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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Airplane speed retention question? [closed]
Imagine the scenario when a plane is flying, then it turns off its engine and nose dives. After gaining a lot of speed, if the pilot pulls the stick back and the plane now points upwards again, will ...
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Why total drag formula include drag at zero lift?
Total drag = Do + DL
Why total drag include drag at zero lift if we are interested at drag when wing produce lift?
We cant assume that friciton and particularly pressure drag at zero lift AoA dont ...
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Does induced drag drop when wing is stalled?
From formula, induced drag is function of lift. When wing stalls, lift is reduced so induced drag must also be reduced?
Stall decrease static pressure at suction side of wing, so I know pressure drag ...
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Would shockwave over a Supercritical aerofoil move downstream with Angle of attack? [duplicate]
over a supercritical aerofoil, would a shockwave move downstream with increase in angle of attack?
I thought yes as the top surface is flat?
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What does this part on a vertical stabilizer do? [duplicate]
On a B787 vertical stabilizer shown in the image, there's this small fin at the leading edge that connects to the fuselage.
It seems too small in size to be considered a dorsal fin. Simply adding this ...
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Why does minimum pressure point move towards leading edge with aoa?
why is it that the minimum pressure peak over the top surface moves towards the front of the aerofoil with angle of attack increase?
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Sources for Aircraft Glide Ratio
I would like to gather data on the best glide ratio of different commercial aircraft. Unfortunately, it has proven non-trivial to obtain data aside from a few lucky examples.
Eurocontrol's BADA gives $...
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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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Do vortex generators increase lift even at low AoAs?
Does wing produce higher lift with VGs even at low AoAs(let say 10°) compare with wing without VGs?
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Oswalds efficiency factor for trapezoidal wing
For a part of my university project we have to approximate 2d to 3d data ideally using oswalds efficiency factor, the equations given to us are for either rectangular or swept wings however the wing I ...
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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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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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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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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 does a wing's pitching moment distribution tend towards zero at the tip instead of towards cm0?
I am currently playing around with XFLR5 and am trying to wrap my head around the following:
For airfoils, my understanding that the pitching moment has a component that is independent of lift, which ...
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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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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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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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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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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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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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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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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 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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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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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 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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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 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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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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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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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 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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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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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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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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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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