/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Header: FGPropeller.h Author: Jon S. Berndt Date started: 08/24/00 ------------- Copyright (C) 2000 Jon S. Berndt (jon@jsbsim.org) ------------- This program is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser 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 Lesser General Public License for more details. You should have received a copy of the GNU Lesser 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 Lesser General Public License can also be found on the world wide web at http://www.gnu.org. HISTORY -------------------------------------------------------------------------------- 08/24/00 JSB Created %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% SENTRY %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/ #ifndef FGPROPELLER_H #define FGPROPELLER_H /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% INCLUDES %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/ #include "FGThruster.h" #include "math/FGTable.h" /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% DEFINITIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/ #define ID_PROPELLER "$Id: FGPropeller.h,v 1.21 2013/11/15 22:43:03 bcoconni Exp $" /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% FORWARD DECLARATIONS %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/ namespace JSBSim { /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% CLASS DOCUMENTATION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/ /** FGPropeller models a propeller given the tabular data for Ct and Cp, indexed by the advance ratio "J".

Configuration File Format:

@code {1 | -1} {number} {number} {number} {number} {number} {number} {number} {number} {number} {number} {number} {number} {number} {numbers}
{numbers}
{numbers}
{numbers}
@endcode

Configuration Parameters:

    \           - Propeller rotational inertia.
    \      - Propeller disk diameter.
    \     - Number of blades.
    \     - Ratio of (engine rpm) / (prop rpm).
    \      - Minimum blade pitch angle.
    \      - Maximum blade pitch angle.
    \        - Minimum rpm target for constant speed propeller.
    \        - Maximum rpm target for constant speed propeller.
    \    - 1 = constant speed mode, 0 = manual pitch mode. 
    \  - Blade pitch angle for reverse.
    \         - Direction of rotation (1=clockwise as viewed from cockpit,
                        -1=anti-clockwise as viewed from cockpit). Sense is
                       specified in the parent tag of the propeller.
    \      - P factor.
    \     - A multiplier for the coefficients of thrust.
    \     - A multiplier for the coefficients of power.
Two tables are needed. One for coefficient of thrust (Ct) and one for coefficient of power (Cp). Two tables are optional. They apply a factor to Ct and Cp based on the helical tip Mach.
Several references were helpful, here: @author Jon S. Berndt @version $Id: FGPropeller.h,v 1.21 2013/11/15 22:43:03 bcoconni Exp $ @see FGEngine @see FGThruster */ /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% CLASS DECLARATION %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/ class FGPropeller : public FGThruster { public: /** Constructor for FGPropeller. @param exec a pointer to the main executive object @param el a pointer to the thruster config file XML element @param num the number of this propeller */ FGPropeller(FGFDMExec* exec, Element* el, int num = 0); /// Destructor for FGPropeller - deletes the FGTable objects ~FGPropeller(); /** Sets the Revolutions Per Minute for the propeller. Normally the propeller instance will calculate its own rotational velocity, given the Torque produced by the engine and integrating over time using the standard equation for rotational acceleration "a": a = Q/I , where Q is Torque and I is moment of inertia for the propeller. @param rpm the rotational velocity of the propeller */ void SetRPM(double rpm) {RPM = rpm;} /** Sets the Revolutions Per Minute for the propeller using the engine gear ratio **/ void SetEngineRPM(double rpm) {RPM = rpm/GearRatio;} /// Returns true of this propeller is variable pitch bool IsVPitch(void) const {return MaxPitch != MinPitch;} /** This commands the pitch of the blade to change to the value supplied. This call is meant to be issued either from the cockpit or by the flight control system (perhaps to maintain constant RPM for a constant-speed propeller). This value will be limited to be within whatever is specified in the config file for Max and Min pitch. It is also one of the lookup indices to the power and thrust tables for variable-pitch propellers. @param pitch the pitch of the blade in degrees. */ void SetPitch(double pitch) {Pitch = pitch;} void SetAdvance(double advance) {Advance = advance;} /// Sets the P-Factor constant void SetPFactor(double pf) {P_Factor = pf;} /// Sets propeller into constant speed mode, or manual pitch mode void SetConstantSpeed(int mode) {ConstantSpeed = mode;} /// Sets coefficient of thrust multiplier void SetCtFactor(double ctf) {CtFactor = ctf;} /// Sets coefficient of power multiplier void SetCpFactor(double cpf) {CpFactor = cpf;} /** Sets the rotation sense of the propeller. @param s this value should be +/- 1 ONLY. +1 indicates clockwise rotation as viewed by someone standing behind the engine looking forward into the direction of flight. */ void SetSense(double s) { Sense = s;} /// Retrieves the pitch of the propeller in degrees. double GetPitch(void) const { return Pitch; } /// Retrieves the RPMs of the propeller double GetRPM(void) const { return RPM; } /// Calculates the RPMs of the engine based on gear ratio double GetEngineRPM(void) const { return RPM * GearRatio; } /// Retrieves the propeller moment of inertia double GetIxx(void) const { return Ixx; } /// Retrieves the coefficient of thrust multiplier double GetCtFactor(void) const { return CtFactor; } /// Retrieves the coefficient of power multiplier double GetCpFactor(void) const { return CpFactor; } /// Retrieves the propeller diameter double GetDiameter(void) const { return Diameter; } /// Retrieves propeller thrust table FGTable* GetCThrustTable(void) const { return cThrust;} /// Retrieves propeller power table FGTable* GetCPowerTable(void) const { return cPower; } /// Retrieves propeller thrust Mach effects factor FGTable* GetCtMachTable(void) const { return CtMach; } /// Retrieves propeller power Mach effects factor FGTable* GetCpMachTable(void) const { return CpMach; } /// Retrieves the Torque in foot-pounds (Don't you love the English system?) double GetTorque(void) const { return vTorque(eX); } /** Retrieves the power required (or "absorbed") by the propeller - i.e. the power required to keep spinning the propeller at the current velocity, air density, and rotational rate. */ double GetPowerRequired(void); /** Calculates and returns the thrust produced by this propeller. Given the excess power available from the engine (in foot-pounds), the thrust is calculated, as well as the current RPM. The RPM is calculated by integrating the torque provided by the engine over what the propeller "absorbs" (essentially the "drag" of the propeller). @param PowerAvailable this is the excess power provided by the engine to accelerate the prop. It could be negative, dictating that the propeller would be slowed. @return the thrust in pounds */ double Calculate(double EnginePower); FGColumnVector3 GetPFactor(void) const; std::string GetThrusterLabels(int id, const std::string& delimeter); std::string GetThrusterValues(int id, const std::string& delimeter); void SetReverseCoef (double c) { Reverse_coef = c; } double GetReverseCoef (void) const { return Reverse_coef; } void SetReverse (bool r) { Reversed = r; } bool GetReverse (void) const { return Reversed; } void SetFeather (bool f) { Feathered = f; } bool GetFeather (void) const { return Feathered; } double GetThrustCoefficient(void) const {return ThrustCoeff;} double GetHelicalTipMach(void) const {return HelicalTipMach;} int GetConstantSpeed(void) const {return ConstantSpeed;} void SetInducedVelocity(double Vi) {Vinduced = Vi;} double GetInducedVelocity(void) const {return Vinduced;} private: int numBlades; double J; double RPM; double Ixx; double Diameter; double MaxPitch; double MinPitch; double MinRPM; double MaxRPM; double Pitch; double P_Factor; double Sense; double Advance; double ExcessTorque; double D4; double D5; double HelicalTipMach; double Vinduced; FGColumnVector3 vTorque; FGTable *cThrust; FGTable *cPower; FGTable *CtMach; FGTable *CpMach; double CtFactor; double CpFactor; int ConstantSpeed; void Debug(int from); double ReversePitch; // Pitch, when fully reversed bool Reversed; // true, when propeller is reversed double Reverse_coef; // 0 - 1 defines AdvancePitch (0=MIN_PITCH 1=REVERSE_PITCH) bool Feathered; // true, if feather command }; } //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% #endif