how to calculate wing foil ?
>>1014933
sorry, my question was unclear.
lets say that my plane weight 1400 KG and has a top speed of 900 k/h how much lift do i need @ X speed ?
>>1014937
1400kg or more
>>1014937
hey man, so i'm actually an aerospace engineer.
in order to have the math explain how much lift you need at a given speed for success, you need to first understand the given values for the force that can be exerted on "aircraft" by air;
so what this means is that you need 1400 kg or more of
lift
nice
let me know if you have any more questions.
>>1014980
why do I find it not surprising an "aerospace engineer" doesnt know the difference between force and mass?
>>1015005
Ok I'll be serious now, you need 1400 kgf of force or 13720 newtons
>>1015018
To answer that you first need to undertand what wing loading is.
Lift is dependant on the shape of the wing, the speed, angle of attack, and altitude.
There isn't one quantitive way to say how much lift a wing produces, instead you need to find how much lift it produces under certain conditions.
>>1015019
>Lift is dependent on the shape of the wing, the speed, angle of attack, and altitude.
thanks, i'v figured that out, and i know the equation.
thats not what i was asking
>>1014933
Lift is proportional to velocity n wing area according to the handy equation L=Cl * .5p*V^2 * A
You could have found this out in less time than it took to save that image and make this post. Anyway, you need to decide at what speed you reasonably expect to be going at from propulsion, find reasonable weight, then solve for wing area. You also need to look at types of airfoils and their characteristics but that's what you can work on.
>>1015022
maybe my question wasn't clear.
should i put, lift (L) @ maximum speed = plane weight
or put lift (L) @ X speed = plane weight.
if my lift is 1400kg @ 450 k/h, wouldn't that be a problem @ 900 k/h ?
>>1015037
assuming the plane weight is 1400 kg
>>1015037
So you wanna know if you should calculate for area at cruise speed or takeoff. Planes usually account for the difference in speed by altering the wing area through moving actuators called "flaps" and "slats". So more area at lower speed, less area at higher speed. What you could do if you're just making a fuggy shitbird to fly in and immediately crash is just use your takeoff speed. Keeping a large area means that you'll be limited to an optimal lower speed unless you want to burn off that lift force by using a rudder to apply downward counterforce.
>also lift is a force not a weight kys
>>1015037
I can t even begin to imagine how stupid some one have to be to want to build a fucking air plane and dont bother to make some research on the basics of how planes fucking fly. And he's even doing some attitude to an aerospace engineer that wants to help him.
God, please help us
>>1015040
>using a rudder to apply downward counterforce.
rudder applies lateral force
elevator applies upward or downward force to adjust pitch
>>1015196
:DDDDDfug
>>1015196
it's flying sideways.
>>1015196
Rudders can apply downward force if there's 2 of them pointed in opposite directions like /\ where downward is the current planes direction. Since Rudders are angled they direct the air in to the tip of the /\ and upward, causing a down force on the tail. This also works if the rudder splits open to increase drag. The air is split by the V and the angled shape causes a downward force.
Not the aerospace engineer. Just a regular engineer who works with aircraft daily. Not sure how that helps the situation as described but any redirection of air flow upward will cause an equal downward force on the surfaces causing the airflow to change direction.
>>1015263
>by using a rudder to apply downward counterforce.
>a rudder
While your premise is correct, it is not relative to the referenced post. (a rudder, not tail-feathers or multiple rudders)
>>1014937
aircraft usually have a takeoff speed of 100-250kph.
you need to figure out what you want your takeoff speed to be.
the faster the takeoff speed, the longer a runway you need, obviously.
so what you probably NEED for your plane to be an airplane is 1400kg lift @ 100kph.
does that answer your question?
>>1015452
Not OP but if the plane is made to have a fast takeoff, it means it will not be fast in the air ?
>>1015764
One doesn't necessarily have to correlate to the other.
>>1015452
don't think so, keep in mind i'm talking about flaps being at 0° angle with the rest wing.
if i get 1400kg lift @ 100kph my lift @ 900kph would be ridiculous. and i would keep going upwards till the egde of space.
i think my maimum lift (not counting the flaps) should be 1400kg @ 900kph.
the flaps will give additional lift at lower speed.
correct me if i'm wrong
>>1015808
You are wrong at a certain speed high lift aircraft will break apart. You will not go to space either, frankly I'd be amazed if you made a scale model out of chopsticks and elmers glue
>lets say that my plane weight 1400 KG and has a top speed of 900 k/h how much lift do i need @ X speed ?
You aren't DIYing a fucking airplane so what you ARE doing is asking someone else to do your homework.
Worse, you are too lazy to Google. KYS all spoon feed requesters.
>>1015808
>>1015808
>don't think so, keep in mind i'm talking about flaps being at 0° angle with the rest wing.
that's good to know
>i think my maimum lift (not counting the flaps) should be 1400kg @ 900kph.
maybe maybe not.
>the flaps will give additional lift at lower speed.
maybe.
you need to realize that you can't go 900kph wherever you want. you will need to know your desired cruising altitude.
plug that altitude into the barometric formula, and plug the resulting pressure into this formula:
(100kPa/Pressure)*1400kg = required lift @ 900kph.
>>1015824
that was an image.
>>1015841
> you will need to know your desired cruising altitude.
thats beside the point, i already know that air density will change the lift.
>>1015846
are you fucking retarded you stupid piece of shit?
you wanna go 900km/h while mowing your lawn?
>>1015846
Listen, anon, we're trying to help but you just keep saying "Yeah, I know that".
You keep trying to oversimplify lift to a almost static nubmer.
Also, you really should take a look at wing loading
Abandon this shit thread
>>>/trash/
>>1015918
thats because no one is answering the question.
yet it's pretty clear.
you're trying to fake knowledge by getting into an argument with me.
its not the first time i have to deal with insecure people on 4chin.
>>1015923
See? Rather than ask a genuine question or consider factors like wing loading, you resort to ad hominem and/or projection.
We can answer your questions, but you want a answer too simple to be of use.
Your plane weights 1400kg? Then you need 1400kg of lift.
Foil shape, angle of attack, wing loading, atmospheric conditions, altitude, flaps, speed and many other factors influence how much lift you are getting.
What we're trying to say is that finding how much lift you need is the easy part, finding under what conditions your wings will produce that lift is the part you need to focus on.
If you make a wing that doesn't produce enough lift at a low angle of attack then you simply increase your angle of attack or increase speed.
If that wasn't satisfactory than make the wing larger.
Lift can be controlled through angle of attack and speed too much for us to simply give you one magical "lift" number.
>>1016000
>one magical "lift" number.
it's over 9000
>>1014933
plane's name?
I'm an AE major, and it doesn't sound like you have a good idea of what you're up against. Take a look at the book at this link for help with understanding how to design and analyze a plane.
https://www.dropbox.com/s/dv8hhiry6xyva02/Aerospace%20Boot%20Camp%20v2.1%20%282009%29%2C%20Johnson.pdf?dl=0
It is important to first define the mission profile, then do sizing constraints, and then begin design on the form of the aircraft.
/diy/ is an interesting board because it's browsed exclusively by the smartest and the stupidest on the site
