Goodbye automake.

[flightgear.git] / src / FDM / UIUCModel / uiuc_iced_nonlin.cpp

diff --git a/src/FDM/UIUCModel/uiuc_iced_nonlin.cpp b/src/FDM/UIUCModel/uiuc_iced_nonlin.cpp
index 6a215d1a4568660801dd5c7aa60daf5aa8638bc2..30ac008fa5637fb57fc9a96fe5579e1548abf82d 100644 (file)
--- a/src/FDM/UIUCModel/uiuc_iced_nonlin.cpp
+++ b/src/FDM/UIUCModel/uiuc_iced_nonlin.cpp
@@ -2,6 +2,9 @@
 //     Version 020409
 //     read readme_020212.doc for information
 
+// 11-21-2002 (RD) Added e code from Kishwar to fix negative lift problem at
+//            high etas
+
 #include "uiuc_iced_nonlin.h"
 
 void Calc_Iced_Forces()
@@ -10,8 +13,9 @@ void Calc_Iced_Forces()
          double alpha;
          double de;
        double eta_ref_wing = 0.08;                      // eta of iced data used for curve fit
-       double eta_ref_tail = 0.12;
+       double eta_ref_tail = 0.20; //changed from 0.12 10-23-2002
        double eta_wing;
+       double e;
        //double delta_CL;                              // CL_clean - CL_iced;
        //double delta_CD;                              // CD_clean - CD_iced;
        //double delta_Cm;                              // CM_clean - CM_iced;
@@ -25,16 +29,17 @@ void Calc_Iced_Forces()
        double KCm_de;
        double KCh;
        double CL_diff;
+       double CD_diff;
        
        
        
-       alpha = Alpha*RAD_TO_DEG;
+       alpha = Std_Alpha*RAD_TO_DEG;
        de = elevator*RAD_TO_DEG;
        // lift fits
        if (alpha < 16)
                {
                delta_CL = (0.088449 + 0.004836*alpha - 0.0005459*alpha*alpha +
-                                       4.0859e-5*pow(alpha,3));
+                           4.0859e-5*pow(alpha,3));
                }
        else
                {
@@ -43,12 +48,20 @@ void Calc_Iced_Forces()
                }
        KCL = -delta_CL/eta_ref_wing;
        eta_wing = 0.5*(eta_wing_left + eta_wing_right);
-       delta_CL = eta_wing*KCL;
+       if (eta_wing <= 0.1)
+         {
+           e = eta_wing;
+         }
+       else
+         {
+           e = -0.3297*exp(-5*eta_wing)+0.3;
+         }
+       delta_CL = e*KCL;
        
                
        // drag fit
        delta_CD = (-0.0089 + 0.001578*alpha - 0.00046253*pow(alpha,2) +
-                                       -4.7511e-5*pow(alpha,3) + 2.3384e-6*pow(alpha,4));
+                   -4.7511e-5*pow(alpha,3) + 2.3384e-6*pow(alpha,4));
        KCD = -delta_CD/eta_ref_wing;
        delta_CD = eta_wing*KCD;
        
@@ -57,7 +70,7 @@ void Calc_Iced_Forces()
                      - 4.0692e-5*pow(alpha,3) + 1.7594e-6*pow(alpha,4));
                                        
        delta_Cm_de = (-0.014928 - 0.0037783*alpha + 0.00039086*pow(de,2)
-                                       - 1.1304e-5*pow(de,3) - 1.8439e-6*pow(de,4));
+                      - 1.1304e-5*pow(de,3) - 1.8439e-6*pow(de,4));
                                        
        delta_Cm = delta_Cm_a + delta_Cm_de;
        KCm_alpha = delta_Cm_a/eta_ref_wing;
@@ -66,14 +79,14 @@ void Calc_Iced_Forces()
        
        // hinge moment
        if (alpha < 13)
-               {
-               delta_Ch_a = (-0.0012862 - 0.00022705*alpha + 1.5911e-5*pow(alpha,2)
-                                               + 5.4536e-7*pow(alpha,3));
-               }
+         {
+           delta_Ch_a = (-0.0012862 - 0.00022705*alpha + 1.5911e-5*pow(alpha,2)
+                         + 5.4536e-7*pow(alpha,3));
+         }
        else
-               {
-               delta_Ch_a = 0;
-               }
+         {
+           delta_Ch_a = 0;
+         }
        delta_Ch_e = -0.0011851 - 0.00049924*de;
        delta_Ch = -(delta_Ch_a + delta_Ch_e);
        KCh = -delta_Ch/eta_ref_tail;
@@ -81,31 +94,42 @@ void Calc_Iced_Forces()
        
        // rolling moment
        CL_diff = (eta_wing_left - eta_wing_right)*KCL;
-       delta_Cl = CL_diff/4;
+       delta_Cl = CL_diff/8.; // 10-23-02 Previously 4
+
+       //yawing moment
+       CD_diff = (eta_wing_left - eta_wing_right)*KCD;
+       delta_Cn = CD_diff/8.;
        
        }
 
 void add_ice_effects()
 {
-  CL_clean = -1*CZ*cos(Alpha) + CX*sin(Alpha);  //Check later
-  CD_clean = -1*CZ*sin(Alpha) - CX*cos(Alpha);
+  CD_clean = -1*CX*Cos_alpha*Cos_beta - CY*Sin_beta - CZ*Sin_alpha*Cos_beta;
+  CY_clean = -1*CX*Cos_alpha*Sin_beta + CY*Cos_beta - CZ*Sin_alpha*Sin_beta;
+  CL_clean = CX*Sin_alpha - CZ*Cos_alpha;
   Cm_clean = Cm;
   Cl_clean = Cl;
+  Cn_clean = Cn;
   Ch_clean = Ch;
 
-  CL_iced = CL_clean + delta_CL;
   CD_iced = CD_clean + delta_CD;
+  CY_iced = CY_clean;
+  CL_iced = CL_clean + delta_CL;
   Cm_iced = Cm_clean + delta_Cm;
   Cl_iced = Cl_clean + delta_Cl;
+  Cn_iced = Cn_clean + delta_Cn;
   //Ch_iced = Ch_clean + delta_Ch;
 
-  CL = CL_iced;
   CD = CD_iced;
+  CY = CY_iced;
+  CL = CL_iced;
   Cm = Cm_iced;
   Cl = Cl_iced;
+  Cn = Cn_iced;
   //Ch = Ch_iced;
 
-  CZ = -1*CL*cos(Alpha) - CD*sin(Alpha);
-  CX = CL*sin(Alpha) - CD*cos(Alpha);
+  CX = -1*CD*Cos_alpha*Cos_beta - CY*Cos_alpha*Sin_beta + CL*Sin_alpha;
+  CY = -1*CD*Sin_beta + CY*Cos_beta;
+  CZ = -1*CD*Sin_alpha*Cos_beta - CY*Sin_alpha*Sin_beta - CL*Cos_alpha;
 
 }