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