3hour flight time, a fuel-electric hybrid multirotor!

J

jlcortex

Member
Hi Everyone!

I would like to present a new project in which we have been working almost one year. We have been busy these days testing HYBRiX and we have good news!

Yesterday, we did an endurance test of 3 hours and 10 minutes!!!

The flight has been done with a full tank and the same configuration of the commercial product that we will be releasing soon. No auxiliary tanks have been used nor have we made a special lightweight version for the test. I leave you a photo of the moment.

hybrix_1p.jpg


It is a hybrid electric-fuel multi-rotor (like the BMW i3 for example).
Flight time could be about 2.5 hours with payload.

The goal is therefore to eliminate the limitations of flight time of an electric multi-rotor, while retaining the multi-rotor platform that I believe has significant advantages over other platforms platform.


Why are we doing a project?
As we all know, the drones have been a revolution in recent years. We think this is just the beginning, the market will grow to more professional applications in public safety, emergency, transport of small goods ... This is kind of what we seek with this new project, go out of the limitations of the electric multi-rotors and explore new possibilities.

3horas.jpg

We will release a video of this 3 hour flight in some days.
jlcortex
 

Old Man

Old Man

Active Member
Long flight times with a hybrid are often viewed like the holy grail in multirotors and I commend you on your compact design. The trick is to generate enough power to not only fly the aircraft and the bulk fuel supply, but to also carry enough additional useful payload to perform work aside from running the motors. Glow fuel engines, even those using modified fuel injection systems, consume too much fuel for the watts produced. gasoline two strokes do much much better, especially when experimenting with BSFC. It's been proven that running on the lean side of peak can minimize fuel consumption while maximizing watts, but provisions for excellent engine temperature control become necessary when running lean of peak. EFI systems on gas two strokes also work great for this task but their cost and complexity make them difficult choices to make for anything that cannot command very high selling prices.

I think you and Curtis Youngblood are currently neck and neck in your flight times. Keep up the great work!
 



violetwolf

violetwolf

Member
This is significant. Search And Rescue, military and civil surveillance, agriculture.. the list goes on.

Can't wait to hear more!
 

Old Man

Old Man

Active Member
jlcortex said:
Old man, Do you mean Curtis are working on a long endurance gas stingray?
Click to expand...

Not a Stingray, but otherwise yes. It's past the general design and R&D stage last I heard. I was doing some work on my own in this area but ran out of money.
 

ProfEngr

ProfEngr

Member
Are you using a Sullivan generator system? Those, so far, the only ones I've found to be anywhere near light enough and still produce a decent power output.
 

Old Man

Old Man

Active Member
They work but the workmanship can get dicey, even with their UAV product line up. They also have to be pretty large to obtain enough useful wattage, meaning the engine size needs to be above ~35cc too. In glow 2stroke engines the fuel penalty for that large of an engine prohibits their use.
 

ProfEngr

ProfEngr

Member
Convert the glow to diesel? I remember kits advertised to do that from 20yrs ago. But yeah, I ran some SWAG calcs on power (~2600W) from a post Ferdinand made and came up with a need for at least their mid-size unit to just hover. Then there's the regulation and governor systems........

It's not quite 'above my pay-grade' but definitely out of scope for the free time I can muster lately. I had plans back when to do a twin based loosely on the old Viper TV series using gas trimmers. Never could get the engine thrust to sync, but had plenty of extra lift for payload. One of them just wouldn't rev as much as the other. I shelved the project shortly afterward.
 

Old Man

Old Man

Active Member
I've actually done most of what's been discussed so far. Gas 2 strokes can be run effectively on heavy fuels but the BSFC does not increase by much. Forget about a glow conversion to diesel, the formula for the fuel used has to be hand mixed and it's not even close to fiscally viable. The solution is found in a combination of heavy fuels and fuel injection. You do not gain in power but you do obtain substantially improved fuel economy. But you lose much of that back to increased cost, additional weight, and a very complicated fuel delivery system which consumes it's own share of electrical power. The concept does not become viable until in a super heavy lift category. The most promising area of operations occurs when using an aircraft that also incorporates an aerodynamic lifting body. Dead lift stuff like multirotors consume too much energy by having to generate 100% of the lift required 100% of the time via propellers, so there's no point at which power can be reduced due to an offset with aerodynamic lift. There's also a tremendous weight/payload penalty because of the additional engine and fuel weight.

Oh, for twin combustion engine operations always set things up to be controlled by the weakest side. This is another area that benefits with EFI systems because the fuel metering can better control RPM stability. Now you know what I do for a living;)
 



ProfEngr

ProfEngr

Member
Sullivan regulators are heavy (1.50 kg) and 24-36VDC; not really practical for any but heavy-lift MR applications. Though I guess the weight wouldn't be that much of an issue when a 50+cc engine is aboard.
 

Old Man

Old Man

Active Member
ProfEngr said:
Sullivan regulators are heavy (1.50 kg) and 24-36VDC; not really practical for any but heavy-lift MR applications. Though I guess the weight wouldn't be that much of an issue when a 50+cc engine is aboard.
Click to expand...

Uhhh, yep;)

As for the Wankle inquiry, they just aren't reliable and very high maintenance. To get where you need to go with a Wankle you really need a twin rotor engine which suddenly puts the weight of the engine up there with fairly standardized 2 stroke gas engines. Gas 2 strokes engines can be very low maintenance and have useful life cycles of over 1000 hours, even with hobby level engines...when run on gasoline. That life cycle decreases a bit with heavy fuels. Another nice thing about a gasser, if you learn how to tune everything using a heavy fuel, which IS tricky, manage to get the stuff atomized small enough to combust efficiently, and use a spark assisted combustion process, you won't need the super heavy engine case required with a diesel nor will high pressure fuel delivery systems be needed to move the fuel. If you're really savvy you heat the fuel before it enters the engine. Do it right and you don't end up fussing with it all the time. Feed it, change the plug on a regular schedule, clean the air filter once in awhile, and just go fly. The Wankle won't let you get away that easy.

Ultimately the best way to get away from batteries is with fuel cell technology. It miniaturizes effectively but the cost of using it is so high only outfits like governments and military's can afford it. Boeing has been doing a lot of work with fuel cells and sUAS and it's looking pretty good. Really high dollar though and the peripherals are just as expensive .
 
Last edited by a moderator:



You must log in or register to reply here.
Top