aeroPerformanceMapType

Aerodynamic coefficients of the complete aircraft over altitude, Mach number, sideslip angle and angle of attack. The force and moment coefficients are given in the aerodynamic coordinate system, i.e. along and about the axes d, s and l, which follow the free stream. Their directions and signs are defined in section 4.2 of cpacsType.

Coefficients

The force coefficients <cd>, <cs> and <cl> are the components of the resulting aerodynamic force F along the axes d, s and l, divided by the dynamic pressure of the free stream and the reference area S. The moment coefficients <cmd>, <cms> and <cml> are the components of the resulting moment M about the moment reference point, divided in addition by the reference length l:

S, l and the moment reference point are the reference values of the model (.../model/reference/area, .../model/reference/length and .../model/reference/point, see referenceType). There is only one reference length, typically the mean aerodynamic chord, and it normalizes all three moment coefficients, the rolling and the yawing moment included. The moment reference point is fixed; a tool that needs the moments about the center of gravity transfers them to the current center of gravity itself.

Map

The parameters <altitude>, <machNumber>, <angleOfSideslip> and <angleOfAttack> are vectors of equal length, and the entries with the same index form one point of the map. The coefficients and the damping derivatives are vectors of the same length, holding the values at these points.

The example shows the map of a short-range airliner at low speed with five angles of attack at the sideslip angles 0° and 4°; the reference area is 129.58 m², the reference length 4.225 m, and the moment reference point lies at the leading edge of the mean aerodynamic chord. At the fourth point (α = 4°, β = 0°), the lift coefficient is 0.5672 and the drag coefficient 0.0365. At β = 4°, the free stream comes from the right: the side force points to the left (<cs> < 0), the right wing is lifted (<cmd> > 0) and the nose turns to the right into the wind (<cml> < 0).

<altitude>1200;1200;1200;1200;1200;1200;1200;1200;1200;1200</altitude>
<machNumber>0.2;0.2;0.2;0.2;0.2;0.2;0.2;0.2;0.2;0.2</machNumber>
<angleOfSideslip>0;0;0;0;0;4;4;4;4;4</angleOfSideslip>
<angleOfAttack>-2;0;2;4;6;-2;0;2;4;6</angleOfAttack>
<cd>0.0221;0.0241;0.0289;0.0365;0.0468;0.0235;0.0256;0.0304;0.0379;0.0482</cd>
<cs>0;0;0;0;0;-0.0628;-0.0628;-0.0628;-0.0628;-0.0628</cs>
<cl>0.0436;0.2182;0.3927;0.5672;0.7418;0.0436;0.2182;0.3927;0.5672;0.7418</cl>
<cmd>0;0;0;0;0;0.0559;0.0559;0.0559;0.0559;0.0559</cmd>
<cms>0.0804;0.0018;-0.0767;-0.1553;-0.2338;0.0804;0.0018;-0.0767;-0.1553;-0.2338</cms>
<cml>0;0;0;0;0;-0.0698;-0.0698;-0.0698;-0.0698;-0.0698</cml>