Loading ...
Sorry, an error occurred while loading the content.

Re: [Small4-strokeEngines] electric generator

Expand Messages
  • mrk@karenfuxia.com
    Hi Tom   thank you very much for your link. their technology looks modern though a little dated (publications are from 1994-5 years). moreover their generator
    Message 1 of 12 , Sep 1, 2011
    • 0 Attachment
      Hi Tom
       
      thank you very much for your link. their technology looks modern though a little dated (publications are from 1994-5 years). moreover their generator goes through spinning stuff.... extra hardware and weight (in first approximation of course) thinking airborne... maybe just putting a prop on their wobbling plate would go :-). good as a reference in any casemrk
       
       
      From: Small4-strokeEngines@yahoogroups.com
      To: Small4-strokeEngines@yahoogroups.com
      Cc:
      Date: Wed, 31 Aug 2011 06:42:29 -0700 (PDT)
      Subject: Re: [Small4-strokeEngines] electric generator


      <!--
      -->


















       









      If you are interested in sterling-and generators here is a link that may be of interest
      http://www.whispergen.com/main/technology/
      Tom Steedman

      --- On Wed, 8/31/11, mrk@... <mrk@...> wrote:

      From: mrk@... <mrk@...>
      Subject: [Small4-strokeEngines] electric generator
      To: Small4-strokeEngines@yahoogroups.com
      Date: Wednesday, August 31, 2011, 8:32 AM

       

      hello everyone
       
      it's me again with odd questions"waiting for good energy density batteries" (zinc-air?) i believe that keeping the end part of the propulsive chain in electric (=the motor ;-) it could be viable making a hybrid vehicle that has a combustion-something producing electric energy and then feeding this to the motor. electric motors run on a 90% electric efficiency, just recalling this.they do this hybrid stuff already in prototype/projects.... somehow use fuel cells or turbine electric generator.... all stuff for the big pockets.
       
      don't need a full-power electric generator. just to sustain economic cruise speed... the long part of the trip. will use some batteries for extra power during takeoff, go around, climb... electric motor weight is not a problem (i recall, current brushless motors surf around 4 kW/kg (power out/motor weight))by the way, if any of you is thinking on solar cells, at current efficiencies (~20%) you can fly at about 50-70 km/h at ultra-best (i have quite a good deal of computations, if anyone is interested), with a very (ultra) clean design and of course midday sun. solar cells can yes be used for recharging your batteries, as you are not flying. it takes a while, though. it all depends on how you cut the cake (type of flight, intended use, etc.)off-the-shelf piston electric generator do weigh. one can get rid of all the fancies they use (the frame, wheels, etc) but they will still weigh, even if one thinks on eco cruise power to be put out. anyone knows of a
      good one, by the way? say around the 6-8 kW figure to start with.
       
      sometime ago i wrote about stirling free piston engines (or did i dream to write about it?) used as electric generators. they do this on solar plants (mirror concentrators). "just" an oscillating piston, a coil and magnet.... and voilà, the AC current is out. seems interesting, on a weight perspective too. imagine, no crankshaft, no valves, no nothing. "just" a piston going up and down, a magnet attached to it, and a coil around the magnet. somehow hey, worth a thought!
       
      the stirling cycle is external combustion. just make heat somehow, then "plug" the hot part of the engine into the heat source and it will work. seems interesting, on alternate fuel perspective too.so, to resume
      anyone knowing of a good electric generator?anyone with directions to alternative electric generator fashions, for small pockets?
       
      mrk

      [Non-text portions of this message have been removed]

      [Non-text portions of this message have been removed]


























      [Non-text portions of this message have been removed]
    • mrk@karenfuxia.com
      from some google search  nasa mti 25 kw stirling engine i found documents like this one
      Message 2 of 12 , Sep 1, 2011
      • 0 Attachment
        from some google search  "nasa mti 25 kw stirling engine" i found documents like this one
        http://sri.auburn.edu/papers/2007/5_kw_stirling_demonstration_iac_07_c_3_2_07.pdf
         
        those are stirling free pistons (usually in opposite config to -seemengly- not need additional damping-tuning masses...) coupled to linear alternator.
        they speak of 6 kg/kW for their generator with an overall efficiency of about 25% (electric energy out/energy in), intended to be used on the moon (!). this is 0.166 kW/kg.... still very heavy to be airborneanyhow, i should have more technical knowledge to understand in what their design "suffers" from the moon use (heating method, reliability factors, etc) in order to make it more light. looking at some pictures, it seems they did not make economy on bolts and other heavy hardware that.... might be rethinked. looks nice though.... very space age, with a taste from the sci-fi beta movies from the '30s :-)anyhow up to now, that's the best stuff i have found
         
        mrk
         
         
         
        From: Small4-strokeEngines@yahoogroups.com
        To: Small4-strokeEngines@yahoogroups.com
        Cc:
        Date: Wed, 31 Aug 2011 06:42:29 -0700 (PDT)
        Subject: Re: [Small4-strokeEngines] electric generator


        <!--
        -->


















         









        If you are interested in sterling-and generators here is a link that may be of interest
        http://www.whispergen.com/main/technology/
        Tom Steedman

        --- On Wed, 8/31/11, mrk@... <mrk@...> wrote:

        From: mrk@... <mrk@...>
        Subject: [Small4-strokeEngines] electric generator
        To: Small4-strokeEngines@yahoogroups.com
        Date: Wednesday, August 31, 2011, 8:32 AM

         

        hello everyone
         
        it's me again with odd questions"waiting for good energy density batteries" (zinc-air?) i believe that keeping the end part of the propulsive chain in electric (=the motor ;-) it could be viable making a hybrid vehicle that has a combustion-something producing electric energy and then feeding this to the motor. electric motors run on a 90% electric efficiency, just recalling this.they do this hybrid stuff already in prototype/projects.... somehow use fuel cells or turbine electric generator.... all stuff for the big pockets.
         
        don't need a full-power electric generator. just to sustain economic cruise speed... the long part of the trip. will use some batteries for extra power during takeoff, go around, climb... electric motor weight is not a problem (i recall, current brushless motors surf around 4 kW/kg (power out/motor weight))by the way, if any of you is thinking on solar cells, at current efficiencies (~20%) you can fly at about 50-70 km/h at ultra-best (i have quite a good deal of computations, if anyone is interested), with a very (ultra) clean design and of course midday sun. solar cells can yes be used for recharging your batteries, as you are not flying. it takes a while, though. it all depends on how you cut the cake (type of flight, intended use, etc.)off-the-shelf piston electric generator do weigh. one can get rid of all the fancies they use (the frame, wheels, etc) but they will still weigh, even if one thinks on eco cruise power to be put out. anyone knows of a
        good one, by the way? say around the 6-8 kW figure to start with.
         
        sometime ago i wrote about stirling free piston engines (or did i dream to write about it?) used as electric generators. they do this on solar plants (mirror concentrators). "just" an oscillating piston, a coil and magnet.... and voilà, the AC current is out. seems interesting, on a weight perspective too. imagine, no crankshaft, no valves, no nothing. "just" a piston going up and down, a magnet attached to it, and a coil around the magnet. somehow hey, worth a thought!
         
        the stirling cycle is external combustion. just make heat somehow, then "plug" the hot part of the engine into the heat source and it will work. seems interesting, on alternate fuel perspective too.so, to resume
        anyone knowing of a good electric generator?anyone with directions to alternative electric generator fashions, for small pockets?
         
        mrk

        [Non-text portions of this message have been removed]

        [Non-text portions of this message have been removed]


























        [Non-text portions of this message have been removed]
      Your message has been successfully submitted and would be delivered to recipients shortly.