168 lines
6.6 KiB
C++
168 lines
6.6 KiB
C++
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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Header: FGPropeller.h
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Author: Jon S. Berndt
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Date started: 08/24/00
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------------- Copyright (C) 2000 Jon S. Berndt (jsb@hal-pc.org) -------------
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This program is free software; you can redistribute it and/or modify it under
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the terms of the GNU General Public License as published by the Free Software
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Foundation; either version 2 of the License, or (at your option) any later
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version.
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This program is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
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FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
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details.
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You should have received a copy of the GNU General Public License along with
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this program; if not, write to the Free Software Foundation, Inc., 59 Temple
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Place - Suite 330, Boston, MA 02111-1307, USA.
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Further information about the GNU General Public License can also be found on
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the world wide web at http://www.gnu.org.
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HISTORY
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--------------------------------------------------------------------------------
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08/24/00 JSB Created
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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SENTRY
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
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#ifndef FGPROPELLER_H
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#define FGPROPELLER_H
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/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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INCLUDES
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
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#include "FGThruster.h"
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#include "FGTable.h"
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#include "FGTranslation.h"
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/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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DEFINITIONS
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
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#define ID_PROPELLER "$Id$"
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#ifndef M_PI
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# include <simgear/constants.h>
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# define M_PI SG_PI
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#endif
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/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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FORWARD DECLARATIONS
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
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/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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COMMENTS, REFERENCES, and NOTES [use "class documentation" below for API docs]
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
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/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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CLASS DOCUMENTATION
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
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/** Propeller modeling class.
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FGPropeller models a propeller given the tabular data for Ct, Cp, and
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efficiency indexed by advance ratio "J". The data for the propeller is
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stored in a config file named "prop_name.xml". The propeller config file
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is referenced from the main aircraft config file in the "Propulsion" section.
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See the constructor for FGPropeller to see what is read in and what should
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be stored in the config file.<br>
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Several references were helpful, here:<ul>
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<li>Barnes W. McCormick, "Aerodynamics, Aeronautics, and Flight Mechanics",
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Wiley & Sons, 1979 ISBN 0-471-03032-5</li>
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<li>Edwin Hartman, David Biermann, "The Aerodynamic Characteristics of
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Full Scale Propellers Having 2, 3, and 4 Blades of Clark Y and R.A.F. 6
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Airfoil Sections", NACA Report TN-640, 1938 (?)</li>
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<li>Various NACA Technical Notes and Reports</li>
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<ul>
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@author Jon S. Berndt
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@version $Id$
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@see FGEngine
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@see FGThruster
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@see FGTable
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*/
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/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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CLASS DECLARATION
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
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class FGPropeller : public FGThruster {
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public:
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/** Constructor for FGPropeller.
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@param exec a pointer to the main executive object
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@param AC_cfg a pointer to the main aircraft config file object */
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FGPropeller(FGFDMExec* exec, FGConfigFile* AC_cfg);
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/// Destructor for FGPropeller - deletes the FGTable objects
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~FGPropeller();
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/** Sets the Revolutions Per Minute for the propeller. Normally the propeller
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instance will calculate its own rotational velocity, given the Torque
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produced by the engine and integrating over time using the standard
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equation for rotational acceleration "a": a = Q/I , where Q is Torque and
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I is moment of inertia for the propeller.
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@param rpm the rotational velocity of the propeller */
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void SetRPM(float rpm) {RPM = rpm;}
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/** This commands the pitch of the blade to change to the value supplied.
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This call is meant to be issued either from the cockpit or by the flight
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control system (perhaps to maintain constant RPM for a constant-speed
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propeller). This value will be limited to be within whatever is specified
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in the config file for Max and Min pitch. It is also one of the lookup
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indices to the power, thrust, and efficiency tables for variable-pitch
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propellers.
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@param pitch the pitch of the blade in degrees. */
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void SetPitch(float pitch) {Pitch = pitch;}
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/// Retrieves the pitch of the propeller in degrees.
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float GetPitch(void) { return Pitch; }
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/// Retrieves the RPMs of the propeller
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float GetRPM(void) { return RPM; }
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/// Retrieves the propeller moment of inertia
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float GetIxx(void) { return Ixx; }
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/// Retrieves the Torque in foot-pounds (Don't you love the English system?)
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float GetTorque(void) { return Torque; }
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/** Retrieves the power required (or "absorbed") by the propeller -
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i.e. the power required to keep spinning the propeller at the current
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velocity, air density, and rotational rate. */
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float GetPowerRequired(void);
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/** Calculates and returns the thrust produced by this propeller.
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Given the excess power available from the engine (in foot-pounds), the thrust is
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calculated, as well as the current RPM. The RPM is calculated by integrating
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the torque provided by the engine over what the propeller "absorbs"
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(essentially the "drag" of the propeller).
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@param PowerAvailable this is the excess power provided by the engine to
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accelerate the prop. It could be negative, dictating that the propeller
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would be slowed.
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@return the thrust in pounds */
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float Calculate(float PowerAvailable);
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private:
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int numBlades;
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float RPM;
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float Ixx;
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float Diameter;
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float MaxPitch;
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float MinPitch;
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float Pitch;
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float Torque;
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FGTable *Efficiency;
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FGTable *cThrust;
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FGTable *cPower;
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void Debug(void);
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};
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//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
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#endif
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