+ F_X_aero = CX * qS;
+ F_Y_aero = CY * qS;
+ F_Z_aero = CZ * qS;
+ }
+ else
+ {
+ // Cos_beta * Cos_beta corrects V_rel_wind to get normal q onto wing,
+ // hence Cos_beta * Cos_beta term included.
+ // Same thing is done w/ moments below.
+ // Without this "die-off" function, lift would be produced in a 90 deg sideslip, when
+ // that should not be the case. See FGFS notes 021105
+ F_X_wind = -CD * qS * Cos_beta * Cos_beta;
+ F_Y_wind = CY * qS;
+ F_Z_wind = -CL * qS * Cos_beta * Cos_beta;
+ // F_X_wind = -CD * qS * Cos_beta * Cos_beta;
+ // F_Y_wind = CY * qS * Cos_beta * Cos_beta;
+ // F_Z_wind = -CL * qS * Cos_beta * Cos_beta;
+
+ // wind-axis to body-axis transformation
+ F_X_aero = F_X_wind * Cos_alpha * Cos_beta - F_Y_wind * Cos_alpha * Sin_beta - F_Z_wind * Sin_alpha;
+ F_Y_aero = F_X_wind * Sin_beta + F_Y_wind * Cos_beta;
+ F_Z_aero = F_X_wind * Sin_alpha * Cos_beta - F_Y_wind * Sin_alpha * Sin_beta + F_Z_wind * Cos_alpha;
+ }
+ // Moment calculations
+ M_l_aero = Cl * qSb ;
+ M_m_aero = Cm * qScbar * Cos_beta * Cos_beta;
+ M_n_aero = Cn * qSb ;
+ // M_l_aero = Cl * qSb * Cos_beta * Cos_beta;
+ // M_m_aero = Cm * qScbar * Cos_beta * Cos_beta;
+ // M_n_aero = Cn * qSb * Cos_beta * Cos_beta;
+
+ // Adding in apparent mass effects
+ if (Mass_appMass_ratio)
+ F_Z_aero += -(Mass_appMass_ratio * Mass) * W_dot_body;
+ if (I_xx_appMass_ratio)
+ M_l_aero += -(I_xx_appMass_ratio * I_xx) * P_dot_body;
+ if (I_yy_appMass_ratio)
+ M_m_aero += -(I_yy_appMass_ratio * I_yy) * Q_dot_body;
+ if (I_zz_appMass_ratio)
+ M_n_aero += -(I_zz_appMass_ratio * I_zz) * R_dot_body;
+
+ if (Mass_appMass)
+ F_Z_aero += -Mass_appMass * W_dot_body;
+ if (I_xx_appMass)
+ M_l_aero += -I_xx_appMass * P_dot_body;
+ if (I_yy_appMass)
+ M_m_aero += -I_yy_appMass * Q_dot_body;
+ if (I_zz_appMass)
+ M_n_aero += -I_zz_appMass * R_dot_body;
+
+ // gyroscopic moments
+ // engineOmega is positive when rotation is ccw when viewed from the front
+ if (gyroForce_Q_body)
+ M_n_aero += polarInertia * engineOmega * Q_body;
+ if (gyroForce_R_body)
+ M_m_aero += -polarInertia * engineOmega * R_body;
+
+ // ornithopter support
+ if (flapper_model)
+ {
+ uiuc_get_flapper(dt);
+ F_X_aero += F_X_aero_flapper;
+ F_Z_aero += F_Z_aero_flapper;
+ M_m_aero += flapper_Moment;