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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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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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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Why does this site allow misleading answers to remain, and stay at the top of the stack? [migrated]
In searching for some relevant photos for a lecture I am writing, I came across a question "Does lift equal weight in a climb?". The first answer, with most upvotes, is not only very ...
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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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During starting dornier 228 engine found flameout 2 second what action need to be taken? [closed]
Honeywell TPE331 Engine of dornier 228
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Need help relating calculating Helicopter Lift [closed]
I’m a student doing a project on the relation between angle of attack and lift generated by helicopter blades and I'm having a little trouble. I need a method to calculate lift for a set of blades ...
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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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A shock propagates in to stationary air at M. Find the speed of the air (fixed frame reference) after the shock has passed [migrated]
The speed of sound prior to completion of the shock is $M_1 * a$, where a is the speed of sound at that point.
The solution is then that the speed of the air after the shock has propagated is $(M_1 * ...
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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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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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What is the additional planform area added to an A380 on take-off flaps setting (Flaps 1+F)
I would like to know how I can approximate the additional area added to wing on flaps 1+F:
Can someone use other dimensions they know of the A380 wing and approximate what this area would be, we can ...
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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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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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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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Why does the Tu-134UBL have a sharp/pointed nose cone?
Russian/Soviet aircraft design has always intrigued me, and even more so when coming across this photo of the Tupolev Tu-134UBL with its pointy nosecone.
Having looked up the performance ...
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Do box-wings suffer from induced drag the same way as normal wings?
Most wings suffer from induced drag due to a pressure difference above and below the wing causing air to sneak around the tip, forming a vortex. There are various methods to minimize these effects, ...
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Calculating best glide speed
I recently started flying a SGS 2-33 glider. The POH lists the stall speed as 31 mph for solo flight. Min sink speed is 38 mph and optimal glide speed is 45 mph.
Being an old glider with imperfections,...
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What should be the ideal distance between wings in a multi-winged air plane?
What is multi-wing or multi-plane:
For those who may not know, multi-wing air planes or multi-planes are aircraft that exceed the three sets of wings.
The idea is while increasing the number of wings,...
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Maximum Rotary Lift Altitude
Given that all factors are optimal, What is the physical maximum absolute ceiling altitude of a rotary wing aircraft?
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Rate and radius of turn formula
From this question and answer here there is a formula for both rate of turn and radius of turn. The formulas input are knots and degrees.
I have no doubt the constants in the formula (11.26 and 1,091)...
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Helicopter total power required: zero wind speed while climbing --vs-- down wind speed while hovering
I've been stumped on this for a while. Let's say you have a helicopter in climb mode (i.e., 100 ft/min) with zero wind speed present. Would the total power requirement be the same as if the helicopter ...
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The F104 tail pipe is not parallel to the runaway when the aircraft taxi.What is the reason?
The tail section is upward for clearance or to vector up the engine exhaust that will help to rise the nose when the aircraft take-off?
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Why do airplanes lift up their nose to climb?
Is it right that basically an airplane just needs to accelerate to climb?
Greater velocity of an airplane leads to greater lift - and since its weight remains constant (or even decreases) - a greater ...
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Streamwise Pressure Gradient on Curved Walls
Could someone help me to understand how can a wall generate differents streamwise pressure gradients just by its curvature? I can understand how it works in cross-flow (perpendicular to the streamline)...
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What does the pressure distribution over a glider's wing look like?
Can someone explain the design of glider wing airfoils and the subsequent pressure distribution over them?
I hypothesize that:
The pressure distribution should form a resultant force in the forward, ...
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Thrust = Drag. What about Power?
Understanding all this has been a work in progress, but now from start to finish we have:
Fuel/second ---> shaft Horsepower---> RPM ---> Thrust ---> Drag
Drag Force = $\rho$ × Area × ...
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Can an aircraft use ram air to generate power while flying?
I am a student carrying out a project focused on efficiency on aircraft. I have arrived at an idea I believe to be feasible. I am looking for suggestions, specification of what I would need, and any ...
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Lift direction at non-zero angle of attack for a swept wing, or for a straight wing in sideslip
When the direction of forces is popularly explained, they say "the lifting force is directed perpendicularly, and the drag force is parallel to the oncoming flow".
But what if it's a swept ...
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Could the Wright Flyer II takeoff without wind?
The Wright Flyer II could reach about 20 mph of airspeed on the track alone. The aircraft needed an airspeed of about 30 mph to make a proper takeoff (without hanging in ground effect). Before the ...
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Why is the tail group of virtually every airplane swept instead of straight?
Even low performance airplanes like ultralights have their tail group (vertical and horizontal stabilizer with rudder and elevator) swept backwards knowing fully well that a straight tail group will ...
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The F/A-18 Hornet , F15 and MiG-29 ailerons from the external parts of the wings go up some degrees in flight ,meaning adding " crow" .Why?
In some parts of the flying envelope of the F/A-18 Hornet and MiG-29 the ailerons from the external parts of the wings go up in sync. They're made to go one up one down in order to get rolls, not up/...
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Other than looking cool, what is the reason behind the TSR-2's anhedral wingtips?
Pretty much what the title says. What is the purpose of the TSR-2's anhedral wingtips? I've heard someone say that they use it to counter yawing I think but is this the true reason or is it something ...
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Why are the trailing edges of wings not always made as 'sharp' as possible?
I noticed that wing trailing edges of new airliners like A220 (CSeries) are not completely sharp. Instead, they are blunt. I always thought that the sharper the better in subsonic flow. What is the ...
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Subsonic Bump Inlet?
Contemporary high-performance supersonic aircraft such as the F-35 use bump inlet (alternatively known as DSI). These have a sophisticated 3-D bump that causes a 3-D weak shockwave in supersonic ...
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Why use indicated airspeed instead of dynamic pressure [closed]
It uses the difference between total pressure and static pressure, provided by the system, to either mechanically or electronically measure dynamic pressure. The dynamic pressure includes terms for ...
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Will two counter rotating vortices cancel each other?
Suppose that an aircraft flies with its wing through a tip vortex of another aircraft which flew in the opposite direction. Suppose that the shed wing tip vortex of both aircraft are exactly the same ...
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Making sailplane go faster
Sailplanes have much higher L/D than jetliners. But they are three times slower.
Is it practical to make a vanilla sailplane glide at 600mph by lifting it to a ridiculous altitude? If so, what would ...
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A Confusion about Digital DATCOM Calculations of a Tail Pitching Moment Coefficient
I'm using D DATCOM to estimate cm-alpha curve for a small tail planform with NACA-0012 airfoil using the namelist ($HTPLNF).
When taking the Tail planform aerodynamic center, ac (about 25% of MAC), as ...
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Why do the wings in these pictures go from swept back to parallel with the airflow? [duplicate]
To better understand my question, look at this A320 below
As you can see, the wing becomes parallel with the airflow at the wing root. Same thing on this 737
But this is not found on bigger planes ...
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Lifting-Line Theory - Numerical solution for a wing with dihedral angle
I'm trying to calculate lift for a wing with a dihedral angle using the Lifting-Line Theory. While using the thesis "Non-Planar Lifting-Line Theory for Fixed and Deformable Geometries" as a ...
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What happens to aerofoil downwash with Flaps extended vs retracted and how does it affect the Tail down force?
In my logic: Flaps extended will cause a greater Angle of Attack, to maintain Straight and Level Flight, AoA will be reduced, due to the increased "Surface", this allows to fly at lower ...
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