diff --git a/trunk/SUAVE/Analyses/Stability/Fidelity_Zero.py b/trunk/SUAVE/Analyses/Stability/Fidelity_Zero.py index 555761e899..99667c1f99 100644 --- a/trunk/SUAVE/Analyses/Stability/Fidelity_Zero.py +++ b/trunk/SUAVE/Analyses/Stability/Fidelity_Zero.py @@ -185,7 +185,8 @@ def __call__(self,conditions): # Derivative of pitching moment with respect to pitch rate l_t = geometry.wings['horizontal_stabilizer'].origin[0][0] + geometry.wings['horizontal_stabilizer'].aerodynamic_center[0] - geometry.wings['main_wing'].origin[0][0] - geometry.wings['main_wing'].aerodynamic_center[0] #Need to check this is the length of the horizontal tail moment arm - stability.static.Cm_q = Supporting_Functions.cm_q(conditions.lift_curve_slope, l_t,mac) # Need to check Cm_i versus Cm_alpha + vht = geometry.wings['horizontal_stabilizer'].areas.reference * l_t / (geometry.reference_area*geometry.wings['main_wing'].chords.mean_aerodynamic) + stability.static.Cm_q = Supporting_Functions.cm_q(conditions.lift_curve_slope, vht, l_t,mac) # Need to check Cm_i versus Cm_alpha # Derivative of pitching rate with respect to d(alpha)/d(t) stability.static.Cm_alpha_dot = Supporting_Functions.cm_alphadot(stability.static.Cm_alpha, geometry.wings['horizontal_stabilizer'].ep_alpha, l_t, mac) # Need to check Cm_i versus Cm_alpha diff --git a/trunk/SUAVE/Methods/Flight_Dynamics/Dynamic_Stability/Full_Linearized_Equations/Supporting_Functions/cm_q.py b/trunk/SUAVE/Methods/Flight_Dynamics/Dynamic_Stability/Full_Linearized_Equations/Supporting_Functions/cm_q.py index 343f1f8250..dc942087c4 100644 --- a/trunk/SUAVE/Methods/Flight_Dynamics/Dynamic_Stability/Full_Linearized_Equations/Supporting_Functions/cm_q.py +++ b/trunk/SUAVE/Methods/Flight_Dynamics/Dynamic_Stability/Full_Linearized_Equations/Supporting_Functions/cm_q.py @@ -3,13 +3,14 @@ # # Created: Jun 2014, A. Wendorff # Modified: Jan 2016, E. Botero +# Modified: Nov 2022, D. Enriquez # ---------------------------------------------------------------------- # Method # ---------------------------------------------------------------------- ## @ingroup Methods-Flight_Dynamics-Dynamic_Stability-Full_Linearized_Equations-Supporting_Functions -def cm_q(cm_i, l_t, mac): +def cm_q(cla, vht, l_t, mac): """ This calculates the damping in pitch coefficient Assumptions: @@ -30,6 +31,6 @@ def cm_q(cm_i, l_t, mac): Properties Used: N/A """ - cm_q = 2. * 1.1 * cm_i * l_t / mac - - return cm_q \ No newline at end of file + cm_q = -2. * l_t / mac * vht * cla + cm_q = cm_q * 1.1 # factor to account for fuselage contribution + return cm_q