Questions tagged [wing-sweep]

Angle of a line from root to tip, 25% of the way back from the leading edge, measured from the perpendicular to the longitudinal axis of the aircraft.

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76 views

How do I choose the correct params?

I am very new to airplane design. I am working on this project to design a flying wing glider (no propeller) that would glide in a circular pattern with a fixed radius of 250 m after being released at ...
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24 views

How do I factor sweep and dihedral in the lift equation?

I'm guessing that you add cos(angle of dihedral) to calculate lift loss by dihedral, but I'm not sure how to factor in the lift loss by the wing swept. Could someone help me include lift loss due to ...
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Why don't commercial aircraft have variable sweep wings? [duplicate]

I was wondering why commercial aircraft don't have variable sweep wings just like the Bell X-5 did? By sweeping the wing further at high altitude it helps the aircraft move faster and also it helps ...
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86 views

How does gust affect a swept wing

I have a basic question that I cannot seem to find a solid answer for: How does a gust affect a swept wing?
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What were the typical rotation and landing speeds of the X-29?

Looking online through all the available literature, I could not find the typical rotation ($V_r$), landing or even stall speed of the experimental forward swept wing X-29 aircraft. I'm curious to ...
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Expendable wingspan, long range early airplanes

Reading this question, I was wondering if, at some point early in aviation history there may have been airplane designs or concepts replacing or anticipating variable swept wing by "expendable ...
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1answer
168 views

Why does the effective alpha/CL increase at wingtip of swept wing?

If anybody could explain this in an intuitive way I'd really appreciate it. I haven't been able to find a clear answer on this. I understand that the increase in effective AoA/CL and the spanwise flow ...
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0answers
90 views

Would throttle steering of a forward-swept-winged aircraft be possible?

Fortunately (or perhaps unfortunately, given the number of crashes that had to occur for us to figure it out), the use of throttle manipulation to control an airliner with disabled primary flight ...
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2answers
272 views

Why does wing bending cause wingtip twisting?

(semanticscholar.org) When aft swept wings bend/flex, the outer wing is twisted leading edge (LE) down (this reduces wave drag), the reverse (LE up) is true for forward swept wings. I've searched ...
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Is some sweep beneficial with taper?

I'm developing a canard glider which requires some taper for the canard to stall first. I understand that sweep is typically only for aircraft in a compressible airflow (M >= 0.3), but is there any ...
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3answers
368 views

How is the change of moment handled in a Weight and Balance calculation with a swept wing aircraft?

I'm writing a weight and balance calculator for a charter operation. Every aircraft I've ever flight planned for has all the tanks on the same moment arm, so I don't know how you calculate the W&...
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3answers
328 views

How can the F-15 and Su-27 achieve a high top speed without variable wing geometry?

I watched a documentary once that explained, I believe, how the Su-27 and similar aircraft such as the F-15, can achieve a high top speed without variable wing geometry. How does this work? How do ...
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2answers
1k views

Straight Wings VS Delta Wings, Variable wing with Forward swept capability [duplicate]

What are the Pros and Cons (Advantages and Disadvantages) of a Delta wing and a Straight wing against each other, and if a Variable wing with a capability to become a Forward Swept wing is even ...
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1answer
1k views

Where is the wing sweep angle measured from?

If you look at a 747 planform wing you see something like this: In several aerodynamics and aircraft design text books they use the wing sweep angle as an important parameter to measure the wing ...
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2answers
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Why do some airplanes have simultaneously a straight wing and a swept horizontal stabilizer?

I'm sure there are many other examples like this one: Embraer EMB 120 with an almost straight wing and an obviously swept horizontal stabilizer. Why is there a difference in sweep angle between the ...
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254 views

Can the divergence Mach be greater than 1?

I know that by decreasing t/c and increasing the sweep angle it is possible to increase the divergence Mach, but what is the limit? I am calculating the Mach for a wing with a quarter chord sweep ...
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5answers
601 views

Is wing sweep needed on supersonic aircraft?

Area rule states that bodies with the same crossectional area distribution have the same drag. Does that mean I could use a straight wing on mach 1.2 aircraft with performance as high as sweep winged ...
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1answer
403 views

Spanwise flow and wingtip vortices in forward-swept wings

One of the benefits of forward-swept wing is that spanwise flow direction is from tip to root. However, in this answer an X-29 has quite significant sweep angle, at which drawbacks such as ...
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2answers
260 views

Why manufacturers does not producing variable sweep wing in our current scenario? [duplicate]

I read about many types of aircraft wing configurations like rectangular, swept forward, swept backword, and Delta wing. These configurations have their own advantages and disadvantages. But why we ...
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1answer
181 views

Why would lift coefficent change with weight on swept-wing aircraft?

Today I encountered a problem. There is a book saying, "Why does the lift coefficient of a swept-wing airplane decrease with the increase in the weight of the airplane?" I cannot think of the reason. ...
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1answer
2k views

How I determine numerically the roll rate of an aircraft?

I'm a Spanish student of aerospace engineering and I'm doing my final bachelor work that consists in designing an unlimited aerobatic plane, and I wonder if it is possible to calculate an ...
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2answers
276 views

Does wing sweep affect the direction of lift?

Given both a straight and swept wing (identical otherwise), exposed to the same airflow, would the direction of lift be the same? Please see below a crudely drawn example of my thinking. Additionally,...
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What aerodynamic characteristics arise from trailing edge sweep angle?

I drew 3 wing planforms, each with the same leading edge sweep. But they have different trailing edge sweep. Let's just assume for the moment that all those wings have the same surface area, so that ...
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1answer
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Why did the DC-3 have wing sweep?

When looking at the silhouette of a DC-3, one can clearly see that the wings are swept. This design is from 1935, before the high-speed research work on wing sweep was ever implemented, and the DC-3 ...
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3answers
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Why does the U-2 Dragon Lady not have swept wings?

Swept wings increase the critical mach number for aircraft with otherwise identical wings (Source 1). The U-2 Dragon Lady is limited in altitude by its critical mach number, as it needs more speed in ...
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Where is the spanwise flow? How does the span wise flow point the air towards the wingtip?

If you search Google for span wise flow, the first result under the pictures tab is a image of a wing with the span wise flow at the trailing edge: (Source) If you look at some other photos you ...
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1answer
855 views

Did the contemporaries of the F-14 also have automatic swing wings?

The F-14's Central Air Data Computer was a innovative design, using microprocessors for its implementation. This computer was used to control the swing wings of the F-14. How did the contemporary ...
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Why did the Avro Vulcan use a delta wing?

Why did the Avro Vulcan use a delta wing? The B52, from the same era, used a swept wing, and had a higher maximum speed. In the answer to What are the advantages and disadvantages of a delta wing ...
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2answers
496 views

Could a variable sweep aircraft also use negative angle?

Variable sweep on fighter aircraft is a bit out of fashion, but seems to a worthwhile option to adjust the wing to the current speed and needed lift. All this is bought with complexity and weight of ...
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1answer
1k views

How is a variable sweep wing constructed?

How is a variable sweep wing able to change its sweep?
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2answers
3k views

Why is the coefficient of drag for straight wings at supersonic speeds lower than for swept wings?

Why is the coefficient of drag of a straight wing lower than the coefficient of drag of a swept back wing at higher supersonic speeds (above, say, Mach 2)?
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What is the reason for the poor low-speed characteristics of sweptback wings?

I know there are advantages of swept-back wings delaying shock-wave allowing a aircraft to fly faster. However, what are the disadvantages. I know one of them is that they have very poor low speed ...
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3answers
7k views

What are the advantages and disadvantages of an oblique wing over a swing wing?

This question asks about the benefits of an oblique wing over a delta wing, but I am more interested in the benefits of an oblique wing compared to a swing wing. Wikipedia states: This is a ...
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1k views

What are the benefits of a pivot wing?

The answer to another question mentions the rather unusual pivot wing. From an aerodynamical standpoint, what are the benefits of an oblique wing compared to a delta, a trapezoid or a forward swept ...
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2answers
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Why should isobars be aligned with the leading edge of the main wing for a transonic cruiser?

When designing an airplane meant to cruise at transonic speeds (or supersonic speeds), I heard that one should look at the isobars on the main wing in order to assess if the shape, sweep angle and ...