Double Range Electric Aircraft: Distributed Propulsion

In this video, we are going to look at distributed propulsion and how it can double the range of an aircraft.

Information from the following articles were used in this video:

Distributed Electric Propulsion Effects on Existing Aircraft Through Multidisciplinary Optimization

Epema, H., Wing Optimisation for Tractor Propeller Configurations, Master’s thesis, Delft University of Technology,
June 2017

Alba, C., Elham, A., Veldhuis, L. L. M., and German, B. J., “A Surrogate-Based Multi-Disciplinary Design Optimization
Framework Exploiting Wing-Propeller Interaction,” AIAA, June 2017.

[FredPauling]

Interesting video as always. The efficiency multiplier for distributed propulsion is amazing! I can imagine small regional airports coming back to life with an increase in electric STOL aircraft services.

[TheGazmondo]

I love that you find so much new and interesting information. I just love this channel !

[elkcircle]

Interesting presentation of the benefits of ESTOL over EVTOL for many applications.

[philv]

Best panorama of these i've red or watch so far. Very instructive and conclusive.

[AntonEMaes]

there's a lot of focus in this space on making Uber's business model work but I can see this type of craft really revolutionizing general aviation and hopefully improving the safety record.

[flightvision]

Yes, finally. Real efficiency improvements over getting a brick to fly.

[loungelizard]

Short-range use is exciting! You can get 4 miles/kwh with USTOL (Ultra-short Take Off and Landing) if you can live with a 100 mile range, which is well within commute/recreational use! Even those high-maintenance, high fuel use helicopters never travel more than about 50 miles from base. I could see every TV station (if they still exist) ordering one to replace their "traffic copters", and Med-Evac very quickly shifting to multi-motor EVTOL (special case where VTOL is required).

[bikebrains]

This channel just keeps getting better and better. Keep up the good work!

[unbreakableldorado]

I love this channel so much, keep going! I believe nothing can accelerate the transition to sustainable aviation as much as public interest and support!

[kitwolf]

Something I feel worth discussing: One of the big issues for current electric aircraft is the need for reserve endurance - if a problem develops at your destination airfield, you need to be able to fly to another one. These reserves are relaxed for helicopters as in an emergency, they are more likely to be able to land safely without an airfield. This means that aside from other advantages, in comparison with a conventional aircraft a VTOL vehicle should be able to make better use of its ultimate range.

Thank you for a very interesting video. I learned a lot from it.

[bernardthedisappointedowl]

Love the depth and thought put into your content, ^oo^

[Savan_Triveda]

Amazing. We should really go for it. Less pollution, less roads, more flexibility, less traffic jam, more live quality, more terrain for agriculture, shorter commute between X and Y, lots of advantages. Smaller plains, less components, saver, cheaper, less CO2 footprint, more aesthetic, less dependence from large companies with goal to exploit you. Go for it!

[gerrybeylerian]

Very good video as always!

I wanted to share some constructive feedback (hopefully!) though that your focus was more towards the takeoff performance than the range aspect in my opinion. (Ex: @6:15) Takeoff is such a small phase of flight that its power requirements are sometimes insignificant to the range.

It's clear that there are benefits to distributed propulsion. Since lift is proportional to the speed square, the relative velocity increase provided by the small propeller can give large gains in lift. Additionally, the Reynolds number is increased, and typically the CL is higher with higher Re.

But the research you link also shows some compromises that have to be made for each application. Despite having a higher thrust to weight ratio with the smaller motors, the aircraft was 11% heavier than the base aircraft. I cannot see the study, but did the aircraft use less power to cruise even when it weighed 11% more? Because that's what really would affect the range.

[deldridg]

Exciting to see how we are gaining new insights all the time. This really helps me feel more positive about the future that awaits my children. As always, I particularly love your delivery - concepts are articulated with incredible clarity and always with context. You have an exceedingly rare ability to communicate at this level and I often refer to your videos when I am preparing presentations myself (I have been in management consulting around the globe for over 20 years). Regards and thanks from Sydney - Dave

[aliptera]

Some info presented here are not quite true. Distributed propulsion usually performs worse than a single rotor if you consider propulsion alone. This is due to degradation of the flow characteristics on the blade due to smaller Reynolds numbers. I have discussed this with Dr. Nick Borer from the NASA X-57 DEP CTOL aircraft team, he specifically mentioned the smaller propellers used for distributed propulsion were performing badly, about 50% efficient, and that's why at higher speed they are stopped and folded. What the distributed propulsion actually does - it increases artificially the wing lift coefficient, the wing can be much thinner, having a lot less surface area, without a reduction in stall speed, but having much better high speed performance. Having a smaller chord wing, same wingspan, increases the maximum L/D and moves this maximum at a higher speed on the L/D characteristics. The smaller wing actually is the reason the range increases, not the multitude of propellers. The distributed propulsion is to allow the wing to perform at slow speed and have a relatively slow stall speed, similar to the original larger wing.

[z_actual]

Two things come to mind
1/ that trailing edge or pusher propellers would endear a straighter, more predictable flow over the wing, especially concerning the leading edge; further optimising Clmax
2/ and Im unsure the advantage of short take off, as the present experience deals with 'average' take off durations quite well,
... and hull insurance on STOL aircraft has proven in the main to be commercially prohibitive
ok make that 3 things ....

[billhanna]

Thank you for your excellent work 👍👏👏👏... you have basically insinuated that we are about to see micro airports in the middle of bedroom communities around the country... quite and clean aircraft will change air travel completely

[crapisnice]

thanks for showing DEP and boundary layer ingestion. i think that with distributed propulsion is more appropriate to use closed wings as joined wings or box wings because it gives more structural stability and reduces flutter, a trade-off of distributed propulsion.

[antongromek]

Yo - this dude presents his stuff really well👌✍

[LoriCleveland]

Another amazing video, thank you! Is there any research on the electrification of high bypass jet turbines?