MISSILE AERODYNAMIC DERIVATIVES

TABLE 4.8

Missile Derivatives in a Linear Model

Подпись: AOA (Pitch) b (Yaw) Fin Deflection/Pitch Yaw Roll де DU DU DU DU Da Db D8e D8r D8„ Df Df Df Df Df Da Db D8e D8r D8a д f Df Df Df Df Da Db D8e D8r D8a Daz Daz Daz Daz Daz Da Db D8e D8r D8a Dax Dax Dax Dax Dax Da Db D8e D8r D8a Day Day Day Day Day Da Db D8e D8r D8a Source: Driscoll, T.R. et al., Determination of aerodynamic coupling derivatives through flight test, AIAA Guidance and Control Conference, Boston, Massachusetts, USA, 20-22 August, 1975. Changes in Variables

Pitch angular acceleration

Roll angular acceleration Yaw angular acceleration Normal (pitch) acceleration, az Axial acceleration, ax Yaw acceleration, ay

by mass m and the moment derivatives are divided by respective moment of inertia. A complete linear derivative model of a missile could have 30 derivatives [9] as shown in Table 4.8.

Подпись: (4.35)

Interestingly these derivatives of Table 4.8 are called acceleration derivatives. The reason will be clear from the following development:

8U _ pU2Sc 8a 2Iy ‘

Подпись: Ma
Подпись: 1 @M _ PU2Sq dCm _ 8U Iy da 2Iy da 8 a Подпись: (4.36)

We know from Equation 4.7 that

Hence, 8a = Ma and we see that the corresponding derivative is also called pitch angular acceleration derivative. Similarly, all other derivatives of Table 4.8 can be shown equivalent in their formats by their definitions to aircraft derivatives. Some additional derivatives seem to have been defined in the case of a missile as can be seen from the Table 4.8, as compared to aircraft.