Questions tagged [aerodynamics]
Aerodynamics is the study of how air moves and interacts with solid objects. It is an essential part of aircraft design.
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aerodynamic forces on an engine cowling
In Mendenhall's book about the Gee Bee racers, he describes that on the Models Z, R-1, and R-2, there was a strong tendency for the engine cowl to get pulled forward and into the prop during races, ...
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Can someone recommend a good book/paper on understanding shockwaves over aerofoil? [closed]
I’ve been trying to understand shockwaves around an aerofoil from some contour plots I saw here and on the internet, but I’m struggling to understand them
Can someone please recommend a good book on ...
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Does lift requirements change as fuel is burned? If so, how?
so when an aircraft flies in cruise, it burns weight and so what impact does this have in lift requirements?
Would there be a need to also deflect flaps to stay in cruise as fuel is burned?
— I’m ...
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How does a zero g aircraft work?
In upward motion, drag and gravity is in the same direction (both in downward direction). So in this situation G is negative or less than 1 or something else?
In downward motion with thrust greater ...
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Why do fighter jets fly upwards very steeply when gaining altitude when lift is optimum at around 15 degrees?
Or is the thrust : weight ratio larger than one so they can fly vertically without losing speed?
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Trying to understand this pressure distribution over an aerofoil?
can someone please help me understand why the pressure is like that over the top and bottom surface of this aerofoil please?
Also, what do the arrows point out mean? Why are the front and end ones ...
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Why do the Comet's engines point outwards?
As it's visible from the images below,
when looking at the plane from the top, the engines point outwards and they are banana-shaped, why is that?
(unfortunately I couldn't find a real photo ...
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What is the physical explanation for the pre-stall judder in a Spitfire?
From the book "First Light" by Geoffrey Wellum, where the author describes dog-fight manoeuvres against an Me 109:
If you want to shake someone off your tail you have to fly your
Spitfire ...
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What does the NCrit parameter indicate in a CFD analysis?
When analyzing an airfoil in the XFLR5 software I am asked to input some data regarding the free stream. For this, a dialogue box pops up that has the following options:
One field contains the ...
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Shockwave motion with angle of attack [duplicate]
why is the shockwave picking in itself off the aerofoil with increasing deflection of the leading edge?
Angle of attack:3degrees
Aerofoil: naca0018
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What are the complete assumptions and final conclusions from 'Thin Airfoil Theory' in aerodynamics?
I possess expertise in the field of aerospace structures, however I have recently been assigned an 'Aeroelasticity' analysis job at my workplace. In an effort to imbibe the fundamental knowledge which'...
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Which one of these flaps is used on take off and land?
I’m really confused about which one of these flaps is used on take off and land?
I didn’t even know there were different types, I thought that the top configuration was the only used one today?
Also, ...
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Would spinning bush planes' tundra tires in flight be useful?
Short take off and landing bush planes are often fitted with very large diameter and width tires, so called tundra tires so that rough terrain can accomodate to the plane when both meet.
Sometimes ...
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Why are trailing edge flaps used for landing? [duplicate]
Why are flaps used when landing? Doesn’t a flap increase lift?
Edited: why are there so many different flaps on the back of a wing? Isn’t one just used when taking off and landing? Are the others ...
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Disadvantages of the Fowler trailing edge flap?
I get that the trailing edge plain flap has disadvantages (like tendency to separate flow as I read on a question on here)
But what’s so bad with the fowler flap? Aren’t they like really efficient and ...
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How to calculate the shear centre of a wing?
How is shear centre of a wings calculated? i.e. how can I calculate the wing shear centre of a two spar wing with main spar at 0% of wing chord and rear spar at 75% of wing chord? (Assuming the two ...
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How to measure chord on a rounded trailing edge airfoil?
So, should I measure it by the rearmost point (in contact with the tangent line) or the point coinciding with the end of the camber line (represented by the line starting at the circumference center)?
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PZL-104 Wilga and Wilga 2000 slats question
Looking at some details about this aircraft's wing, I wondered why the latest version slat's design
has been modified so that it is no longer a continuous slat that runs the whole wingspan, rather ...
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Do high wings aircraft create an additional vortex in the middle?
At the same time, the air on the upper surface has a tendency to flow in toward the fuselage and off the trailing edge. This air current forms a similar vortex at the inboard portion of the trailing ...
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How can angle of attack for a T-tail configuration be 21 degrees without stalling and also be flying at its trimmed condition?
I was reading a paper that looks at deep stall for T-tail configurations, and figure 2 suggests that the first trim condition for the aircraft in question occurs at approximately 21 degrees. Surely ...
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Does tailless delta configuration retain any advantage over conventional configuration with straight wings at high subsonic speeds?
For a model aircraft designed for cruise at say 0.75 Mach, do delta wings offer any benefit over straight wings. Is drag saving from elimination of the tail large enough to consider a delta ...
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Is this method to calculate a biplane's center of gravity using 57% of the biplane's gap and 23% of each wing's MAC correct?
Once you have the MAC for both wings and the CG balance point as a percentage of the MAC. connect the two CG positions with a line. Measure up between the wing Gap distance and place your center of ...
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Why do shockwaves move aft with camber/trailing edge deflection? [closed]
Why does a shockwave move further towards the trailing edge with increasing camber?
Also, is the shockwave the thing above the aerofoil or behind it?
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What is causing these "corners" on this F-104 V-n diagram?
In this V-n diagram for an F-104 (source: this Wikipedia link), on the left-hand edge of the flight envelope, what is causing the "corners" that we see at the following points? (Numbers are ...
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What is the typical drag percentage of air intakes on a commercial airliner
I see several questions on the NACA ducts found on airliners Example 1, Example 2, Example 3 and I was wondering how much drag is normally generated by these inlets?
As they take in air, I imagine ...
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Can someone help me understand this aerofoil?
I came across this morphing aerofoil, but don’t understand how it works please?
Can someone explain also what the components are, like that box in the left?
I looked into that reference, but it’s a ...
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Can a wind tunnel simulate airflow when a vehicle goes around a curve?
In real life, airflow in a turn is curved, how does a wind tunnel simulate this condition?
If we just yaw the test object at some angle in wind tunnel, do we simulate the airflow in correct way?
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Trailing edge flaps use [duplicate]
Why is it that trailing edge flaps are only used at lower speeds?
Can they be used at higher speeds too?
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Center of Gravity, Aerodynamic Center and Center of Pressure, how do they connect?
I read an article that described static margin by taking the aerodynamic center and the center of gravity. It explained why the center of gravity has to be in front of the aerodynamic center for a ...
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How to approximate the drag for rectangular vertical flat panel placed along the wind and inclined?
So on the top is the view from the top, below it is the side view.
If the angle is zero it is similar to simple flat airfoil.
So I calculated the Cl and Cd in xfoil and
got the Cl = 0 and Cd = 0.02398 ...
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Is it possible to install a bike rack on a Cessna 172?
I stumbled upon a nice photo manipulation on aviationhumor.net.
Source
My question is short and concise:
Is it practically possible to do that? Is it okay in terms of aerodynamics, weight, CG?
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Is there an aerodynamic benefit of covering the underside of wings?
What is the nature and extent to the benefit of covering up the bottom of an airfoil?
It seems like all the early airplanes just had ribs and spars that were wrapped only on top, but then pretty soon ...
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Aircraft spoilers (flight spoilers, GLD)
Wondering if anyone has any examples on how a spoiler affects the Cl and Cd of an airfoil.
For example, Xfoil has plenty of data on plain flaps up to 45 degrees deflection but nothing about spoilers. ...
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How does increasing camber increase lift coefficient?
How does increasing the camber of an airfoil (like the NACA 0018) increase its coefficient of lift?
You're just curving the airfoil; I don't see how that increases lift for a given angle of attack?
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What is airflow direction in turn?
Let imagine that we put wind indicator on rotating merry-go-around.
Will wind indicator stay prepedicular to the radius of circle,showing tangetinal airflow velocity?
(Wind indicator has equal mass ...
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Aircraft progress: Evolution or design? [closed]
This video of a Curtiss Pusher is stunning. Had I been around when it was new, I would have stopped there!
Question: What processes led to the aircraft of today?
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Trailing edge flap disadvantages
What does ‘high local surface curvature’ mean with respect to trailing edge flaps?
I’ve been reading up on them, and that came up as one of their disadvantages?
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Does the Fairchild Metroliner have any unusual handling characteristics?
I have been told by several people that the Fairchild Metroliner is a quite difficult to handle aircraft.
Aside from that, I have seen that it has suffered several accidents throughout its history.
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Why do autopilot controllers use $\theta$ as the input signal rather than $\gamma$?
In particular, referencing how the Matlab/Simulink controller here uses $\theta$ (absolute pitch angle), rather than $\gamma$ (flight path angle). (Autopilot controller starts at 59:26)
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Will the V280 operate with only one engine?
Can the newly contracted Bell V280 Valor operate on one engine?
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What would happen if a hot air ballooon was punctured in mid-air?
I am writing a script for a film where a hot air balloon is punctured and it falls to the ground. There are two teenagers in the balloon when it is in the air. What I would like to know is how fast ...
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Why isnt the structure of the aircraft affected by high true air speeds or high ground speeds?
Let's suppose that in Cruise flight I exceed the VNE in TAS or in ground speed, why isn't the structure of the aircraft affected by the high speeds?
I am sorry for my english, I am not a native ...
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Can I identify wingtip stall by looking at the lift distribution?
I'm projecting a wing in XFLR5. The lift at the tip of the wing looks like it's dropping very quickly close to the stall angle, so I think there may be wingtip stall, however, is there any way I can ...
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Why does elevator trim hold a given airspeed? [duplicate]
I'm trying to understand a principle described in the book Stick and Rudder by Wolfgang Langewiesche between angle of attack and airspeed in relation to the elevator trim. He states that as angle of ...
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How does propeller length, pitch, and airspeed affect efficiency? [closed]
tl;dr: trying to find propeller efficiency with thrust, velocity and power and see which propeller length to pitch ratio is efficient.
Hello, I'm a high school student working on an extended essay for ...
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Is there a simple relationship between angle of attack and lift coefficient?
Is there an equation relating AoA to lift coefficient?
I have been searching for a while: there are plenty of discussions about the relation between AoA and Lift, but few of them give an equation ...
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What would be the minimum number of engines required to climb in a 747?
There was a really good Air Crash Investigation by Nat Geo which showed the British Airways Speedbird 9 issue where volcanic ash swept over all four engines and through the air vents inside the cabin. ...
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How does varying camber affects control over an aeroplane? [duplicate]
How does a trailing edge flap actually help an aeroplane?
It just changes camber but what does that exactly do that’s beneficial?
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Mathematically calculate Mach number using CAS and PA WITHOUT flight computer
I am just wondering how to calculate the Mach number from CAS and Pressure Altitude WITHOUT the use of a flight calculator.
E.g Given FL300 (30000ft) and 325kt CAS find and Mach number.
I have always ...
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Do stall strips mean that wing washout is not required?
The Wikipedia page on stall strips states that AA-1 Yankee airplanes used stall strips to avoid tip stalls (and spins) because wing washout couldn't be used.
So my question is: can two stall strips ...
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