This wiki is currently experiencing migration problems. This is known and will be fixed at some point.

Registered users can edit this wiki.

Wing

From Kerbal Space Program Wiki
Jump to: navigation, search

A wing is a type of part primarily used to provide lift during horizontal flight inside an atmosphere. Wings are the defining feature of planes, though wings may enable short-term flying or gliding by rovers and other craft. The lifting forces they generate can also be used in novel ways.

The lift generated depends on the local density of atmosphere, the square of the relative speed, and the wings' angle of attack (AoA). The atmospheric density and relative velocity squared generate the aerodynamic force called dynamic pressure (Q) according to the following formula:

Q=0.5\,\cdot \rho \,\cdot v^{2}\,
Where:
  • \rho the local density of the atmosphere [kg/m³]
  • v the speed of the craft relative to the atmosphere [m/s]

The three-dimensional point where lift from all wings, winglets, and control surfaces averages out is the center of lift, which in rough terms acts like a lever with the fulcrum being the center of mass. The relative position of the center of lift to mass is the decisive element for an aircraft's or a rocket's stability. If the center of lift is front of the center of the mass, the craft will be instable - the deflection causes forces further increasing the deflection. If the center of mass is front of the center of the lift, the craft will be instable - the deflection causes forces decreasing the deflection, turning the craft to the heading direction - the effect increases by the distance between the two point. The stability means the nose of the craft spontaneously pointing towards the prograde direction, following the ballistic trajectory. The winglets of the ballistic rocket must be placed on the bottom of the rocket, but the planes' center of the center of lift can be only a bit behind the center of the mass, as the wings need some angle of attack for generating lift. This means the center of lift placed too rear causes stabilizing torque - virtually pushing the nose down as following the ballistic trajectory, which cannot be surpassed by torque generated by the control surfaces.

Wings generate drag as an inherent consequence of generating lift. As drag decreases the speed of the aircraft, some kind of engine is needed for propulsion, or its initial kinetic and potential energy will be consumed in a gliding maneuver. The generated lift greatly depends on the angle of attack. The lift increases with the AoA in an interval, but at greater angles the drag increases more rapidly than the lift, decreasing the efficiency of the wing. The optimal angle of attack is that with the highest L/D (lift/drag) ratio.

By themselves, wings provide no steering control, though their lifting forces will impact movement of a craft in flight. The trailing edges are often an ideal place for attaching control surfaces.

List of wings

Modular wings

The dimensions of the modular wings are specified below using this format. The edge of the wing that connects to a root part is located on the right in this image.

A number of the wing parts are modular: they strictly follow a standardized geometry, and as a result of this they are easy to connect to each other without gaps and holes. This property makes the design of custom wing configurations easy. However, due to the tree structure of craft, the connections between these parts in larger wing structures can become unstable, and may have to be strengthened with strut connectors.

The notation for the wing dimensions used in the table below is as follows:

  • L [Length] - total length of the wing module
  • W [Width] - the dimension of the edge of the wing module at its root connection
  • E [End] - the dimension of the edge of the wing module at the side opposite to the root connection (for wing modules with a constant chord, E=W; for triangular wing modules, E=0).
  • SD [Sweeping Depth] - depth of the sweeping-back of the wing: the distance between the opposite ends of the rear edge along the axis of the W dimension (for wing modules with a trailing edge perpendicular to W, SD=0)


Dimensions (m)
Image Part Radial size Cost
(Fund)
Mass
(t)
Max. Temp.
(K)
Tolerance
(m/s)
Tolerance
(g)
Lift L W (/ E) SD
Wing Connector Type A.png
Wing Connector Type A Radial mounted 500 0.2 2 400 15 50 2 2 4
Wing Connector Type B.png
Wing Connector Type B Radial mounted 500 0.2 2 400 15 50 2 4 2
Wing Connector Type C.png
Wing Connector Type C Radial mounted 250 0.1 2 400 15 50 1 2 2
Wing Connector Type D.png
Wing Connector Type D Radial mounted 100 0.05 2 400 15 50 0.5 2 1
Wing Connector Type E.png
Wing Connector Type E Radial mounted 100 0.05 2 400 15 50 0.5 1 2
Delta wing.png
Delta Wing Radial mounted 600 0.2 2 400 15 50 2 4 4 / 0
Small Delta Wing.png
Small Delta Wing Radial mounted 200 0.05 2 400 15 50 0.5 2 2 / 0
Wing Strake.png
Wing Strake Radial mounted 400 0.05 2 400 15 50 0.5 1 4 / 0
Structural Wing Type A.png
Structural Wing Type A Radial mounted 500 0.1 2 400 15 50 1 2 4 / 0
Structural Wing Type B.png
Structural Wing Type B Radial mounted 500 0.1 2 400 15 50 1 4 2 / 0
Structural Wing Type C.png
Structural Wing Type C Radial mounted 300 0.05 2 400 15 50 0.5 4 1 / 0
Structural Wing Type D.png
Structural Wing Type D Radial mounted 150 0.025 2 400 15 50 0.25 1 2 / 0
Swept Wing Type A.png
Swept Wing Type A Radial mounted 500 0.113 2 400 15 50 1.13 4 2 / 0 2
Swept Wing Type B.png
Swept Wing Type B Radial mounted 500 0.226 2 400 15 50 2.26 4 2 / 2 2


Irregular wings

Irregular wings have varied geometry, and are generally not intended to be connected to one another.

Image Part Cost
(Fund)
Mass
(t)
Max. Temp.
(K)
Tolerance
(m/s)
Lift
BasicFin.png
Basic Fin 25 0.01 934 4 0.12
AVT1 Winglet.png
AV-T1 Winglet 500 0.04 2 000 12 0.3
Tail fin.png
Tail Fin 600 0.13 2 000 12 0.61
Swept wings.png Swept Wings 620 0.275 2 000 15 1.37
FAT455AirplaneWing.png
FAT-455 Aeroplane Main Wing[Note 1] 2 800
(2 320)
3.78
(0.78)
2 000 15 7.8
BigSWingStrake.png
Big-S Wing Strake[Note 1] 1 000
(920)
0.6
(0.1)
2 000 15 1.0
BigSDeltaWing.png
Big-S Delta Wing[Note 1] 3 000
(2 760)
2.0
(0.5)
2 000 15 5.0
  1. 1.0 1.1 1.2 The FAT-455 Aeroplane Main Wing, Big-S Wing Strake, and Big-S Delta Wing are a combination of lifting surface and liquid fuel tank. Only the lift properties are shown.