+ case simpleSingleModel_flag:
+ {
+ /* simple model based on Hepperle's equation
+ * exponent dtdvvt was computed in uiuc_menu.cpp */
+ F_X_engine = Throttle[3] * t_v0 * (1 - pow((V_rel_wind/v_t0),dtdvvt));
+ F_Y_engine = 0.0;
+ F_Z_engine = 0.0;
+ M_l_engine = 0.0;
+ M_m_engine = 0.0;
+ M_n_engine = 0.0;
+ if (b_slipstreamEffects) {
+ tc = F_X_engine/(Dynamic_pressure * LS_PI * propDia * propDia / 4);
+ w_induced = 0.5 * V_rel_wind * (-1 + pow((1+tc),.5));
+ eta_q = (2* w_induced + V_rel_wind)*(2* w_induced + V_rel_wind)/(V_rel_wind * V_rel_wind);
+ /* add in a die-off function so that eta falls off w/ alfa and beta */
+ eta_q = Cos_alpha * Cos_alpha * Cos_beta * Cos_beta * eta_q;
+ /* determine the eta_q values for the respective coefficients */
+ if (eta_q_Cm_q_fac) {eta_q_Cm_q *= eta_q * eta_q_Cm_q_fac;}
+ if (eta_q_Cm_adot_fac) {eta_q_Cm_adot *= eta_q * eta_q_Cm_adot_fac;}
+ if (eta_q_Cmfade_fac) {eta_q_Cmfade *= eta_q * eta_q_Cmfade_fac;}
+ if (eta_q_Cm_de_fac) {eta_q_Cm_de *= eta_q * eta_q_Cm_de_fac;}
+ if (eta_q_Cl_beta_fac) {eta_q_Cl_beta *= eta_q * eta_q_Cl_beta_fac;}
+ if (eta_q_Cl_p_fac) {eta_q_Cl_p *= eta_q * eta_q_Cl_p_fac;}
+ if (eta_q_Cl_r_fac) {eta_q_Cl_r *= eta_q * eta_q_Cl_r_fac;}
+ if (eta_q_Cl_dr_fac) {eta_q_Cl_dr *= eta_q * eta_q_Cl_dr_fac;}
+ if (eta_q_CY_beta_fac) {eta_q_CY_beta *= eta_q * eta_q_CY_beta_fac;}
+ if (eta_q_CY_p_fac) {eta_q_CY_p *= eta_q * eta_q_CY_p_fac;}
+ if (eta_q_CY_r_fac) {eta_q_CY_r *= eta_q * eta_q_CY_r_fac;}
+ if (eta_q_CY_dr_fac) {eta_q_CY_dr *= eta_q * eta_q_CY_dr_fac;}
+ if (eta_q_Cn_beta_fac) {eta_q_Cn_beta *= eta_q * eta_q_Cn_beta_fac;}
+ if (eta_q_Cn_p_fac) {eta_q_Cn_p *= eta_q * eta_q_Cn_p_fac;}
+ if (eta_q_Cn_r_fac) {eta_q_Cn_r *= eta_q * eta_q_Cn_r_fac;}
+ if (eta_q_Cn_dr_fac) {eta_q_Cn_dr *= eta_q * eta_q_Cn_dr_fac;}
+ }
+ /* Need engineOmega for gyroscopic moments */
+ engineOmega = minOmega + Throttle[3] * (maxOmega - minOmega);
+ break;
+ }