Yep, you heard me right, I'm going to build the world's first supersonic RC plane, almost doubling the world's present RC speed record. Reason why I'm doing this is to get the attention of the aerospace industry so that they might consider me someday.
Yes, I know the technical challenges will be enormous, but that is why I am doing this, to demonstrate what I can do. Plus it will finally be a chance for me to put my degree to use.
Now the biggest challenge will be finding a place for me to actually fly supersonically, not that every flight has to be supersonic. I am aware that when airplanes travel at that speed a sonic boom is usually created. However, since this design will be smaller, so will the sonic boom.
Another concern of mine will be heat, as air friction compresses the air, heating it up. The temperature I estimate I will reach will exceed the maximum of some of the components, so I will need some sort of cooling mechanism, and just fans won't cut it.
Now I know some of you may have alarming concerns, but if you calmly address them with me I will address them. I'm posting this here because I may need advise for the type of parts I need and other recommendations you may have.
Aerospace V logger out.
Replies
Its an Interesting project! Have you considered the following factors
> Airframe design
> Power plant
> How will you control the aircraft at your intended speeds.
If you do manage it build it at your assumed budget... there will be lots of interested parties in your project from around the world. 3K is very low budget for such an ambitious project.
Anyway good luck and keep us updated on how you get on.
Airframe design:
Almost a flying wing with a lengthy fuselage for the engine assembly. The wing tips will be the tails, and the elevons will be mounted on top of them. Also the wings will be swept back at a 45 degree angle. What type of airfoil type should I use for Mach 1.1?
Power Plant: An EDF with ethanol-fueled augmenter. The platform can fly in all-electric mode but not supersonically without burning fuel. Imagine the RC equivalent of a hybrid car. Also it will use a linear aerospike nozzle in order to save cost and weight.
Control: Well, one of the bigger concerns of mine will be the range of the FPV and remote control equipment. I'm going to need some serious range booster equipment for my ground station. Another concern of mine will be how to install the antennas without any signal interference or the supersonic aerodynamic forces shearing them off. What do you advise?
Are you able to share the theory upon which you have based things like wing span, wing sweep, fuselage length, material selection, etc?
Have you selected the 45-degree wing by calculating the optimum sweep using linearised theory or simply gut feeling?
Have you done any flow modelling on the distribution and concentration of heat that will be generated at the speed you intend to fly?
What hardener do you plan to use for your CF body? What is the curing point of the hardener? Is that temperature within tolerance?
Why are you considering an active cooling system? Is there no possible passive solution?
Why CF and not aluminium or titanium?
Have you calculated the overall lift and drag coefficient of the finished aircraft?
Have you quantified how much thrust will be required for this aircraft to reach the speed you intend to fly? What is it that gives you the confidence that a modified version of a $50USD EDF motor is up to the task?
How long do you intend for each flight to be? How much ethanol would that require? How big is the LiPo you plan to use? What is the combined weight of liquid fuel and chemical battery?
How do you envisage FPV being of use to you on an aircraft which is travelling at ~380m/s?
Quick couple of questions
Are you planning to close the air intake into the EDF once the Ramjet kicks in.?
What size airframe are we talking here?
What do you think the weight of the complete craft would be just before take off.
Mach 1 is about 340m/s. Assuming you reach the target speed, the craft will be traveling almost 41KM every 2 minutes. What kind of radio gear will you be using to ensure you remain within range?
Are you aware that the FAA only authorizes super sonic flight for military use above 10 000 feet and prohibits supersonic flight for all civilian aircraft (in most cases .. the Concord was the only civilian jet permitted to go supersonic until it was retired)?.
Supersonic flight testing of ANY aircraft may also only be done in certain locations on the planet and these tests are very very strictly monitored and regulated. Where are you planning to fly this beast you building.
Everything you said sound very much like theory at the moment. Do you have any CAD or mathematical models "in action" you can share?
Again wingspan around 3 feet or 1 meter. So far I'm thinking the weight will be about 10 lbs or 21 kg.
As to where it will be flown supersonically, I was hoping you can fill me in on that. I guess I could fly it over the ocean, where supersonic flight for the Concord was authorized.
As for the mathematical models, I do have some excel spreadsheets I've created, but it is partially based upon guesswork. I need to still put together raw aerodynamic data.
Any further questions?
:)
I suppose over the ocean sounds good .... if you only want to do one flight and then go on a deep see diving course to selvage the $3000 craft.
Perhaps the desert ... just need to work camel rental into the budget...
You'll still need FAA approval ... I'm thinking they'll love your idea of a supersonic FPV jet.
I'm still wondering what radio gear you're going to use. Although some RC transmitter systems claim they can cover an area of 50km odd using directional antennas, that will be done in less that 3 minutes of flight.
Then there's the issue that the earth is not flat. So on the beach the horizon is 35km away from you. For every 100m increase in height of of the viewer, the distance you can see increases with 4.6km for the first 100(theoretically .. since we're into theory here.) For every 100m elevation after that the viewing distance decreases exponentially due to the unfortunate shape of the planet .
What kind of stresses on the airframe do you expect on the plane when you hit the mach 1 mark.
Oh and before i forget ... how much fuel will you be carrying. Ramjets are known for there fuel economy ... or rather the lack thereof.
With that level of precision you will succeed before you know it.
Good luck
Hey AerospaceVlogger,
an interesting project you have there.
A question concerning your fuselage: Can you supply a sketch of your intended fuselage? You say it is not a flying wing, but "The wing tips will be the tails". I cannot quite imagine the difference between what you describe and a flying wing... Did you also consider strucutural issues? Will it be made out of carbon fiber or what do you intend to use?
A question about control: Do you plan to fly it line-of-sight, or do you want to use an automatic control system?
Cheers
phil
I want to up one # Ben Norris:
I will go for MARS !!!!! :P
Funny you should mention that because for the next project I was thinking about something that could reach space. It would not be a sustained orbit just a sub-orbital lob. As for propulsion it would be a variation between a rocket and ramjet, depending on speed and altitude. If you know some of the problems of rocket design you would realize using local resources for propellant would save a LOT of weight. That is why the majority of the mass of a rocket is usually fuel/oxidizer, and planes only need enough fuel to fill the wings.
But this is another topic for another time, after I've finished this one.
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