View Full Version : Wave Pulse Jet Engine
Interesting. Looks a bit Heath Robinson, but that’s not necessarily a factor in use. Not indication of cost vs a small turbine, or number of RC turbines. Mention of FADEC implies it’s not as simple as it looks.
https://www.twz.com/news-features/pulsejet-drone-flies-could-have-big-impact-on-cost-of-future-weapons
Pulsejet Drone Flies, Could Have Big Impact On Cost Of Future Weapons
The pulsejet-powered Scitor-D reflects growing interest in low-cost, high-performance engines for decoys, one-way attack drones, and more.
A Baltimore-based startup has recently flown an experimental drone powered by a pulsejet engine, a type of powerplant that has few moving parts, in contrast to a conventional turbine, offering the promise of low-cost jet performance.
Previously, the company, Wave Engine Corp., received U.S. Air Force funding to develop a decoy powered by a pulsejet — a powerplant best known for its infamous use in World War II (https://airandspace.si.edu/collection-objects/v-1-cruise-missile/nasm_A19600341000).
Meanwhile, the potential for the same propulsion technology to make it into other types of drones is something we have examined in the past (https://www.twz.com/41263/air-force-finds-new-need-for-low-cost-engine-tech-used-on-nazi-buzz-bombs) and is becoming even more relevant given the increasing applications for expendable types…..
https://cimg3.ibsrv.net/gimg/pprune.org-vbulletin/2000x1143/wave_engine_corp_scitor_d_demonstrator_aircraft_on_a_take_of f_roll_sourcewaveengine_com__d142b550fd00cadf1d97071e4b7211f 3a3205341.jpg
https://youtu.be/ijrTTAZP1zg?si=u4oQI5iFK0EixVHH
DaveReidUK
7th Mar 2024, 06:54
V1, Rotate ...
Ninthace
7th Mar 2024, 07:03
Looks like something out of Scrapheap Challenge but so long as it works.
I’ll note that both Ukraine and Russia are already using pulse jet drones…
https://x.com/micro_cabbage/status/1522785373906083840?s=61&t=rmEeUn68HhlFHGKbTPQr_A
https://www.dniprotoday.com/en/news/the-ukrainians-have-built-the-first-cruise-missile-it-is-a-powerful-weapon-powered-by-a-pulse-engine-521
MechEngr
7th Mar 2024, 07:24
If you want such an engine look up Robert Maddox; he has a youtube channel https://www.youtube.com/@RobertMaddox and I think sells plans and components so you too can be hated by most of your neighbors for pursuing this hobby late into the night. And by neighbors, I mean anyone in a 2-5 mile radius. The bigger ones go to 900 pounds of thrust. He is hilarious.
Santa has a sleigh, right? And it flies, right? So, aviation content that even Norad says they track. Here's Maddox's pulse jet propelled sleigh flying.
https://www.youtube.com/watch?v=yDRJItKqClk
Seems a bit vulnerable against IR missiles.
Then again, for a decoy, that’s not necessarily a bad thing….
hunterboy
7th Mar 2024, 08:43
You wouldn’t want that exhaust landing on top of you….
Thrust Augmentation
7th Mar 2024, 09:10
Interesting - nothing new under the sun & all that.
looks a bit like a scaled down A-10 with a roof mounted Avenger.
rans6andrew
7th Mar 2024, 09:31
An Ex plumber in the UK has been playing with these for a long time, amongst other stuff. He has turned his experimental and wacky stuff into a source of income by YouTube. See ColinFurze - mad inventor for how simple it is to make a "no moving parts" engine. He made a larger one, which he fixed to his truck, loud enough to be heard across the English channel (22 miles!) and went to the south coast to Fart at the French. If a turbo charger from a vehicle is added the efficiency can be increased but so is the cost. Enjoy.
Rans6...........................
muggins
7th Mar 2024, 09:50
Looks like something out of Scrapheap Challenge but so long as it works.
I remember an episode of Scrapheap Challenge where the idea was to build a rail sled powered by a pulse engine. It was scary the speeds produced at the run off. It also appeared to be quite noisy when running.
treadigraph
7th Mar 2024, 09:54
I love Robert Maddox, he is an absolutely delightful nutter!
Cornish Jack
7th Mar 2024, 10:43
Last time I saw (and definitely heard !) one of these, it was at an R/C model fly-in the 60s, at Burtonwood, IIRC. A Dutch team flew a delta wing version, very well, very fast and, just to repeat, very noisily !
If you’re using drones as a terror weapon, as with the V1, the noise is a plus, not a minus…..
NutLoose
7th Mar 2024, 11:29
An Ex plumber in the UK has been playing with these for a long time, amongst other stuff. He has turned his experimental and wacky stuff into a source of income by YouTube. See ColinFurze - mad inventor (https://www.youtube.com/watch?v=bCsg5pQimWI) for how simple it is to make a "no moving parts" engine. He made a larger one, which he fixed to his truck, loud enough to be heard across the English channel (22 miles!) and went to the south coast to Fart at the French. If a turbo charger from a vehicle is added the efficiency can be increased but so is the cost. Enjoy.
Rans6...........................
Err from my Aircraft Engine training in the RAF and yes I did Pulse Jets on the course, gawd knows why, ( mind you we did all the piston engine stuff as well, sleeve valves, radials, rotary's, the lot), you need shutters at the front that move, when the fuel lights the shutters close, then when it goes out and the pressure drops they open allowing air in. Hence the pulses...so it actually has moving parts, otherwise it would be a ramjet.
:p
Expatrick
7th Mar 2024, 11:35
Err from my Aircraft Engine training in the RAF and yes I did Pulse Jets on the course, gawd knows why, ( mind you we did all the piston engine stuff as well, sleeve valves, radials, rotary's, the lot), you need shutters at the front that move, when the fuel lights the shutters close, then when it goes out and the pressure drops they open allowing air in. Hence the pulses...so it actually has moving parts, otherwise it would be a ramjet.
:p
"The second type of pulsejet is known as the valveless pulsejet.[5] Technically the term for this engine is the acoustic-type pulsejet, or aerodynamically valved pulsejet."
I believe these are the ones where the inlet & outlet face the same way.
From Wikipedia.
NutLoose
7th Mar 2024, 11:42
Gotcha, we studied the one out of ermm.. V1, such was the RAF training mid 70's
It would seem t9 be a Lockwood-Hiller variant, a5 least they reference it in one of their own patents.
https://en.wikipedia.org/wiki/Valveless_pulsejet
https://patents.google.com/patent/US3462955A/en
https://patents.google.com/patent/US3462955A/en
Expatrick
7th Mar 2024, 12:24
Gotcha, we studied the one out of ermm.. V1, such was the RAF training mid 70's
Bang up to date then!🤣
tdracer
7th Mar 2024, 18:31
Mention of FADEC implies it’s not as simple as it looks.
Not necessarily - "FADEC" could be something as simple as a 99 cent CPU. Heck, look at what they did with a Furby, and that was 20 years ago.
Biggest drawback to a pulsejet (aside from the noise) is they are not very fuel efficient - probably not a big concern for an expendable drone.
Biggest drawback to a pulsejet (aside from the noise) is they are not very fuel efficient
From the article:
…“The company has also demonstrated its pulsejets using various different fuels: gasoline/petrol (87 Octane), kerosene-based fuel (Jet-A/JP-8), and sustainable ethanol-based biofuel (E85).
In terms of fuel efficiency, the company has demonstrated thrust-specific fuel consumption (TSFC) levels under 2.0 pounds/pounds-force per hour, which it says rivals the efficiency of more complex and expensive turbine-based engines.
Wave Engine combines its pulsejets with Full Authority Digital Electronic Control (https://skybrary.aero/articles/full-authority-digital-engine-control-fadec)(FADEC), in which a computer controls engine performance, and this may well be key to achieving the stated levels of efficiency, as well as optimizing performance more generally.”……
Santa has a sleigh, right? And it flies, right? So, aviation content that even Norad says they track. Here's Maddox's pulse jet propelled sleigh flying.
https://www.youtube.com/watch?v=yDRJItKqClk
Where does one put the bag of toys in that rig? The engine is taking up that location.
MechEngr
7th Mar 2024, 19:17
Where does one put the bag of toys in that rig? The engine is taking up that location.
I am not a snitch.
falcon900
8th Mar 2024, 07:44
Where does one put the bag of toys in that rig? The engine is taking up that location.
It is the toy, you stupid boy! He was delivering it to some lucky kid.
tdracer
8th Mar 2024, 18:17
From the article:
In terms of fuel efficiency, the company has demonstrated thrust-specific fuel consumption (TSFC) levels under 2.0 pounds/pounds-force per hour, which it says rivals the efficiency of more complex and expensive turbine-based engines.
Wave Engine combines its pulsejets with Full Authority Digital Electronic Control (https://skybrary.aero/articles/full-authority-digital-engine-control-fadec)(FADEC), in which a computer controls engine performance, and this may well be key to achieving the stated levels of efficiency, as well as optimizing performance more generally.”……
I guess it depends on what "expensive turbine-based engines" they are talking about. If they are talking a simple pure-jet turbine, they could perhaps get close to the same TSFC numbers. But when you start comparing to a modern turbofan, a simple cycle efficiency analysis would make competitive TSFC numbers wishful thinking.