant pressure (actually a slight pressure drop) in their combustion chambers in order to maintain a favorable pressure gradient for the flow.
 
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Well, what do you guys think of this? Is it worthy? One thing I was wondering about was in large quasiturbines there would be a substantial energy loss in trying to constantly rotate the carriages.
 
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Dagnabit. Now I am interested. Has anyone found any new info on this type of engine? I just recently stumbled on the howstufworks.com article and now I am interested in what some of the posters around here would say about it.
 

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