// Module: 10520c.c // Author: Phil Schubert // Date started: 12/03/99 // Purpose: Models a Continental IO-520-M Engine // Called by: FGSimExec // // Copyright (C) 1999 Philip L. Schubert (philings@ozemail.com.au) // // This program is free software; you can redistribute it and/or // modify it under the terms of the GNU General Public License as // published by the Free Software Foundation; either version 2 of the // License, or (at your option) any later version. // // This program is distributed in the hope that it will be useful, but // WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU // General Public License for more details. // // You should have received a copy of the GNU General Public License // along with this program; if not, write to the Free Software // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA // 02111-1307, USA. // // Further information about the GNU General Public License can also // be found on the world wide web at http://www.gnu.org. // // FUNCTIONAL DESCRIPTION // ------------------------------------------------------------------------ // Models a Continental IO-520-M engine. This engine is used in Cessna // 210, 310, Beechcraft Bonaza and Baron C55. The equations used below // were determined by a first and second order curve fits using Excel. // The data is from the Cessna Aircraft Corporations Engine and Flight // Computer for C310. Part Number D3500-13 // // ARGUMENTS // ------------------------------------------------------------------------ // // // HISTORY // ------------------------------------------------------------------------ // 12/03/99 PLS Created // 07/03/99 PLS Added Calculation of Density, and Prop_Torque // 07/03/99 PLS Restructered Variables to allow easier implementation // of Classes // 15/03/99 PLS Added Oil Pressure, Oil Temperature and CH Temp // ------------------------------------------------------------------------ // INCLUDES // ------------------------------------------------------------------------ #ifndef _IO360_HXX_ #define _IO360_HXX_ #include #include #include #include SG_USING_STD(ofstream); class FGNewEngine { private: float CONVERT_HP_TO_WATTS; float CONVERT_CUBIC_INCHES_TO_METERS_CUBED; // Control and environment inputs float IAS; // 0 = Closed, 100 = Fully Open float Throttle_Lever_Pos; // 0 = Full Course 100 = Full Fine float Propeller_Lever_Pos; // 0 = Idle Cut Off 100 = Full Rich float Mixture_Lever_Pos; // Engine Specific Variables used by this program that have limits. // Will be set in a parameter file to be read in to create // and instance for each engine. float Max_Manifold_Pressure; //will be lower than ambient pressure for a non turbo/super charged engine due to losses through the throttle. This is the sea level full throttle value. float Min_Manifold_Pressure; //Closed throttle valueat idle - governed by the idle bypass valve float Max_RPM; float Min_RPM; float Max_Fuel_Flow; float Mag_Derate_Percent; float MaxHP; float Gear_Ratio; // Initialise Engine Variables used by this instance float Percentage_Power; // Power output as percentage of maximum power output float Manifold_Pressure; // Inches float RPM; float Fuel_Flow_gals_hr; // gals/hour float Torque; float CHT; // Cylinder head temperature deg K float CHT_degF; // Ditto in deg Fahrenheit float EGT; // Exhaust gas temperature deg K float EGT_degF; // Exhaust gas temperature deg Fahrenheit float Mixture; float Oil_Pressure; // PSI float Oil_Temp; // Deg C float HP; // Current power output in HP float Power_SI; // Current power output in Watts float Torque_SI; // Torque in Nm float RPS; float Torque_Imbalance; bool started; //flag to indicate the engine is running self sustaining bool cranking; //flag to indicate the engine is being cranked //DCL float volumetric_efficiency; float combustion_efficiency; float equivalence_ratio; float v_dot_air; float m_dot_air; float m_dot_fuel; float swept_volume; float True_Manifold_Pressure; //in Hg float rho_air_manifold; float R_air; float p_amb_sea_level; // Pascals float p_amb; // Pascals float T_amb; // deg Kelvin float calorific_value_fuel; float rho_air; float rho_fuel; // kg/m^3 float thi_sea_level; float delta_T_exhaust; float displacement; // Engine displacement in cubic inches - to be read in from config file for each engine float displacement_SI; // ditto in meters cubed float Cp_air; // J/KgK float Cp_fuel; // J/KgK float heat_capacity_exhaust; float enthalpy_exhaust; float Percentage_of_best_power_mixture_power; float abstract_mixture; //temporary hack float engine_inertia; //kg.m^2 float prop_inertia; //kg.m^2 float angular_acceleration; //rad/s^2 double time_step; // Propellor Variables float FGProp1_Thrust; float FGProp1_RPS; float FGProp1_Blade_Angle; float prop_torque; // Nm float prop_thrust; // Newtons float blade_length; // meters float forward_velocity; // m/s float angular_velocity_SI; // rad/s float prop_power_consumed_SI; // Watts float prop_power_consumed_HP; // HP double prop_diameter; // meters double J; // advance ratio - dimensionless double Cp_20; // coefficient of power for 20 degree blade angle double Cp_25; // coefficient of power for 25 degree blade angle double Cp; // Our actual coefficient of power double blade_angle; // degrees double neta_prop_20; double neta_prop_25; double neta_prop; // prop efficiency // Calculate Engine RPM based on Propellor Lever Position float Calc_Engine_RPM(float Position); // Calculate Manifold Pressure based on throttle lever position // Note that this is simplistic and needs altering to include engine speed effects float Calc_Manifold_Pressure( float LeverPosn, float MaxMan, float MinMan); // Calculate combustion efficiency based on equivalence ratio float Lookup_Combustion_Efficiency(float thi_actual); // Calculate percentage of best power mixture power based on equivalence ratio float Power_Mixture_Correlation(float thi_actual); // Calculate exhaust gas temperature rise float Calculate_Delta_T_Exhaust(void); // Calculate Oil Temperature float Calc_Oil_Temp (float Fuel_Flow, float Mixture, float IAS); // Calculate Oil Pressure float Calc_Oil_Press (float Oil_Temp, float Engine_RPM); public: ofstream outfile; //constructor FGNewEngine() { // outfile.open("FGNewEngine.dat", ios::out|ios::trunc); } //destructor ~FGNewEngine() { // outfile.close(); } // set initial default values void init(double dt); // update the engine model based on current control positions void update(); inline void set_IAS( float value ) { IAS = value; } inline void set_Throttle_Lever_Pos( float value ) { Throttle_Lever_Pos = value; } inline void set_Propeller_Lever_Pos( float value ) { Propeller_Lever_Pos = value; } inline void set_Mixture_Lever_Pos( float value ) { Mixture_Lever_Pos = value; } // set ambient pressure - takes pounds per square foot inline void set_p_amb( float value ) { p_amb = value * 47.88026; // Convert to Pascals } // set ambient temperature - takes degrees Rankine inline void set_T_amb( float value ) { T_amb = value * 0.555555555556; // Convert to degrees Kelvin } // accessors inline float get_RPM() const { return RPM; } inline float get_Manifold_Pressure() const { return True_Manifold_Pressure; } inline float get_FGProp1_Thrust() const { return FGProp1_Thrust; } inline float get_FGProp1_Blade_Angle() const { return FGProp1_Blade_Angle; } // inline float get_Rho() const { return Rho; } inline float get_MaxHP() const { return MaxHP; } inline float get_Percentage_Power() const { return Percentage_Power; } inline float get_EGT() const { return EGT_degF; } // Returns EGT in Fahrenheit inline float get_CHT() const { return CHT_degF; } // Note this returns CHT in Fahrenheit inline float get_prop_thrust_SI() const { return prop_thrust; } inline float get_prop_thrust_lbs() const { return (prop_thrust * 0.2248); } inline float get_fuel_flow_gals_hr() const { return (Fuel_Flow_gals_hr); } }; #endif // _IO360_HXX_