Journal of Aeronautics & Aerospace Engineering
Open Access

Aerodynamic Analysis

As is usual in aerodynamic analysis, for the purposes of obtaining simple expressions for the stability and control derivatives a wind axis reference system is assumed throughout. The choice of wind axes is convenient since it reduces the derivatives to their simplest possible description by retaining only the essential contributions and hence, maximises the visibility of the physical phenomena involved. It is therefore very important to remember that if the derivatives thus obtained are required for use in equations of motion referred to an alternative axis, then the appropriate axis transformation must be applied to the derivatives. Some useful transformations are given in Appendices 7 and 8Appendix 7Appendix 8. In all cases analytical expressions are obtained for the derivatives assuming subsonic flight conditions; it is then relatively straightforward to develop the expressions further to allow for the effects of Mach number as suggested in Section