Questions tagged [aircraft-design]

For questions about how certain features of an aircraft affect its performance and function, such as engine type or wing configuration.

Filter by
Sorted by
Tagged with
0 votes
1 answer
11 views

Failure criteria for CFRP single plate bolted joint

Which equation can be used to find failure based on ply orientation. Tension,shear & bearing faliure to validate against fem analysis
user avatar
0 votes
1 answer
78 views

What would cause more stress the airframe of a 757/767: 550 mph at 1,500 feet, or supersonic flight at 50,000 feet?

I was reading over some threads on metabunk.org about the 9/11 "Truther" Movement and it was brought up that a DC-8 was flown at supersonic speeds at 50,000 feet as an explanation for how ...
user avatar
  • 101
0 votes
1 answer
76 views

In an aircraft, should I connect flanges of wing spars' to the fuselage, or webs of wing spars' to the fuselage?

I am actually trying to understand which option is going to be a more relaible for the wing-fuselage attachment. Should I choose a connection between the flanges of the spars within the wing to the ...
user avatar
3 votes
2 answers
98 views

What is the reason for forbidding liquids for cooling in drilling on cfrp/Al or cfrp/Ti stacks?

I recently did some research on the effect of cooling on CFRP/Al7075 drilling.But I read somewhere that liquids are forbidden for cooling operations on these multi layer plates !!! , And I wanted to ...
user avatar
1 vote
1 answer
59 views

Which optical filter to use for flat black non-glare aerospace indicator?

I am currently designing a LED light indicator for use in an aircraft cockpit replica. I’m asking for expert advice on the type of lenses to use in order to get a result similar to shown pictures. ...
user avatar
  • 11
0 votes
3 answers
49 views

Are wind powered drones and platforms possible?

A glider is able to fly unpowered indefinitely so long as it can exploit nearby thermals and the like to stay aloft. The world record is 3,008km so perhaps there is a practical limit. I imagine this ...
user avatar
0 votes
2 answers
113 views

Will a lift force be created by the Coanda effect if high velocity air flows under a half-toroid shaped saucer? [duplicate]

I would like to know if a lift force will be created by the Coanda effect from high velocity air that is directed under a half-toroid shaped saucer by a centrifugal impeller. To illustrate how such a ...
user avatar
  • 249
1 vote
1 answer
30 views

If an airfoil underwent horizontal loading, would it stiffen the airfoil? [closed]

I am designing a wing for a Vertical Takeoff and Landing aircraft. I am trying to choose a wingtip winglet for my aircraft. One of the option is a aft-swept wingtip winglet. However, this structure ...
user avatar
  • 113
1 vote
5 answers
138 views

If an aircraft's wing blows air downwards, how is the momentum conserved in level flight?

An aircraft's wing generates force of lift by directing the oncoming airflow down. How is this momentum balanced when the aircraft is not climbing, but maintains level flight?
user avatar
2 votes
0 answers
154 views

Sutherland's law for other gasses

Sutherland's Law seems to be a fairly well-accepted relationship between dynamic viscosity and temperature and was originally created to work for ideal gases, though it is often extended to be used ...
user avatar
  • 632
-1 votes
1 answer
53 views

How to know the material of key-top?

There are keys (push buttons) on the front panel of an avionics device that fits inside the aircraft cockpit. I need to know the material of which those key-tops are made from. I can guess the ...
user avatar
  • 109
2 votes
3 answers
57 views

Can an empty aviation fuel tank blow up

At the end of the James Bond movie View to a kill, the aeroplane runs out of fuel - both the propellers stop and the plane glides. There are holes at the bottom of the tank so all the fuel has ...
user avatar
  • 233
-1 votes
2 answers
40 views

Is it true that pre-jet air planes used to fly much lower? If so, why?

I watched a video on the Concorde the other day. In it, they talked about the history of airplanes, and how the jetplanes now started flying "above the weather", and that the propellar-...
user avatar
4 votes
1 answer
928 views

How does a helicopter hover

I am wondering how a helicopter manages to stay balanced and stay in one spot while it is in the air. I understand that there is a second rotor that is used to counteract the angular momentum and also ...
user avatar
  • 59
4 votes
2 answers
2k views

In case a plane stalls, what should stall first, the tip or the root of the Wing? Why?

In case a plane stalls, what should stall first, the tip or the root of the Wing? Why?
user avatar
  • 328
1 vote
0 answers
125 views

what is the difference between jblade, qblade, and xflr5 softwares?

I am working on a propeller design, and I've came through Jblade which helped me in the airfoil design, yet as I can remember, xflr5 can also do this... doing some internet search, i found that Jblade ...
user avatar
2 votes
1 answer
45 views

Where can i get the aerodynamic data of aircrafts for controller design and testing?

I have some research papers on aircraft controller design that i want to simulate, but no system data is given in the research paper itself. I am also unable to find the aerodynamic data for any ...
user avatar
2 votes
3 answers
64 views

What engineering obstacles would need to be overcometo make a hot air balloon bigger than the largest made?

Average hot air balloons have a diameter of about 18 m. The largest out there is roughly 32 m. My question is, are there any reasons other than fuel concerns that would prevent having a larger ...
user avatar
  • 131
1 vote
1 answer
289 views

Aircraft Longitudinal and Lateral Transfer Function Terms

The figure shows input and output variables for both longitudinal and lateral stability transfer functions. I completely understand what each term stands for but I was wondering what would be the ...
user avatar
  • 111
0 votes
1 answer
41 views

Using RC scale-down model to pre-test aircraft design

I'm a bit involved into building an actual airplane. And while the guys go conventional ways, I'm trying to look around to see other solutions. One of that is to try and use and RC scale-down model (...
user avatar
  • 1
0 votes
1 answer
93 views

For a tangent ogive, given a radius, can you determine it's length?

A tangent ogive body has a specific radius for a given length, so how would you determine length if only given the radius?
user avatar
4 votes
0 answers
224 views

Boeing 737NG pickle fork cracking. What determines the fastener layout?

Boeing 737NG aircraft are currently being checked for cracking in the "pickle fork" assembly that attaches the fuselage to the wings. The affected joint has 4 fasteners that attach the fork to the ...
user avatar
  • 165
0 votes
1 answer
99 views

How do you determine the L/D ratio of F-117 Nighthawk?

I was trying to look for an L/D ratio published everywhere on the web and I can't seem to find it (for a project). Since I couldn't find it, I wanted to try calculating myself. Can't seem to find $C_l$...
user avatar
0 votes
3 answers
94 views

For how long could a plane handle turbulences?

Some days ago, I took a plane (Airbus A330) for a pretty long flight - around 8hrs. During the flight, we experienced some turbulences and I thought : what if the turbulences last the whole flight? ...
user avatar
  • 103
0 votes
2 answers
67 views

Heating the air inside a turbojet instead of combusting it

Would an aircraft that uses propellers for movement but with a turbo jet like structure where the ignition chamber only heats the air a bit, similar to a hair dryer instead of releasing fuel and ...
user avatar
3 votes
2 answers
260 views

Compressing the air thrusted by an aircraft's propeller through a cone like tube

If I had an aircraft that used propellers for movement and took the air from the front running it through a tube that gets very small towards the end, would it have any impact on the speed? Would the ...
user avatar
4 votes
2 answers
9k views

Multiple Varying cross section beam deflection

How do we calculate the deflection of a cantilever with two or three cross-sections, and different forces acting at the end of each section?
user avatar
1 vote
0 answers
51 views

Batteries for electric airplanes [closed]

I'm interested in the development of electric small airplanes with 4 or 6 seats, that could really happen in the following decades. One of the main problems related to this project would be the ...
user avatar
1 vote
0 answers
69 views

PID control for UAV [closed]

I'm working on a deltawing model airplane where I want to implement a PID controller to stabilize the pitch, roll and yaw (which are only controlled by two elevons). However, I don't know too much ...
user avatar
  • 11
0 votes
1 answer
142 views

Propeller design

I see on internet, that aircraft propellers most effective blades angle only 15 degrees on every blade. Why propellers not use 45 degrees angle on propeller's blade that give more thrust on the ...
user avatar
0 votes
1 answer
67 views

What action does a 3 axis gyro stabiliser do to stabilise the drone?

A gyro measures the angular velocity of a drone around 3 axes: yaw, roll and pitch, but what physical change does it make to the drone after measuring this value to give it stable flight? As it is a ...
user avatar
  • 1
0 votes
1 answer
273 views

What is the importance of pitch ratio? And why is the value different for different aircrafts?

I tried looking online, but all I can find is what pitch ratio is, butI can't find anything related to the question above. Help will be appreciated.
user avatar
  • 1
0 votes
1 answer
78 views

What technologies prevent drones from being as efficient as birds? [closed]

We have large scale aircraft with long endurance and much higher speed than birds. But it seems that aircraft of comparable size to birds (i.e. drones) have much lower endurance, top speed and flight ...
user avatar
  • 111
2 votes
1 answer
103 views

Name of a keel between the bilge keel and the main keel

I'm working on a seaplane and find myself doubting about the specific nautical term for a keel placed between the bilge keel and the main keel. This might be a bit academic in nature since I have a ...
user avatar
6 votes
1 answer
7k views

Do all airfoils have a lift curve slope of $2\pi$?

I know that according to the thin airfoil theory all airfoils (symmetric or not) have lift curve slope of $2\pi$. I also know that finite wings should have less inclined lift curve because of the ...
user avatar
1 vote
1 answer
1k views

Wingspan formula for an Ornithopter

How do i figure out what the wing area/sqft needs to be for a functioning wing-flapping ornithopter? Lets say for example there is 500# of force moving the wings up and down, and the wings and ...
user avatar
-7 votes
3 answers
387 views

Can a blimp enter Mar's atmosphere as a glider?

I saw a high altitude jump where someone had exceeded the speed of sound before the air slowed him down enough to deploy a parachute. While inflated in space could a blimp enter the atmosphere while ...
user avatar
2 votes
2 answers
80 views

Lift Requirements for Hybrid Airship

so I am very interested in flying. I don't have any formal education in the topic so take my questions for what they are. I was thinking about VTOL aircraft and the current state of such machines. ...
user avatar
3 votes
4 answers
402 views

Are rocket engines practical for commercial aircraft?

What are the prospects of seeing rocket engines become the standard for commercial aircraft? It might be a dumb question; I really don't know all that much about the topic. The reason I ask is that ...
user avatar
0 votes
1 answer
686 views

Will helium gas lift more weight in air when it is spread over large volume compared to equal weight heavily compressed small volume?

Is it possible for a weather balloons filled with helium gas to lift the weight of itself and a helium tank(highest psi possible) which can fit the volume of the lifting gas in it? Assuming a typical ...
user avatar
  • 5
4 votes
1 answer
122 views

What is that airplane headphone socket?

I recently flew on a A380 and I saw this interesting socket. Could someone explain to me what is the purpose of these 4 golden connections?
user avatar
  • 293
3 votes
0 answers
176 views

3D matrix for staggering 5 ten degree wide bands of angle of incidence shifted by target wavelength and optical path difference in arithmetic series

Today, we came up with the idea of creating a 3 dimensional matrix where I simultaneously stagger 3 times 5 times 5 Fabry Perot band-reject interferometeric filters with ten degree wide bands of ...
user avatar
  • 179
0 votes
2 answers
490 views

How can we prove that Thrust-to-weight ratio depends by max speed?

Raymer (see source below) affirms "Thrust-to-weight ratio is closely related to maximum speed". Why? How can we demonstrate it? Source: Daniel P. Raymer Daniel P. Raymer "Aircraft Design: A ...
user avatar
1 vote
0 answers
243 views

In Raymer diagram “Take off parameter- Take off distance”, what is the difference among “balanced field length”, “over 50 ft”, “ground roll”?

Raymer in his book Suggests a method to find Wing Loading W/S (for example we consider jet with 2 engines) (starting from specific thrust T/W, CLto, density/reference density etc.). In step 1: he ...
user avatar
2 votes
1 answer
77 views

Using propeller downwash for electronics cooling

I have a quadrotor aircraft (4 motors/propellers around a center housing) with some electronics in an electronics housing. Looking to cool the electronics with propeller downwash. I have a vent on ...
user avatar
  • 123
4 votes
3 answers
3k views

How an airfoil works

I have read on many sites that for lift to occur, the pressure below a wing must be higher than the pressure above it. This happens by somehow moving air faster over the top of the air foil so the ...
user avatar
15 votes
2 answers
6k views

If aircraft are pressurised, why do our ears pop during liftoff and landing?

Something hit me during my last flight: our ears feel that the pressure around us changes quickly during liftoff and landing, they hurt more and more until we make them pop. However, the cabin must ...
user avatar
8 votes
2 answers
2k views

Efficiency in a gas turbine or aircraft engine

Most modern aircraft engines, such as the one depicted below taken from Wikipedia, are composed of several compressor stages which are driven by a turbine (or several), and a combustion chamber in-...
user avatar
  • 342
7 votes
2 answers
1k views

What are the advantages of chemical oxygen generation over compressed tank storage?

Chemical oxygen generation (COG) is used in commercial airliners to supply emergency oxygen to passengers and crew if the plane is depressurized. Weight for weight it produces far more oxygen than ...
user avatar
5 votes
1 answer
109 views

How to store gas on little pulsejet plane?

I am thinking about building small plane with a pulsejet but the engine would need to be roughly 2 cm in diameter. Is it even possible to fit something to store gas on that sized plane? At least for ...
user avatar
  • 59