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.

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Can we add treadmill-like structures over the airplane surfaces to reduce friction, decrease drag and producing energy?

I am curious about a method to enhance the efficiency of passenger aircraft during cruise speeds by integrating treadmill-like structures on the fuselage and beneath the wings without changing the ...
Siames's user avatar
  • 81
0 votes
0 answers
56 views

SU2 vs OpenFoam for highly unsteady aerodynamics. Suggestions?

I am trying to simulate aerodynamic interactions between high speed propeller downwash and wings of a cruising aircraft. Confused between OpenFoam and SU2. Open to other opensource software ...
Pamraat Parmar's user avatar
0 votes
0 answers
30 views

Calculate Air Conditioning Duct Pressure from Sources and Users

I am currently modeling a high fidelity simulation of Boeing 747-200 for a flight simulator, and I am now at the stage of programming what is essentially the HVAC system for the aircraft. I will try ...
Christopher Helton's user avatar
0 votes
2 answers
53 views

Is a centrifuge force-based levitation system operable in the real world?

In the sci-fi comic Betelgeuse, the artist Leo presents a flying car with an unusual system for levitation and propulsion. The interesting point is that at the end of the comic, there is a page on ...
totalMongot's user avatar
1 vote
2 answers
138 views

Infinite life of a material, Fatigue Strength

After 10^6 cycles a component is considered to have infinite life. What makes 10^6 cycles a deciding factor for infinite life? Why not 10^8?
Reo Ashwin's user avatar
0 votes
0 answers
30 views

Pitot and static port placement - How to choose the ideal location

Forgive the this topic placement as it might be similar to other older ones (Although I a bit sure that the main contents might be different than other older ones). In the upcoming days I will have a ...
Theodosis Koutsoukos's user avatar
1 vote
2 answers
147 views

Why does the air in a jet engine not flow out of the front?

It is my understanding that jet engines work via the ,”suck squeeze, bang blow process”. The main fan introduces air into the engine, and the compressor blades squeeze this air into a higher pressure ...
Richard's user avatar
  • 11
0 votes
1 answer
45 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
SACHIN SAJIKUMAR's user avatar
0 votes
1 answer
84 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 ...
Jimmy G.'s user avatar
0 votes
1 answer
116 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 ...
Rameez Ul Haq's user avatar
3 votes
2 answers
107 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 ...
Mohamad Ghasemiyan's user avatar
1 vote
1 answer
70 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. ...
GunMan's user avatar
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0 votes
3 answers
70 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 ...
Bruce Adams's user avatar
0 votes
2 answers
242 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 ...
user57467's user avatar
  • 271
1 vote
1 answer
35 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 ...
user39178's user avatar
  • 113
1 vote
5 answers
217 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?
Francis L.'s user avatar
2 votes
0 answers
331 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 ...
Diesel's user avatar
  • 632
-1 votes
1 answer
54 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 ...
scico111's user avatar
  • 109
2 votes
3 answers
64 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 ...
cup's user avatar
  • 233
-1 votes
2 answers
42 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-...
Audley Kosick's user avatar
4 votes
1 answer
949 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 ...
ychnh's user avatar
  • 59
4 votes
2 answers
3k 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?
Rajakr's user avatar
  • 338
2 votes
0 answers
200 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 ...
Ibrahim Jaafar's user avatar
2 votes
1 answer
49 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 ...
Amitabh Sharma's user avatar
2 votes
3 answers
68 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 ...
Adrian's user avatar
  • 131
1 vote
1 answer
541 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 ...
John's user avatar
  • 111
0 votes
1 answer
42 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 (...
Gleb's user avatar
  • 1
0 votes
1 answer
203 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?
Rajath Pai's user avatar
3 votes
0 answers
329 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 ...
emrys57's user avatar
  • 155
0 votes
1 answer
142 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 $C_l$...
chithebot's user avatar
0 votes
3 answers
99 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? ...
toto's user avatar
  • 103
0 votes
2 answers
76 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 ...
Teslov Valentin's user avatar
3 votes
2 answers
360 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 ...
Teslov Valentin's user avatar
4 votes
2 answers
11k 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?
Shinu_John's user avatar
1 vote
0 answers
54 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 ...
Élio Pereira's user avatar
1 vote
0 answers
71 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 ...
nd97's user avatar
  • 11
1 vote
1 answer
182 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 ...
Shadow Clan's user avatar
0 votes
1 answer
71 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 ...
Lin Ko's user avatar
  • 1
0 votes
1 answer
323 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.
Lin Ko's user avatar
  • 1
0 votes
1 answer
80 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 ...
Real's user avatar
  • 111
2 votes
1 answer
110 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 ...
AEhere supports Monica's user avatar
6 votes
1 answer
9k 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 ...
emcyaman's user avatar
1 vote
1 answer
2k 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 ...
E. Pence's user avatar
-7 votes
3 answers
419 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
87 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. ...
bobKnowsBest3199's user avatar
3 votes
4 answers
413 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 ...
bobKnowsBest3199's user avatar
0 votes
1 answer
734 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 ...
Nick's user avatar
  • 5
4 votes
1 answer
161 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?
nowox's user avatar
  • 293
3 votes
0 answers
177 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 ...
Frank's user avatar
  • 179
0 votes
2 answers
587 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 ...
p.pensopositivo's user avatar