Comments by "Brian B-P" (@brianb-p6586) on "Искаженное восприятие" channel.

  1. There have been several comments about the amount of airflow. A manufacturer of similar engines (there are many almost identical engines available) gives specs for their equivalent size (the P130-RX from JetCat): Name: Value Pressure ratio: 3 Mass flow (kg/s): 0,3 Consumption Full load (ml/min): 441 @ 130N Consumption idle (ml/min): 100 Weight [g]: 1326 Dimensions of the diameter (mm): 99 Length (mm): 284 Exhaust gas temperature (°C): 490-720 Idle speed (1/min): 40000 Max rpm (1/min): 127000 Thrust at idle (N): 4 Thrust @ maxRpm (N): 130 Exhaust gas velocity (km/h): 1560 Exhaust gas power output (kW): 28,2 SFC @ maxRpm (kg/Nh): 0,185 441 ml of kerosene is 355 g, and 355 g/minute is 6 g/second. So that's 300 grams of air and only 6 grams of fuel flowing per second, a mass ratio of 50:1. To burn kerosene completely requires 15.6 times as much mass of air as of fuel, so the engine is moving about three times as much air as it needs to burn the fuel; that's excess air, and that's normal for a turbine engine. The thrust results from increasing the momentum of the air; the energy to do that comes from the heat of burning the fuel.
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  2.  @sartajsingh6303  seems like you don't understand enough to know that it is real.
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  3.  @glenturney4750  "suck, squeeze, bang, blow" is for gas and diesel engines, because their combustion is intermittent. In a turbine engine the combustion is continuous - you need something other than "bang".
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  4.  @450ktm520  No, it's not a turbine without any compressors - that wouldn't be a working engine. Like any turbojet, it has a turbine which exists only to drive the compressor, because there is no shaft output (it's not a turboshaft or turboprop engine). It is the simplest type, with only one shaft carrying one compressor stage (which happens to be centrifugal in this case) and one turbine stage (which happens to be axial flow in this case). More stages can be used for a higher pressure ratio (the Brayton equivalent to ann Otto cycle engine's compression ratio).
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  5.  @morten-punnerud_engelstad  Sure, except that industrial gas turbines ran in continuous duty before the internet existed.
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  6. The name "Liquid Piston" is ridiculous and kept me from bothering to look at it, but it does seem like an interesting design. Aside from the merits (or lack of them) of the engine... great video of it running.
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  7. Sort of yes, except that the Wankel housing really is peanut-shaped, meaning bigger at the ends than in the middle (it's technically a two-lobed epitrochoid), while this rotor is a simple oval (semi-circular ends connected by straight sides). Similarly, the Wankel rotor can be a simple Dorito-like triangle (although in practice the sides are usually circular arcs, which is a Reuleaux triangle, to increase the compression ratio), while this engine has a rounded three-lobed housing. They're related, but not the same shapes.
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  8.  @구독자500명되면이같은  Matt did some great work here with the clear housing, but apparently you don't realize that he did not design the engine and did not build the components that you see him pulling out of plastic boxes. I can work on my computer, but that doesn't mean that if I lived in the 1940s I would have been able to build one.
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  9.  @Hogger280  it would take four Honda EU7000is generators to barely keep up with the Teslas demand at highway speed... and those are 118.1 kg (260.4 lbs) each. Between them, they would burn 12 L (3 US gal) per hour, resulting in worse fuel consumption than a normal non-hybrid car.
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  10.  @RobertoRaymon  there's a huge difference between "completely quiet" and the racket of this garbage
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  11.  @wilsonpalmpre  he wasn't even trying. In the video, the car isn't even in the far corner of the lot, and that wouldn't be far enough anyway.
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  12.  @14goldmedals  Possibly. JetPol builds a similar clear-housing demo engine of about the same size (their housing is borosilicate glass) and a YouTube video of their engine running on a similar table includes the table sliding on the floor and being pushed back into place... it's amusing to watch.
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  13. Isn't it just "N", rather than "N1", when there's no "N2"? 😉
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  14. Fuel flow is continuous. Yes, it is ignited by a glow plug initially. Yes, combustion is self-sustaining after start, just like any burner. Yes, the power control (not really a "throttle") just changes the rate of fuel delivery. No, there is not a significant pressure difference through the combustion chamber. Moderate amounts of water don't cause a problem in a turbine engine, and actually improve power output by providing more mass of working fluid. Deliberate water injection has been used to boost takeoff power in some aircraft, but this is no longer used, perhaps because it's not worth carrying the water
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  15.  @nutzeeer  you don't need to build a pile of junk like this to test that. The car shows energy consumption on its display, and you know the generator output for the generator you're considering and the number number of hours per week that you're willing to run it. By the way, the answer is "none" - it makes no sense to run a portable generator instead of buying electricity from a utility.
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  16. The basic geometry was used for steam engine by Cooley (1902) and an attempted internal combustion engine by Umpleby (1908). This company (Liquid Piston) dug up and old design and developed their version of it.
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  17. The parts which are not shown being made were purchased from a turbine engine manufacturer.
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  18. Gas turbine engine specifications include a "pressure ratio", rather than "compression ratio" (which is actually a volume ratio in a piston engine). An engine with a single-stage compressor like this typically has a pressure ratio around 3:1.
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  19. Mostly poor efficiency. They also respond very slowly to power changes, so they only work well driving a generator in a hybrid system.
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  20.  @upgrader99  Maybe, but it's not that bad. Imagine that you are pulling something heavy up to some height with a rope. No matter how fast or slow you pull it takes the same force to maintain a steady speed (just the weight of the thing you're lifting) but the faster you pull it the harder you have to work (more power). Power equals force times speed. 🙂
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  21. Sure, just fill up your tank with that highly compressed air that grows on trees. 🤣
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  22.  @AjayAjay-gz3oz  So you take your solar-generated electricity and use it to compress air, losing much of the energy it the process, then you put it in your car and use in an air motor, losing more of the energy. If a compressed air tank could hold a useful amount of energy, it might be worth the inefficiency.
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  23. Lousy, like any simple turbine... but with no fuel flow information and no power produced, there's no good specific answer.
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  24. Yes, it's close to a turbocharger with a combustion chamber instead of the piston engine.
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  25. No, there is no bypass. This a basic turbojet, not a turbofan engine. The "wires" are small tubes carrying the fuel to the burners.
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  26. It's not generating any power. Matt (Warped Perception) replied to other comments that the (maximum) thrust is about 30 pounds. Yes, four of those screws can hold that.
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  27. The ratio of intake (ambient) pressure to the pressure leaving the compressor stage is very low in these simple single-stage engines (much less than a gasoline engine) but in much more sophisticated modeern large engines it is typically over 40:1.
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  28. About 320 grams of fuel per minute at full power.
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  29.  @patrickfle9172  the engine which Jetpol built around 2010 has a borosilicate glass tube housing; I don't know how they produced the tube or where the obtained it.
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  30. That was one of the two interesting things that I noticed. It makes sense because the intake end of the combustion chamber is cooled by the incoming air, so temperature increases in the flow direction as combustion adds heat. The other interesting thing was the thermal expansion which the builder noted in the video.
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  31. But you wouldn't be able to see them except as a blur, due to the rotational speed, without an extreme slow-motion camera.
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  32.  @alexholker1309  The stator is also a diffuser, slowing the air flow down to increase pressure (as well as redirecting it from outward and spiralling to rearward and relatively straight).
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  33. The flames don't change much, but the temperature pattern of the combustor changes due to increased airflow.
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  34.  @justgonnastay  maximum rotational speed will be roughly proportional to impeller or turbine diameter... so yes, much bigger means much slower. I found a set of specs for the LM2500 listing a shaft speed (probably for the power turbine, not necessarily the gas generator which could be faster) of 3600 RPM; that's consistent with the size, which is likely more than ten times larger in the diameter of the rotating elements - it runs over 200 times the airflow and substantially more than 200 times the power of this little machine.
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  35. This is a commercially produced control panel. Look up documentation for Swiwin turbine engines for details, but the "fuel" number is proportional to the rate of fuel flow.
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  36. It's not perpetual motion or free energy - the energy comes from burning the fuel. Some of that energy is needed to compress the air.
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  37. Matt didn't "forget" anything - this is a existing turbojet engine design. It is very basic, but it works for the purpose (which is usually flying radio-controlled scale model aircraft).
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  38. Just like a poorly operated diesel, attempting to put in too much fuel causes smoke and soot.
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  39. The parts - other than the clear housing - are from a manufacturer who sells them to hobbyists.
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  40. It's apparently not glass; Matt says it is his proprietary composite, which I assume means a composite of polymers. The similar engine by Jetpol uses a borosilicate glass tube with a 5 mm thick wall (just under 1/4 inch).
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  41. Yes, all of these tiny "jet" engines use a starter motor - you can see it on the front of the engine.
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  42.  @abhilekhR1  Yes, 30 pounds of thrust, which is about 130 newtons (130 N).
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  43. Minor error: the diameter of the rotor 75 mm, so the is half of that, and the rest of the numbers are too high by a factor of two.
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  44.  @marquizzo  ah, sorry - I was thinking that this is a 100 mm diameter turbojet, but that's apparently the turbine diameter, not overall, with a larger compressor impeller.
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  45.  @ThomasGabrielsen  if the engine is rotating at constant speed there's no angular acceleration. You may have meant centripetal acceleration, which is the acceleration toward the centre of rotation required to stay on the circular path. That's a=v²/r (with "v" as the tangential speed and "r" as the radius), or a=ω²r (with "ω" as the angular velocity). Angular velocity is 2πN, where "N" is the speed in rotations (per second) rather than radians, so a=(πN)²r Okay... N = 127,000 RPM / 60 min/sec = about 2,000/s r = 75 mm = 0.075 m so a = (2π*2000)²*0.075 = (approximately) 12,000,000 m/s², or 1,200,000 times the acceleration of gravity This is high compared to an ultracentrifuge used in a lab to separate components of a sample. It's a brutal challenge for the construction of the rotating components.
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  46. Yes, it is a gas turbine.
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  47. Yes, in any turbine engine you add fuel at a higher rate to make more power, but you can't change the fuel flow too quickly or it won't keep running properly.
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  48. The company which sells a similar engine with a clear housing uses borosilicate glass, but Warped Perception has his own proprietary material.
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  49. Turbofan engines do move more air (at a lower speed, and mostly only through the fan) than turbojets, but even turbojets produce thrust only by accelerating air... so yes, they do move a lot of air. An engine of this size moves about 300 grams of air per second, which is 18 kg/min, 14 m³/min, or 500 SCFM; that's using specs from JetCat, which makes a nearly identical engine to this Swiwin design. Is that "a lot"? Matt's comment about "80 pounds of thrust means 70 pounds of air" doesn't make sense by itself, since a mass of air would only be meaningful with a time frame included (and other reasons). I believe he's referring to a rough rule-of-thumb that the weight (not mass) of the air moved per minute is about the same as the thrust produced by the engine. This is just the result of the typical exhaust velocity of basic turbojets, but does roughly apply to his engine: the weight of air moved per minute (about 180 newtons for 18 kg) is a number similar to the thrust of the engine (about 30 pounds or 130 newtons).
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  50. It was apparently glycerine fog, but that still has no hope of staying as droplets in the engine.
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