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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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Could Falcon 9 fairing become glidable / flyable?

Reading and thinking about this and this questions on space exploration stackexchange, I was wondering if the fairing could shape itself, so that it becomes one stable and steerable gliding element ...
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Are there any airplanes with the Centre of Gravity behind the Centre of Pressure?

We are used to seeing a forward CG in all airplanes, from a small Cessna to a large Boeing. I wonder whether any airplane with CG behind wing CP exists in production? Is it even possible? If so, what ...
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Air flow over an airfoil

We know that in real viscous flow, boundary layer exists around the airfoil and there will be a separation point which flow starts to separate from the back of the airfoil( velocity gradient equal ...
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How to calculate the power required during transition from VTOL to fixed wing?

In a VTOL, I have calculated the power required for take off and cruise which was not difficult at all. Between take off and cruise, there is a phase where the VTOL has to transition by tilting the ...
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What is subcritical and supercritical boundary layer?

What is subcritical and supercritical boundary layer? What is the difference between them?
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Can the ball on a turn coordinator be to the full right/left while the wings are level?

Can it ever happen in a wings level flight that the Turn and Slip indicator ball is to the full right/left? If so then when and what will be the flight path of such an aircraft? Thanks in advance.
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Would a propeller extracting air from a cylinder with holes in it be an ideal lift apparatus for a VTOL aircraft?

I am wondering if enough lift can be created for a VTOL aircraft using a propeller that is extracting air from a cylinder which is closed at one end and has holes in the top half of the cylinder. ...
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Was the Space Shuttle aerodynamically neutral while piggybacking, or did the combination act like a giant biplane?

Trying to investigate this question, I see that 'Ask the Captain' says: The weight of the shuttle is calculated like any payload. The 747 produces enough lift to fly and to carry the weight of ...
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How can I calculate the velocity of air drawn by a pusher configured propeller?

I am attempting to construct a model plane using Custer channel wings. In order to calculate (or at least approximate) the lift generated I need to find the speed of the air through the channel due to ...
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How are these parameters derived from readings of sensors in an aircraft: angle of attack, slip angle, and airspeed?

From what I've learned, the reading comes from an angle of attack sensor and a slip angle sensor. Let's call the readings $\hat\alpha$ and $\hat\beta$ respectively. These are of either the ...
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Why does an aircraft's nose tend to pitch downward at higher bank angles?

In the usual aircraft configuration, the center of lift is located behind the CG producing negative pitch moment (the horizontal stabilizer counteracts it by producing downforce - positive pitching ...
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Force Balance in Wind Tunnel

I am considering a model wing inside a wind tunnel supported from underneath from its center of mass. Two load cells can be used, when properly oriented, to measure the lift force and the drag force. ...
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Wing Shape: Long/Wide Span Wings vs Deep Wings [duplicate]

Planes use wings to generate lift. The wider the span of the wing (looking at the plane from the front) the more lift it generates, however, this is at the expense of more drag. Some planes like the ...
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What is a rudder or fin stall?

What is a rudder or fin stall, how will the aircraft behave in that situation, and how should the pilot recognise it? What is the recovery procedure? And what is rudder reversal?
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Is the Meredith effect utilized in the cowling design of air-cooled engines?

The P-51 is famous for its advanced-for-its-time aerodynamics, the prime example of which is the radiator design under the belly which utilizes the Meredith effect to, in effect, turn it into a mini ...
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Why is the 737’s aileron/spoiler authority reduced at low flap settings?

According to the NTSB report on the crash of United Airlines Flight 585, the ability of the 737’s lateral controls (ailerons and flight spoilers) to counteract the rolling forces produced by (say) a ...
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What elements are required for an airplane to generate lift? [duplicate]

I'm not a scientist but what basic things does a plane need to get lift? Does it have to do with the flow of air produced by the shape of the wing as the plane moves forward on the runway? What would ...
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Why does the rotor thrust decrease at smaller tip clearance for shrouded rotor?

Consider this system, rotor with shroud: From this research, we see that: at the same rpm, the rotor thrust decreases,the shroud thrust increases as tip clearance decreases. But why does the rotor ...
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What is the glide ratio on the CE-S550 Citation S-II?

I couldn't find it in the AFM. Is it different then the square winged citation II?
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Does rolling or yawing affect the angle of attack?

If I'm on final in windy conditions and I need excessive rolling and yawing movements to stay on centerline and say, my pitch stays constant - does rolling or yawing change my AOA such that I could ...
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Why does elevator input move the turn coordinator ball in steep turns?

When practicing steep turns, I'm running into an unusual phenomenon. If the airplane is losing altitude in coordinated flight and I apply aft stick pressure to pitch up and correct, I notice that the ...
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Where am I wrong at aerodynamic center calculation?

I'm currently taking aerodynmics course.In the classical thin airfoil theory. we saw that both for symmetric and non-symmetric airfoils the term $dc_l/d\alpha= 2\pi$. But in the preceding chapter, ...
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How do split winglets reduce bending moment in the wings?

I am doing a study on split winglets and how they are more advantageous than blended winglets . While browsing through the net, I was reading an article about the Boeing 787 Dreamliner and they had ...
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Did the airfoil choice on the P51D affect its maneuverability? [closed]

Did the wing design on the P51D, which used a laminar airfoil, affect its maneuverability? If so, how? To what extent?
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Where can I find complete aircraft blueprints for the purpose of study?

Where can I find aircraft blueprints for the purpose of study? I find that I learn a lot more when I am able to get the big picture of a machine that is used in real life (for example, to understand ...
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What causes the adverse pressure gradient that leads to flow separation?

When reading about flow separation I generally see a diagram like this: imp source: Wikimedia commons This shows that the boundary layer slows as it passes over the wing, eventually creating an ...
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Is it reasonable for flight economy to correct banking tendencies with stick and rudder?

An aircraft with side-by-side seating but only one person aboard should fly banked. Banking decreases lift and more elevator is needed than in leveled flight which increases drag. Correcting the ...
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What is the most efficient symmetrical airfoil shape?

What is the most efficient symmetrical airfoil shape to make for a covering for a round upright bar that measures 40mm outside diameter? The speed of travel will be 25Kph and I also need a shape to ...
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Is there any evidence that the downwash vortices impact the performance of a wing?

Or is it merely flow separation on the upper surface towards the end of the wing? The assumption seems to be that the air "leaks" from under the wing to low pressure above with sufficient rapidity to ...
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Wing pitching moment decomposition into two terms

Summary: Assuming constant angle of attack $\alpha$, speed $V$, and lift $L$ applied at the center of pressure CP (whose position is $x_{CP}$), the distance $(x_{CP} - x_O)$ between the moment ...
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Where can you find wind tunnel visualization data online?

I was wondering if there was a repository of flow visualization results somewhere online, preferably of wing sections categorised in some manner.
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How does the power requirement change when weight and speed change?

Suppose I have an airplane with a certain weight M, which uses a certain amount of power P, to fly at a certain speed V. If I use the same airplane, but quadruple the weight (4xM) and double the ...
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Where should the support points be for testing a model wing in a wind tunnel?

When testing a certain wing profile inside a wind tunnel where should the model, small scale wing be supported? Should the support be under the center of mass of the wing or under the aerodynamic ...
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Pressure Distribution Pattern around Wing

it is clear that the overall integrated pressure on the top of the wing is less than the overall pressure at the bottom of a wing in order to produce a net nonzero lift force. Based on the attached ...
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Could a moving film of gas reduce aerodynamic drag?

https://en.m.wikipedia.org/wiki/File:Coanda_effect_6.jpg In the image linked there is depicted a system which creates, using the Coandă effect, a film of gas traveling along the surface of a body. If ...
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Would an F-15 or similar stand in be able to continue flight at high speed if it lost its canopy?

Let's say for whatever reason, miscued ejection system perhaps, a jet in flight at exactly mach 1 blew its canopy but did not eject the pilot. And we can assume the altitude is fairly low (to exclude ...
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Aerodynamics and fuel consumption of a powered glider

I want to optimize the flight distance of a powered glider model airplane, without the use of soaring. I've studied some aerodynamics books, but still feel unsure about my conclusions. Please tell me ...
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How does wing aspect ratio influence lift and drag?

I know simmilar questions are all over the internet (and this website too), but there's one thing that i just cannot comprehend and none of the articles i read could explain it properly. According to ...
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Could an airplane takeoff with a very strong tailwind if its propeller blades are set to a negative pitch? [closed]

Would it be possible for an airplane to accelerate and takeoff with a very strong tailwind if its propeller blades are set to a negative pitch? For example, let's say that a hurricane was approaching ...
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Determine “basic lift distribution” over a wing that has a circulation distribution

I don't understand what they mean with basic lift distribution. I have calculated C_L which is 5a (a is alpha in radians). I added the relevant equations here.
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How do endplates reduce induced drag?

I have heard the explanation which states that the endplates reduce the tip vortex formation thereby reducing induced drag. From what I understand induced drag is the backwards component of the total ...
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Fabric-covered Clark Y Max Coefficient of Lift

I'm looking at the Aeronca C-3 Collegian, which had a Clark Y airfoil, and I'm finding the following: Wing area: 142 ft² Empty weight: 466 lbs Payload: 470 lbs Stall speed: 38 mph When I do the math ...
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When calculating lift, using the the NASA lift equation, can any value be increased, ie. velocity or surface area, for increased lift?

I am trying to understand the breakdown of the NASA lift formula, which is written as such $L = C_L \frac{\rho v^2}{2}A$ If I take for example CL=0.87, v=20m/s, ρ=1.22kg/m3, and A=9.02m2, my ...
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Does a Stalled Wing Exhibit No Circulation

If a wing is stalled, will the wing not exhibit any circulation as predicted by the Kutta-Joukowski theorem? If so how would this affect the pressure distribution between the top and bottom portions ...
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What was the Airfoil of Handley Page P.115?

This extreme sweptback delta was built to test the Concorde wing at low speeds, sources say it had a biconv 6% airfoil, but I failed in finding data about it.
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What is the relationship between drag and sink rate?

I was just brushing up on basic aerodynamics and I have something I want to clarify about flying in the region of reverse command. I went up in my 172 the other day and noticed the following while ...
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What was the lift equation used by the Wright brothers?

NOTICE: The modern lift equation and the lift equation used by the Wright brothers in 1900 are slightly different. The lift coefficient of the modern equation is referenced to the dynamic pressure ...
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Is it possible to make an analogy between a lever and an airplane wing in terms of force applied over distance?

On most aircraft the engine force (thrust) is lower than the weight. Since wings therefore are always capable of generating greater force (lift) than the engine, there is an analogy between an ...
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Aerodynamics moment of a wing

An old flight book that I am reading discusses the aerodynamic moment about a wing and talks about an upper and lower lifts. I can see how the pressure distribution on the top surface produces an ...
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How does Bernoulli's principle contribute in lifting airplane?

I have searched if any explanation that bind Bernoulli's principle in lifting airplane. There is one here which receive many appreciations, but still did not answer the question. So far, it was taught,...