diff --git a/constraint_analysis/constraint_analysis_conf.xml b/constraint_analysis/constraint_analysis_conf.xml
index b48efabd5ebe4db380f9f68c932d6843fc37b234..5d9132019a9ab853c4ce25e24523cd936b5e8ee8 100644
--- a/constraint_analysis/constraint_analysis_conf.xml
+++ b/constraint_analysis/constraint_analysis_conf.xml
@@ -5,7 +5,7 @@
<value>CSMR-2020.xml</value>
</aircraft_exchange_file_name>
<aircraft_exchange_file_directory description="Specify the direction in which the aircraft exchange file can be found">
- <value>../projects/CSMR/CSMR-2020/</value>
+ <value>../projects2/</value>
</aircraft_exchange_file_directory>
<own_tool_level description="Specify the tool level of this tool">
<value>3</value>
@@ -109,11 +109,6 @@
<value>0.508</value>
</minimum_climb_rate>
</SEP>
- <approach_speed>
- <active>
- <value>true</value>
- </active>
- </approach_speed>
<landing_field_length>
<active>
<value>true</value>
@@ -121,6 +116,18 @@
<Mach>
<value>0.2</value>
</Mach>
+ <k_TD>
+ <value>1.15</value>
+ </k_TD>
+ <t_FR>
+ <value>3</value>
+ </t_FR>
+ <obstacle_height>
+ <value>15.4</value>
+ </obstacle_height>
+ <Mach>
+ <value>0.2</value>
+ </Mach>
</landing_field_length>
<gust>
<active>
diff --git a/constraint_analysis/include/constraint_analysis/ca_functions.h b/constraint_analysis/include/constraint_analysis/ca_functions.h
index a5126853267573559827cde2aba457a1a8cc6546..0dab17484a5be1305c06fe2b46e586e89638972e 100644
--- a/constraint_analysis/include/constraint_analysis/ca_functions.h
+++ b/constraint_analysis/include/constraint_analysis/ca_functions.h
@@ -184,6 +184,10 @@ namespace Mattingly {
*/
auto min_speed(double CL_max, double altitude, double Mach, double weight_fraction) -> const double;
+ auto approach_speed(double V_app, double CL_max, double weight_fraction, double s_A, double C_D, double h_obs, double k_TD, double altitude) -> const double;
+
+ auto get_V_stall(double V_app, double k_TD, double CL_max, double CD, double h_obs, double s_A) -> const double;
+
private:
// Membervariables
diff --git a/constraint_analysis/include/constraint_analysis/ca_minfinder.h b/constraint_analysis/include/constraint_analysis/ca_minfinder.h
index 674128172eb1cc626ca0a7966eb6781e2f542e82..ea0e3777bdda68e2756efc00640a13d3df5614ba 100644
--- a/constraint_analysis/include/constraint_analysis/ca_minfinder.h
+++ b/constraint_analysis/include/constraint_analysis/ca_minfinder.h
@@ -58,24 +58,27 @@ class Simple_Analysis : Analysis
{
public:
std::vector<double> dominant_thrust_to_weight = {};
- std::vector<double> wing_loading_boundaries = {};
+ double lower_wing_loading_boundary = {};
+ double upper_wing_loading_boundary = {};
std::vector<double> wing_loading_vec = {};
double design_thrust_to_weight = 1000.0;
double design_wing_loading = 0.0;
- Simple_Analysis(std::vector<Constraint> constraint_list, std::vector<double> boundaries) : Analysis(constraint_list)
+ Simple_Analysis(std::vector<Constraint> constraint_list, std::vector<double> lower_boundaries, std::vector<double> upper_boundaries) : Analysis(constraint_list)
{
dominant_thrust_to_weight = constraint_list[0].thrust_to_weight;
wing_loading_vec = constraint_list[0].wing_loading;
- wing_loading_boundaries = boundaries;
+ lower_wing_loading_boundary = *std::max_element(lower_boundaries.begin(), lower_boundaries.end());
+ upper_wing_loading_boundary = *std::min_element(upper_boundaries.begin(), upper_boundaries.end());
};
- Simple_Analysis(std::vector<Constraint> constraint_list, std::shared_ptr<node> acXML, std::vector<double> boundaries) :
+ Simple_Analysis(std::vector<Constraint> constraint_list, std::shared_ptr<node> acXML, std::vector<double> lower_boundaries, std::vector<double> upper_boundaries) :
Analysis(constraint_list, acXML)
{
dominant_thrust_to_weight = constraint_list[0].thrust_to_weight;
wing_loading_vec = constraint_list[0].wing_loading;
- wing_loading_boundaries = boundaries;
+ lower_wing_loading_boundary = *std::max_element(lower_boundaries.begin(), lower_boundaries.end());
+ upper_wing_loading_boundary = *std::min_element(upper_boundaries.begin(), upper_boundaries.end());
};
void find_dominant_curve() {
@@ -90,7 +93,7 @@ public:
void find_design_point(const double& safety_factor)
{
- std::sort(wing_loading_boundaries.begin(), wing_loading_boundaries.end());
+ std::vector<double> wing_loading_boundaries = { lower_wing_loading_boundary, upper_wing_loading_boundary };
std::vector<double> xlims = {};
for (auto x_limit : wing_loading_boundaries) {
auto it = std::distance(wing_loading_vec.begin(), std::lower_bound(wing_loading_vec.begin(), wing_loading_vec.end(), x_limit));
@@ -112,29 +115,38 @@ public:
void find_converged_design_point(const double& previous_TW, const double& previous_WS, const double& safety_factor, const double& buffer_factor)
{
- std::sort(wing_loading_boundaries.begin(), wing_loading_boundaries.end());
- std::vector<double> xlims = {};
- for (auto x_limit : wing_loading_boundaries) {
- auto it = std::distance(wing_loading_vec.begin(), std::lower_bound(wing_loading_vec.begin(), wing_loading_vec.end(), x_limit));
- xlims.push_back(it);
+ std::vector<double> wing_loading_boundaries = { lower_wing_loading_boundary, upper_wing_loading_boundary };
+ if (upper_wing_loading_boundary < lower_wing_loading_boundary)
+ {
+ design_thrust_to_weight = previous_TW;
+ design_wing_loading = previous_WS;
+ std::cout << "infeasable design space, loadings are not adjusted" << std::endl;
}
- std::vector<double> limited_TW(dominant_thrust_to_weight.begin() + xlims[0], dominant_thrust_to_weight.begin() + xlims[1]);
- int i = xlims[0];
- for (double point : limited_TW)
+ else
{
- if (point <= design_thrust_to_weight)
+ std::vector<double> xlims = {};
+ for (auto x_limit : wing_loading_boundaries) {
+ auto it = std::distance(wing_loading_vec.begin(), std::lower_bound(wing_loading_vec.begin(), wing_loading_vec.end(), x_limit));
+ xlims.push_back(it);
+ }
+ std::vector<double> limited_TW(dominant_thrust_to_weight.begin() + xlims[0], dominant_thrust_to_weight.begin() + xlims[1]);
+ int i = xlims[0];
+ for (double point : limited_TW)
{
- design_thrust_to_weight = point;
- design_wing_loading = wing_loading_vec[i];
+ if (point <= design_thrust_to_weight)
+ {
+ design_thrust_to_weight = point;
+ design_wing_loading = wing_loading_vec[i];
+ }
+ i++;
}
- i++;
- }
- design_thrust_to_weight = design_thrust_to_weight * (1.0 + safety_factor);
+ design_thrust_to_weight = design_thrust_to_weight * (1.0 + safety_factor);
- double relative_change_TW = sqrt(pow(1 - previous_TW / design_thrust_to_weight, 2));
- if (relative_change_TW <= buffer_factor/100.0) { design_thrust_to_weight = previous_TW; };
- double relative_change_WS = sqrt(pow(1 - previous_WS / design_wing_loading, 2));
- if (relative_change_WS <= buffer_factor/100.0) { design_wing_loading = previous_WS; };
+ double relative_change_TW = sqrt(pow(1 - previous_TW / design_thrust_to_weight, 2));
+ if (relative_change_TW <= buffer_factor / 100.0) { design_thrust_to_weight = previous_TW; };
+ double relative_change_WS = sqrt(pow(1 - previous_WS / design_wing_loading, 2));
+ if (relative_change_WS <= buffer_factor / 100.0) { design_wing_loading = previous_WS; };
+ };
};
template<typename T>
diff --git a/constraint_analysis/src/ca_functions.cpp b/constraint_analysis/src/ca_functions.cpp
index 738e818699064df2babaad2c3e338e13521da11c..f176ebd08e7f0be469640669c258325364a26f16 100644
--- a/constraint_analysis/src/ca_functions.cpp
+++ b/constraint_analysis/src/ca_functions.cpp
@@ -195,5 +195,37 @@ namespace Mattingly {
return W_over_S;
}
+ auto constraint_analysis::approach_speed(double V_app, double CL_max, double weight_fraction, double s_A, double C_D, double h_obs, double k_TD, double altitude) -> const double
+ {
+ double V_stall = 0.0;
+
+ // this is a 4th order polynomial with coefficients (a*x^4 + b*x^3 + c*x^2 + d*x + e = 0)
+ double a = -k_TD * CL_max;
+ double b = 0.;
+ double c = pow(V_app, 2.) * CL_max + 2. * h_obs * CL_max - s_A * k_TD;
+ double d = 0.;
+ double e = -s_A * V_app * C_D;
+
+ double del = pow(c, 2.) - 4. * a * e;
+
+ V_stall = std::max(std::sqrt((-c + sqrt(del)) / (2. * a)), std::sqrt((-c - sqrt(del)) / (2. * a)));
+
+ return pow(V_stall,2.)/(2.*weight_fraction/(atm.getDensity(altitude)*CL_max));
+ }
+
+ auto constraint_analysis::get_V_stall(double V_app, double k_TD, double CL_max, double CD, double h_obs, double s_A) -> const double
+ {
+ // this is a 4th order polynomial with coefficients (a*x^4 + b*x^3 + c*x^2 + d*x + e = 0)
+ double a = -k_TD * CL_max;
+ double b = 0.;
+ double c = pow(V_app, 2.) * CL_max + 2. * h_obs * CL_max - s_A * k_TD;
+ double d = 0.;
+ double e = -s_A * V_app * CD;
+
+ double del = pow(c, 2.) - 4. * a * e;
+
+ return std::max(std::sqrt((-c + sqrt(del)) / (2. * a)), std::sqrt((-c - sqrt(del)) / (2. * a)));
+ }
+
}
diff --git a/constraint_analysis/src/energy_based/energy_based.cpp b/constraint_analysis/src/energy_based/energy_based.cpp
index e11af9dfe6df0d64c8e8f945d950c7ff1b1c48f4..eb6c05e773465e0d6630cfe5e9d87b159e90a183 100644
--- a/constraint_analysis/src/energy_based/energy_based.cpp
+++ b/constraint_analysis/src/energy_based/energy_based.cpp
@@ -83,6 +83,9 @@ void EnergyBased::operator()()
W_over_S_data[i] = (WS_start + i) * 9.81;
}
+ this->lower_boundaries.push_back(50.0 * 9.81);
+ this->upper_boundaries.push_back(820.0 * 9.81);
+
Engine engine = Engine(this->engine_directory());
Mattingly::constraint_analysis constraint_analysis_tool;
@@ -113,7 +116,7 @@ void EnergyBased::operator()()
assess_constraints(W_over_S_data, constraint_analysis_tool, mission_data, engine);
/* Define Simple_Analysis*/
- Simple_Analysis min_finder = Simple_Analysis(this->constraint_list, this->aircraft_xml(), this->boundaries);
+ Simple_Analysis min_finder = Simple_Analysis(this->constraint_list, this->aircraft_xml(), this->lower_boundaries, this->upper_boundaries);
/* Find dominant curve of the design chart*/
min_finder.find_dominant_curve();
@@ -155,23 +158,26 @@ void EnergyBased::operator()()
}
this->constraint_list = {};
- this->boundaries = {};
+ this->lower_boundaries = { 50. * 9.81 };
+ this->upper_boundaries = { 820. * 9.81 };
assess_constraints(W_over_S_data, constraint_analysis_plotting, mission_data, engine);
- Simple_Analysis min_finder_2 = Simple_Analysis(this->constraint_list, this->aircraft_xml(), this->boundaries);
+ Simple_Analysis min_finder_2 = Simple_Analysis(this->constraint_list, this->aircraft_xml(), this->lower_boundaries, this->upper_boundaries);
min_finder_2.find_dominant_curve();
ConstraintAnalysis_Plot ca_plot;
+ std::vector<double> boundaries = { min_finder_2.lower_wing_loading_boundary , min_finder_2.upper_wing_loading_boundary };
+
ca_plot.fill_infeasible_area(W_over_S_data, min_finder_2.dominant_thrust_to_weight, boundaries);
for (auto ca_case : this->constraint_list)
{
ca_plot.add_curve(ca_case.wing_loading, ca_case.thrust_to_weight, ca_case.constraint_case);
}
- for (auto boundary : this->boundaries)
+ for (auto boundary : boundaries)
{
ca_plot.add_curve(boundary, "W/S limit");
}
@@ -328,27 +334,33 @@ void EnergyBased::assess_constraints(std::vector<double>& W_over_S_data, Mattin
minimum_climb_rate);
Constraint Case(W_over_S_data, constraint_vector, constraint->name);
this->constraint_list.push_back(Case);
- }
- else if (constraint->name == "approach_speed")
- {
-
}
else if (constraint->name == "landing_field_length")
{
- /* Landing */
+ double k_TD = constraint->at("k_TD/value");
+ double h_obs = constraint->at("obstacle_height/value");
double M = constraint->at("Mach/value");
- double thrust_lapse = calculate_thrust_lapse(M, 0.0);
+ double t_FR = constraint->at("t_FR/value");
+ double V_app = this->aircraft_xml()->at(
+ "aircraft_exchange_file/requirements_and_specifications/requirements/top_level_aircraft_requirements/flight_envelope/maximum_approach_speed/value");
double CL_max_L = this->aircraft_xml()->at("aircraft_exchange_file/analysis/aerodynamics/lift_coefficients/C_LmaxLanding/value");
- double my_B = this->aircraft_xml()->at("aircraft_exchange_file/requirements_and_specifications/requirements/additional_requirements/landing_gear/braking_coefficient/value");
- double s_G_L = 0.6 * this->aircraft_xml()->at("aircraft_exchange_file/requirements_and_specifications/requirements/top_level_aircraft_requirements/landing_field_length/value");
- // s_G_L as braking distance = 60% of landing field length
+ double s_A = h_obs / std::tan(3. * std::numbers::pi / 180.);
readPolar landing_config(this->polar(), "landing", "linear", M);
double CD_max_L = landing_config.interpCD(CL_max_L);
double max_landing_weight = this->aircraft_xml()->at("aircraft_exchange_file/analysis/masses_cg_inertia/maximum_landing_mass/mass_properties/mass/value");
double MTOM = this->aircraft_xml()->at("aircraft_exchange_file/analysis/masses_cg_inertia/maximum_takeoff_mass/mass_properties/mass/value");
double weight_fraction = max_landing_weight / MTOM;
+ const auto approach = constraint_analysis_tool.approach_speed(V_app, CL_max_L, weight_fraction, s_A, CD_max_L, h_obs, k_TD, 0.0);
+ this->upper_boundaries.push_back(approach);
+ double V_stall = constraint_analysis_tool.get_V_stall(V_app, k_TD, CL_max_L, CD_max_L, h_obs, s_A);
+ double s_FR = V_stall * k_TD * t_FR;
+
+ /* Landing */
+ double thrust_lapse = calculate_thrust_lapse(M, 0.0);
+ double my_B = this->aircraft_xml()->at("aircraft_exchange_file/requirements_and_specifications/requirements/additional_requirements/landing_gear/braking_coefficient/value");
+ double s_G_L = 0.6 * this->aircraft_xml()->at("aircraft_exchange_file/requirements_and_specifications/requirements/top_level_aircraft_requirements/landing_field_length/value") - s_A - s_FR;
const auto constraint_border = constraint_analysis_tool.braking_roll(CD_max_L, CL_max_L, weight_fraction, thrust_lapse, M, 0.0, my_B, s_G_L);
- this->boundaries.push_back(constraint_border);
+ this->upper_boundaries.push_back(constraint_border);
}
else if (constraint->name == "gust")
{
@@ -364,7 +376,7 @@ void EnergyBased::assess_constraints(std::vector<double>& W_over_S_data, Mattin
double w_g = this->configuration()->at("module_configuration_file/program_settings/constraint_selection/standard_set/gust/gust_speed/value");
double dn_G = this->configuration()->at("module_configuration_file/program_settings/constraint_selection/standard_set/gust/gust_load_factor/value");
const auto constraint_border = constraint_analysis_tool.gust(CL_alpha, 0.0, V_TO_L, w_g, dn_G, weight_fraction);
- this->boundaries.push_back(constraint_border);
+ this->lower_boundaries.push_back(constraint_border);
}
}
};
diff --git a/constraint_analysis/src/energy_based/energy_based.h b/constraint_analysis/src/energy_based/energy_based.h
index b8c56b24a7868ef269aab12a8475172acf2af084..3e48c381278b41cef14732ef9790ed89bd484d88 100644
--- a/constraint_analysis/src/energy_based/energy_based.h
+++ b/constraint_analysis/src/energy_based/energy_based.h
@@ -70,7 +70,8 @@ public:
void assess_constraints(std::vector<double>& W_over_S_data, Mattingly::constraint_analysis& constraint_analysis_tool, readMission& mission_data, Engine& engine);
std::vector<Constraint> constraint_list = {};
- std::vector<double> boundaries = {};
+ std::vector<double> lower_boundaries = {};
+ std::vector<double> upper_boundaries = {};
}; // namespace design
#endif // SRC_CONSTRAINT_ANALYSIS_ENERGY_BASED_H_
\ No newline at end of file