A compound airtable groups together a number of airfoil tables. Consider, for instance, an airfoil with a trailing edge flap. For a given angular deflection of the flap, δ1, an airtable is provided that lists the lift, drag, pitching moment, and hinge moment coefficients. Of course, for a different angular deflection of the flap, δ2, a new airtable must be provided. Such a compound airfoil table can be defined as follows.
It implies that airtables AirTableName1 or AirTableName2 will be used if the flap deflections are δ1 or δ2, respectively. For flap deflection δ1 < δ < δ2, linear interpolation will be used to compute the aerodynamic coefficient, c,
c = [δ2 c1 - δ1 c2 + δ(c2 - c1)]/(δ2 - δ1),
where c1 and c2 are the aerodynamic coefficients interpolated in airtables AirTableName1 and AirTableName2, respectively. The same formula is used for interpolation of the lift, drag, pitching moment, and hinge moment coefficients.
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