New answers tagged

0

Why are fuel tanks located in wings? Because it is hard to fit the passengers or their baggage into the wings.


1

Assuming that both props are rotating clockwise as seem from the rear, the orientation of the exhaust pipes makes sense if the goal is to ensure that the exhaust gasses are kept clear of the wing. The rotating propwash will tend to carry the exhaust from the right-side pipe (in rear view) of each engine well below the wing. If the left-side exhaust pipes ...


5

One big reason is to make room for external stores such as fuel, weapons and electronics packs. A low-wing design must have longer and therefore heavier and bulkier undercarriage if ground access to the underwing hard points is to be adequate. Also, the upper surface of a high wing is larger and cleaner, providing better lift over the fuselage and reducing ...


2

Trapezoidal wings have advantages and disadvantages: Better performance than delta wings at transonic speed Good stealth performances Flaps can be easily used. drag reducing better Lift/Drag ratio than delta wings The problem is that they stall at much lower angles of attack than delta wings. Edit:this problem is overcome using leading edge,LERX,and/or ...


1

The first aeroplane to be certified inherently stable, the Dunne D.5 of 1910, had a tailless swept wing. A series of biplanes and monoplanes followed, all tailless swept types and some arguably flying wings with bits dangling off. The key feature which made them stable in pitch was twisting down or washing-out the wing from root to tip, later described as "...


5

Vertical bolt = less optimal. The reason is the tube walls in the 12:00 and 6:00 locations (top and bottom areas) are effectively the primary tension and compression members of the tube, and the 9 - 3:00 areas are the shear zones. In other words, if the tube was an I beam, you'd be putting holes right in the cap strip flange of the I beam where the tension ...


6

For the same wing span, an elliptical wing planform is the most aerodynamically efficient compared to any other flat wing planform because it has the lowest induced drag. Note that we are comparing only aerodynamics here. Things get much more nuanced once you couple structural weights, stability & control for a global efficiency (also see @Peter's answer)...


5

The inefficiency is the result of a comparably high weight in relation to the possible lift. However, for small aircraft that disadvantage is not very pronounced (this is true especially for braced wings and biplanes) and is outweighed by very favorable stall characteristics. Also, a rectangular wing is very easy to build. Compare with what has been built so ...


2

The fundamental issue is the behaviour at the wing tip. On a rectangular wing the high pressure beneath and the low pressure above cause air to spill up round the tip and spiral backwards in a wingtip vortex. This both lowers the pressure difference, reducing lift near the tip, and loses energy to the vortex, increasing drag. Both these effects reduce ...


4

Short answer: Yes. Maximum speed is correlated with wing loading. A high wing loading shifts all speeds up. A flying wing will always have a lower wing loading in comparison to a conventional design when payload, range and landing speed of both are identical. So you will start at a disadvantage. Due to the high lever arm of the conventional tail, the ...


0

Your question has been at issue ever since the early pioneer days of flight. British pioneer J.W. Dunne discovered the principle around 1905-6 and developed a tailless swept monoplane with drooped and washed-out wingtips. He used their negative lift to provide lateral as well as longitudinal stability. He patented it in 1909 (UK pat. 08118), got it flying as ...


0

Twisting the wing tips to a lower angle of attack helps create an "elliptical" lift distribution, which reduces stress loads on the wing the farthest away from the wing root. However, if one ever watches the take-off roll of the Rutan Voyager, one can see the dangers of this design combined with a tricycle landing gear. In this (extreme) case, the wing ...


2

To add to the other answers, a stiff wing is a heavy wing. If flex can be permitted then the wing can be made lighter. Flex does increase the risks of things like fatigue cracking (metal), delamination (composite), excessive strain and aerodynamic surprises, but if these are all allowed for in the design then the plane will be lighter and have a better ...


3

From Mason’s Perspective on the X-29: The other issue with this airfoil is that every Grumman aerodynamicist felt the need to “improve” it, so that there were many variations. I think the airfoil that was used on the X-29 was known as K-Mod 2. I’m not sure anybody can say with certainty what the actual airfoil coordinates are. Grumman was not good with ...


0

To include the point force from the engine mount you will need to use a Dirac delta and a Heaviside step function to add in the moment caused by the engine. The Dirac delta multiplied by the engine weight will model the force, and once you integrate over the span once to obtain the moments it naturally will turn into the Heaviside step function.


2

The 737 has quite a complicated tracked mechanism to deploy its Fowler flaps. I think it's designed to allow all elements of the flaps to move parallel to each other, as opposed to perpendicular to the trailing edge. That prevents the flaps from jamming into each other at the inside corner. The 787, on the other hand, has quite simple dropped hinged flaps. ...


Top 50 recent answers are included