The "Beast One": What doesn't kill you makes you stronger

Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by Scheny, Mar 11, 2019.

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  1. Mar 11, 2019 #1

    Scheny

    Scheny

    Scheny

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    This is the thread where I present the concept of the "Beast One". Unlike the title, it is the goal to create an economic BD-5 alike single seat jet which on the contrary to the BD-5 won't try to actually kill you.

    The plane is not about re-inventing the wheel, nor to follow this stupid higher, faster, stronger philosophy. The only goal we have in mind is to be better! When you are bound to something as unefficient as a turbojet, the rest has to be even better to compensate. With the FLS Microjet (unchanged successor of the BD-5) and the JSX-2 there are already two competitors, but it goes without saying that there is room for improvement against a widowmaker and a flying Hershey-bar derived from a low-tech motorglider.

    Passive Safety:
    With the knowledge of carbon formula car specialists, the fuselage will be built to endure up to 30G frontal, while incorporating a 80cm composite crumplezone capable of handling impacts at almost landing speed. In addition, the fuselage is built in a way to reduce frontal collision loads by around 30% and incorporate a BRS which can be activated up to cruise speed.
    Another relevant safety factor is a static stability unknown for such small aircraft, forgiving stall characteristics and an even lower landing speed than the JSX-2.

    Aerodynamics:
    Nobody can defy physics, but you can switch to state-of-the-art. We decided against unforgiving laminar profiles in favor for profiles which are an advancement over the proven NACA 64xxx, having 23% more lift at exactly the same drag (and even more forging stall characteristics). The profiles have been developed with help from Dr. Quabeck and the quasi-elliptical wing has outstanding slow-flight qualities while still being efficient for high cruising speeds. The tail is dimensioned bigger than comparable aircraft and meets the recomendations for jet-trainers. The fuselage is built to minimize wetted area and interference drag without risking flow detachment.

    Key data:
    The plane is built around a PBS TJ-100 engine putting out 1100N of force and pushing the 380kg MTOW to between <60kt (to fulfill CS-23) and an economy cruise speed of 200kt (top speed ~300kt). It will be built aerobatic capable with an ultimate rating of 14G but normal use is restricted to 6G for engine reasons.

    More info to follow...
     
  2. Mar 11, 2019 #2

    Scheny

    Scheny

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    This is a comparison for required thrust over flight speed calculated using detailled 3-views of the BD-5J, the JSX-2 and the Beast One:
    Comparison.png

    For landing speed, it even outperforms the JSX-2, while having good economy up to 230kt. The sweet spots have been set to 120kt for best endurance and 200-220kt for maximum range.
     
  3. Mar 12, 2019 #3

    Andy_RR

    Andy_RR

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    Why do people fall into the trap of making sweeping and outrageous definitive claims about a paper aeroplane? Some of the numbers here are on the border of credibility with no means of independent sniff testing. Is this project Raptor 2.0...?

    Aren't things supposed to get better as the version number climbs?
     
  4. Mar 12, 2019 #4

    Topaz

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    I don't mind high goals and claims, but we really do need more information before anyone can judge the credibility of this project. Hopefully that will be forthcoming soon.

    Scheny, would you mind sharing more of the project, and how your performance numbers were derived? Are these aspirational, or have they been affirmed by analysis? If so, would you mind showing us some of the basics of that work? I'm sure the members would like to know more.
     
  5. Mar 12, 2019 #5

    Scheny

    Scheny

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    Actually, if you check the comparison I stated the conservative numbers and not the optimistic values from the comparison. Basically I do not pretend to have much better values than the JSX while our wing was reviewed by two independent aerodynamic specialists and both have been impressed it didn't originate from a big factory (and roughly confirmed the predicted numbers).

    Compared to Raptor there is one big difference. I rely on the expertise of my team and I am not ashamed of taking their advice. This is why the tail has already been modified twice and why I asked in this forum for advice on the fuel tank system. While I am the key person driving this project, there is the continuous support of two aerodynamicists, two carbon chassis experts and one testpilot, so I can assure you it is not a castle in the sky.
     
  6. Mar 13, 2019 #6

    Victor Bravo

    Victor Bravo

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    I think it's safe to say we're all waiting for the digital rendering of this machine that provides a visual image of what you are proposing.

    One of the OP's posts mentioned detailed 3-views, but I cannot find any of those 3-views in this thread.

    Is this aircraft concept being presented here in the "pre-3-view" stage? That is not automatically a negative, many of us have proposed discussions for concepts that have not progressed to the 3-view stage. I have recently psoposed such a concept myself.
     
  7. Mar 13, 2019 #7

    Andy_RR

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    Trust me, I'm all for pushing the limits of what's possible but if you post a bunch of huge claims backed only with a graph that has no visible ordinate axis, I'm calling bullshït until proven otherwise.
     
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  8. Mar 13, 2019 #8

    Scheny

    Scheny

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    You see it in my avatar. I hope you don't mind I don't want to include a full resolution yet.

    We started independently in two groups with students doing a concept study and constraint analysis and me, doing concept study for one potential customer. After the student project finished, we joined forces and now it is "my" child, but with support from many capable people.

    My approach has been:
    .) Configuration Selection
    .) detailed requirements study
    .) mission definition
    .) comparison to competitors
    .) Conceptual Design
    .) Powerplant --> only PBS was left
    .) Initial sizing (came from constraint analysis --> turned out complete bull**** for our mission)
    .) First sketches
    .) Preliminary Design
    .) Profile selection --> we decided against critical ones and for a mixture between low landing speed, efficient cruise and aerobatics possible
    .) Aerodynamics (wing) --> VLM2
    .) Aerodynamics (non-wing) --> turned out to be similar to Arnolds concept for the AR-6
    .) Weight --> detailed list for every single part to be used, fuselage based on input from chassis experts
    .) Regulations (CS-23 compatible)
    .) Cost estimation for first prototype
    .) Comparison to BD-5 and JSX-2 --> VLM2 simulation + CFD for cruise condition to roughly validate VLM2
    .) Configuration Development
    .) Ergonomics --> mockup tbd next, some tests with coarse foamplates mockup done successfully
    .) Avionics chosen
    .) Systems --> configuration almost done
    .) To continue here...

    As you see, there is a lot going on in the background. I would not call the rendering in my avatar a final solution yet ;)
     
  9. Jun 6, 2019 #9

    Scheny

    Scheny

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    So, yesterday I have been shopping material for the 1:1 scale mockup of the front fuselage section (not enough space for the empennage at my own workshop). This will be used for checking the ergonomics (up to now done via CAD). I had one car load of XPS foam and we speak of a Mazda 6 station waggon.

    The plane is designed "inside out", due to the space restrictions like in a glider. So also for the mockup, I will begin with a center-section of the seat and then optimize while adding the "sides".

    As the response for the "Airplane 05" thread was positive ("finally someone building a plane upon engineering"), I decided to make most of our engineering available (with some data being excluded of course) in this thread.

    I hope this will diffuse your concerns about my claims a little bit.
     
  10. Jun 6, 2019 #10

    radfordc

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    I would hope not. A jet with no air inlet would be strange indeed.
     
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  11. Jun 6, 2019 #11

    Scheny

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    Due to non-disclosure and time issues, I can only give you a small peak at the data. The raw data is many pages long:

    Part #1: Configuration Selection

    Requirement study
    • Gross weight 380kg (calculations for 450kg as safety margin)
    • Single pilot, 120kg max.
    • Stall speed clean <60kt
    • Cruise speed ~220kt
    • Vd/Vne >300kt
    • 150l (40gal) Jet A1
    • Part23 compliant
    • +9G/-5G
    • Ergonomic, >60cm (23") at shoulder
    • Reduced workload (for a jet)
    • Easy handling characteristics
    • >26G frontal / 10G other directions safety cell
    • BRS available as standard, built in crumple zone in nosecone
    • 1100N jet engine
    Define mission
    • Max. endurance >3h @120kt
    • Max. range 550nm excl. reserve
    • 30min aerobatics, 3min sustained inverted flight minimum
    Study aircraft in similar class
    JSX-2, BD-5J, Beast One
    Crew 1, 1, 1
    Length 5,1m, 4,0m, 4,5m
    Span 5,5m, 5,1m, 6,0m
    Wing area 5,6m², 3,5m², 5,0m²
    Airfoil 64-415, 64-215, Beast 15%
    Empty weight 227kg, 188kg, 180kg
    Gross weight 454kg, 370kg, 380kg
    Fuel capacity 150l, 113l, 150l
    Powerplant TJ-100, TJ-100, TJ-100
    Stall speed with flaps 50kt, 67kt, <60kt
    Cruise speed 209kt, 208kt, 220kt
    Never exceed speed 249kt, 278kt, >270kt
    Range with 30m reserve 417nm, 200nm, 550nm
    G limits +4,4G +6G, +9G
    Rate of climb 1600fpm, 2400fpm, 2400fpm
    Fuel consumption 68l/h, 68l/h, 68l/h
    Ballistic recovery Yes, No, Yes
    Handling charac. Good, Bad, Good
    Safety cell No, No, Yes


    Study aerodynamic goals

    • Soft stall characteristics (special profile: derived from 64-215, but better stall and Ca at low Re)
    • Emphasis on low Reynolds behaviour (for outer wing, due to smaller chord)
    • Decreased interference drag at wing junction (fuselage design + nonlinear fairing)
    • Decreased interference drag at tail (elevator placement)
    • NACA turbine inlet (high alpha behaviour, ice accredition,...)
    • Spoiler design (evaluation of wing, tail or even split rudder)
     
  12. Jun 6, 2019 #12

    Scheny

    Scheny

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    Back when we draw it, it was not clear where the turbine will sit (CG was not finished calculating) ;)
     
  13. Jun 6, 2019 #13

    BJC

    BJC

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    Why -5 g?


    BJC
     
  14. Jun 6, 2019 #14

    Scheny

    Scheny

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    We checked the data sheet of the engine and it only allows for 6G continuous and 9G peak. Because of that, we put the requirement to +9G (still evaluating weight penalty for 14G ultimate). For negative, we thought about redout and added some margin on top, so we came up with -5G. Due to the design of the spar, it will be more likely almost the same value as for positive.
     
  15. Jun 7, 2019 #15

    proppastie

    proppastie

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    its a tough crowd.....I think the issue might be some might think this thread should be in the "Supplier / Manufacturer Announcements" category. I personally do not care but perhaps you see my point.
     

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