Announcement

Collapse
No announcement yet.

Quasiturbine

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • Quasiturbine

    Hello,

    Mostly I lurk; picking up useful information at times for my home shop. Thanks to all that post for the information you have imparted.

    Have any of you heard about this engine called the Quasiturbine? Although it has been around since 1999 I stumbled onto it through this web site: www.howstuffworks.com and then www.quasiturbine.com. Is this the next "100 mpg" carburetor that gets shelved? In my searching I have found papers that seem to be sponsored by the by the design/inventor that tout all the wonderful things the engine does. And why would they not? It all sounds good. Almost to good.

    I have not been able to find any information about the downside or problems with the engine. Think about the applications and the simplicity of systems that require an engine if this engine is viable.

    Perhaps I could go back to working on my own vehicles with an engine this simple.

    By the way, I have no affiliations or ties with the Quasiturbine people. I am just a humble architect, marginal welder, and really bad machinist with an inquiring mind.

    If this has been discussed before my apologies. The search function turn up no results.

    Rob

  • #2
    "I have not been able to find any information about the downside or problems with the engine. Think about the applications and the simplicity of systems that require an engine if this engine is viable."

    Well, how about all those close fitting parts moving in hot gas? I recall seeing over the years dozens of very clever engine designs that failed to make it to market because of complexity, sealing, etc. These are not trivial problems to be glossed over with dismissive remarks but serious flaws that profoundly affect the cost of manfuiacture and the thermodynamic efficiency of the engine.

    The Wankel engine showed as much promise as any but only Mazda had the gumption to invest in it and bring a car designed for it to market. The car was the RX-7. Mazda spent hundreds of millions and never made a profit on the design. The car while reliable and a real performer had lackluster fuel economy.

    So it's not because of the Big Guys protecting their investments that necessariy causes new engine designs to be largely ignored but the practical questions like: Will it really work? Is it economical to manufacture? Will the public accept it? And, the big one: Can we make a profit on it?

    Comment


    • #3
      <font face="Verdana, Arial" size="2">Originally posted by Forrest Addy:
      Can we make a profit on it? </font>
      That sums it up perfectly

      Forty plus years and I still have ten toes, ten fingers and both eyes. I must be doing something right.

      Comment


      • #4
        Good points about the hot gasses and potential expansion of parts. Solvable problems? Who knows.

        In the limited info I have seen the only things powered by this engine are a chainsaw and a go-cart. Both of those use compressed air as the motivating force. I have yet to see a self sustaining engine powered by fossil fuels.

        This engine appears to be the next evolution of the wankle; solving the downfall of the poor fuel economy.

        Rob

        Comment


        • #5
          Forrest,

          I believe the first Mazda wankel sold in North America was the RX-2. I drove one in the early 70's. It was a little firebreather, weighing just around 2000 lbs with 130 hp. They had constant problems with tip seals on the rotors but were otherwise pretty reliable.
          Free software for calculating bolt circles and similar: Click Here

          Comment


          • #6
            If I remember right. The Wankle was originally intended as an air compressor for aircraft.
            And so far, from what I can see on their website, they have a four vane air compressor.

            Perhaps if they used ceramics for an internal combustion version.

            I wish them luck.

            Comment


            • #7

              The quasiturbine seems interesting, but I think it's a little silly to claim they can extract power without a crankshaft. Of course it has a crank, they just call it something else. An output shaft by any other name... Oh, I suppose you could use it to generate heat and extract that.

              I always thought the Wankel was a nifty engine, but I have also heard that:

              1. Apex seals are a bear to get right and reliable.

              2. Wankels generate a lot of heat.

              I always thought that one reason the Wankel is not as fuel efficient is that the power is extracted from a "glancing blow", rather than the "dead on" configuration of a piston engine. The quasiturbine works the same way, from what I can see. The quasi also has seals analogous to the Wankel's apex seals, but they have to move in and out a lot as the rotor spins. Are a Wankel's apex seals stationary with respect to the rotor? That would make them a little more simple.

              Another thing to consider is that, like a Wankel, the quasi is going to generate a lot of localized heat. The "hot" area is in the upper left of the engine as shown in the diagrams. Seems like that will be something that has to be addressed.

              One cool thing is that the Wankel and the quasi can run on a variety of fuels. This feature is one reason the US military has used Wankels for generators - they can burn most things you can pump.
              Finally, it looks like the quasi concept could be an interesting way to make a compressor, for either shop air or for refridgeration.
              The curse of having precise measuring tools is being able to actually see how imperfect everything is.

              Comment


              • #8
                The Wankel rotor seals are mounted in slots in the rotor apex and are held against the housing by centrifugal force as it spins. They are free to slide in and out.
                Free software for calculating bolt circles and similar: Click Here

                Comment


                • #9
                  Mazda wasn't the only one to sell Wankel engines in vehicles. I'm pretty sure that they bought the rights from NSU after their Wankel powered car didn't catch on too well. My brother had an RX-3 that we did a tranny swap on. He let me drive it after we finished it. That thing was FAST. Only problem was it badly needed a brake job. Didn't find that out until we were coming up to a blind, off camber corner going way too fast....

                  Sometime in the mid to late 70's Suzuki had a street bike with a Wankel in it - supposed to be the equivalent of a conventional 400-500cc engine.

                  Don't remember who made it, but someone had a "utility" engine (like a Briggs & Straton) too.

                  Tom
                  Tom

                  Be careful what you wish for, you might just get it!

                  Comment


                  • #10
                    The quasiturbine web site showed pictures of this engine mounted in a compact car but no video of the car moving under its own power.

                    What I found intriguing about the set up was that the shaft to an output device, i.e. generator, transmission, pump etc., could slide through the middle of the engine.

                    The site also talked about a propeller, possibly an impeller, being fitted to the center of the engine for whatever your imagination would want to do with that setup.

                    If more horsepower were required would a second or third engine assembly be fitted on a shaft.

                    Interesting concept for an alternative to the piston engine.

                    I think I will wait until the price comes down a little on the educational model before getting one to fool with.

                    Rob

                    Comment


                    • #11
                      Is there any evidence that one of the things has ever actually RUN as a combustion engine? All I could find, skimming the website, was a lot of, "This is how it would work if it did," but I might have missed it.
                      ----------
                      Try to make a living, not a killing. -- Utah Phillips
                      Don't believe everything you know. -- Bumper sticker
                      Everybody is ignorant, only on different subjects. -- Will Rogers
                      There are lots of people who mistake their imagination for their memory. - Josh Billings
                      Law of Logical Argument - Anything is possible if you don't know what you are talking about.
                      Don't own anything you have to feed or paint. - Hood River Blackie

                      Comment


                      • #12
                        Hey dont forget us Brits


                        http://homepage.ntlworld.com/derek.nicol/

                        all the best...mark

                        Comment


                        • #13
                          "1. Apex seals are a bear to get right and reliable.

                          2. Wankels generate a lot of heat.

                          I always thought that one reason the Wankel is not as fuel efficient is that the power is extracted from a "glancing blow", rather than the "dead on" configuration of a piston engine."

                          Actually the real reason for the lack of fuel efficiency are the two problems you mentioned. The Wankel does run hot (I believe because it vents the exhaust much later than a piston engine does), and the apex seals are somewhat fragile. Combine these two and you have an engine in which pre-detonation is both likely (because of the fragile heat) and very damaging (because of the apex seals).

                          The solution is to make the engine both run a little cooler and less likely to detonate by richening the fuel mixture (read-waste fuel).

                          Any difference in efficiency because of the "glancing blow" is made up for by the elimination of the huge amount of reciprocating mass inherent in the piston engine's design. Also efficiency is gained by holding the exhaust gases longer; piston engines vent them long before they're done expanding, wasting the energy that could be gained. Wankel engines hold them longer, and use that energy, albeit at a tradeoff of running hotter.

                          Disclaimer: This is my understanding, but I'm not an expert, so I'm sure something I said is wrong, or misstated somehow, hopefully someone will correct it though.

                          -Justin

                          [This message has been edited by jburstein (edited 10-13-2005).]

                          Comment


                          • #14
                            <font face="Verdana, Arial" size="2">Originally posted by aboard_epsilon:
                            Hey dont forget us Brits


                            http://homepage.ntlworld.com/derek.nicol/

                            all the best...mark
                            </font>
                            Now that's cool. Those things must be ridiculously fast. Well, most of them are racing bikes, after all.
                            The curse of having precise measuring tools is being able to actually see how imperfect everything is.

                            Comment


                            • #15
                              <font face="Verdana, Arial" size="2">Originally posted by jburstein:
                              Also efficiency is gained by holding the exhaust gases longer; piston engines vent them long before they're done expanding, wasting the energy that could be gained. Wankel engines hold them longer, and use that energy, albeit at a tradeoff of running hotter.</font>
                              I have to ask the obvious question, then. Has anyone investigated a way to retain the exhaust gasses longer in a piston engine? Or does that screw up everything else?
                              The curse of having precise measuring tools is being able to actually see how imperfect everything is.

                              Comment

                              Working...
                              X