Tech Tuesday 04/02/19 – “I Live In A Madhouse This Week” Edition


Oscar Gordon

A Navy Turbine Tech who learned to spin wrenches on old cars, Oscar has since been trained as an Engineer & Software Developer & now writes tools for other engineers. When not in his shop or at work, he can be found spending time with his family, gardening, hiking, kayaking, gaming, or whatever strikes his fancy & fits in the budget.

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9 Responses

  1. Avatar DensityDuck says:

    [TT8] So this is neat but I also remember how the Aerospike Engine was gonna fix everything and we still aren’t using them. (And how Waverider hypersonic designs were gonna fix everything before that, and we aren’t using those either, beyond some purpose-built research vehicles.)

    Not to say it’s a bad idea that won’t work, it’s just that regenerative-cooled turbopump-fed conical nozzles are a pretty solid incumbent and it’s going to take more an incremental improvement to knock those out of place.Report

  2. Avatar JoeSal says:

    [TT8] My bet is they will run into material issues. 😉

    A lighter engine can be built if they use a natural aspirating pulse jet that internally converts to ram jet at about mach 0.70. The turbines just add weight. Material science will catch up one of these days.Report

    • Avatar Oscar Gordon says:

      I think the material issue will be one of cost rather than ‘we just don’t have it yet’. As in by the time they get one working, the savings over a traditional SRB will have diminished too much for anyone to care.

      We have a lot of amazing materials in the MatLib, but many of them can only currently be produced in small batches at great cost, and they are just waiting for the right application to justify larger batch production. Now if the Pentagon suddenly decided this was a great way to get satellite killers into orbit…Report

      • Avatar JoeSal says:

        Imagine beating a piece of combustor metal with a >14 pound pressure hammer at 60-200 times per second……do that for 15 minutes…..Now imagine the hammer is at 900F heating each time it contacted followed by a splash of cold air.

        It’s going to take something pretty sturdy, and probably pricey.Report

  3. Avatar Kolohe says:

    Tt7 – I’m guessing 1.2 MW is peak power output? I couldn’t find that stat in the article or the website, nor an energy capacity number in some (10^3 series metric prefix) Watt-Hours.Report

    • Avatar Oscar Gordon says:

      That’s either a press release for lazy journalists, or it’s a press release for vaporware. My first clue was “unique phase change material”. It’s sounds like a good idea, and if they got one working, could be useful, but the presser smells a bit fishy. If anyone finds better information, feel free to link to it.Report

      • Avatar Michael Cain says:

        The diagram at the site shows a heat engine for conversion from stored heat back to electricity. Unless they can produce quite high temperatures, the efficiency of that step will not be very good.

        My standard for comparison is the pumped-hydro station up the road from me. If the upper reservoir is full, four hours at 320 MW maximum output. Round-trip efficiency is a bit over 80%.Report