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1 : : /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2 : :
3 : : Header: FGPropeller.h
4 : : Author: Jon S. Berndt
5 : : Date started: 08/24/00
6 : :
7 : : ------------- Copyright (C) 2000 Jon S. Berndt (jon@jsbsim.org) -------------
8 : :
9 : : This program is free software; you can redistribute it and/or modify it under
10 : : the terms of the GNU Lesser General Public License as published by the Free Software
11 : : Foundation; either version 2 of the License, or (at your option) any later
12 : : version.
13 : :
14 : : This program is distributed in the hope that it will be useful, but WITHOUT
15 : : ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
16 : : FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
17 : : details.
18 : :
19 : : You should have received a copy of the GNU Lesser General Public License along with
20 : : this program; if not, write to the Free Software Foundation, Inc., 59 Temple
21 : : Place - Suite 330, Boston, MA 02111-1307, USA.
22 : :
23 : : Further information about the GNU Lesser General Public License can also be found on
24 : : the world wide web at http://www.gnu.org.
25 : :
26 : : HISTORY
27 : : --------------------------------------------------------------------------------
28 : : 08/24/00 JSB Created
29 : :
30 : : %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
31 : : SENTRY
32 : : %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
33 : :
34 : : #ifndef FGPROPELLER_H
35 : : #define FGPROPELLER_H
36 : :
37 : : /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
38 : : INCLUDES
39 : : %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
40 : :
41 : : #include "FGThruster.h"
42 : : #include "math/FGTable.h"
43 : :
44 : : /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
45 : : DEFINITIONS
46 : : %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
47 : :
48 : : #define ID_PROPELLER "$Id: FGPropeller.h,v 1.16 2010/04/09 12:44:06 jberndt Exp $"
49 : :
50 : : /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
51 : : FORWARD DECLARATIONS
52 : : %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
53 : :
54 : : namespace JSBSim {
55 : :
56 : : /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
57 : : CLASS DOCUMENTATION
58 : : %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
59 : :
60 : : /** FGPropeller models a propeller given the tabular data for Ct and Cp,
61 : : indexed by the advance ratio "J".
62 : :
63 : : <h3>Configuration File Format:</h3>
64 : : @code
65 : : <propeller name="{string}">
66 : : <ixx> {number} </ixx>
67 : : <diameter unit="IN"> {number} </diameter>
68 : : <numblades> {number} </numblades>
69 : : <gearratio> {number} </gearratio>
70 : : <minpitch> {number} </minpitch>
71 : : <maxpitch> {number} </maxpitch>
72 : : <minrpm> {number} </minrpm>
73 : : <maxrpm> {number} </maxrpm>
74 : : <constspeed> {number} </constspeed>
75 : : <reversepitch> {number} </reversepitch>
76 : : <sense> {1 | -1} </sense>
77 : : <p_factor> {number} </p_factor>
78 : : <ct_factor> {number} </ct_factor>
79 : : <cp_factor> {number} </cp_factor>
80 : :
81 : : <table name="C_THRUST" type="internal">
82 : : <tableData>
83 : : {numbers}
84 : : </tableData>
85 : : </table>
86 : :
87 : : <table name="C_POWER" type="internal">
88 : : <tableData>
89 : : {numbers}
90 : : </tableData>
91 : : </table>
92 : :
93 : : <table name="CT_MACH" type="internal">
94 : : <tableData>
95 : : {numbers}
96 : : </tableData>
97 : : </table>
98 : :
99 : : <table name="CP_MACH" type="internal">
100 : : <tableData>
101 : : {numbers}
102 : : </tableData>
103 : : </table>
104 : :
105 : :
106 : : </propeller>
107 : : @endcode
108 : :
109 : : <h3>Configuration Parameters:</h3>
110 : : <pre>
111 : : \<ixx> - Propeller rotational inertia.
112 : : \<diameter> - Propeller disk diameter.
113 : : \<numblades> - Number of blades.
114 : : \<gearratio> - Ratio of (engine rpm) / (prop rpm).
115 : : \<minpitch> - Minimum blade pitch angle.
116 : : \<maxpitch> - Maximum blade pitch angle.
117 : : \<minrpm> - Minimum rpm target for constant speed propeller.
118 : : \<maxrpm> - Maximum rpm target for constant speed propeller.
119 : : \<constspeed> - 1 = constant speed mode, 0 = manual pitch mode.
120 : : \<reversepitch> - Blade pitch angle for reverse.
121 : : \<sense> - Direction of rotation (1=clockwise as viewed from cockpit,
122 : : -1=anti-clockwise as viewed from cockpit).
123 : : \<p_factor> - P factor.
124 : : \<ct_factor> - A multiplier for the coefficients of thrust.
125 : : \<cp_factor> - A multiplier for the coefficients of power.
126 : : </pre>
127 : :
128 : : Two tables are needed. One for coefficient of thrust (Ct) and one for
129 : : coefficient of power (Cp).
130 : :
131 : : Two tables are optional. They apply a factor to Ct and Cp based on the
132 : : helical tip Mach.
133 : : <br>
134 : :
135 : : Several references were helpful, here:<ul>
136 : : <li>Barnes W. McCormick, "Aerodynamics, Aeronautics, and Flight Mechanics",
137 : : Wiley & Sons, 1979 ISBN 0-471-03032-5</li>
138 : : <li>Edwin Hartman, David Biermann, "The Aerodynamic Characteristics of
139 : : Full Scale Propellers Having 2, 3, and 4 Blades of Clark Y and R.A.F. 6
140 : : Airfoil Sections", NACA Report TN-640, 1938 (?)</li>
141 : : <li>Various NACA Technical Notes and Reports</li>
142 : : </ul>
143 : : @author Jon S. Berndt
144 : : @version $Id: FGPropeller.h,v 1.16 2010/04/09 12:44:06 jberndt Exp $
145 : : @see FGEngine
146 : : @see FGThruster
147 : : */
148 : :
149 : : /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
150 : : CLASS DECLARATION
151 : : %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
152 : :
153 : : class FGPropeller : public FGThruster {
154 : :
155 : : public:
156 : : /** Constructor for FGPropeller.
157 : : @param exec a pointer to the main executive object
158 : : @param el a pointer to the thruster config file XML element
159 : : @param num the number of this propeller */
160 : : FGPropeller(FGFDMExec* exec, Element* el, int num = 0);
161 : :
162 : : /// Destructor for FGPropeller - deletes the FGTable objects
163 : : ~FGPropeller();
164 : :
165 : : /** Sets the Revolutions Per Minute for the propeller. Normally the propeller
166 : : instance will calculate its own rotational velocity, given the Torque
167 : : produced by the engine and integrating over time using the standard
168 : : equation for rotational acceleration "a": a = Q/I , where Q is Torque and
169 : : I is moment of inertia for the propeller.
170 : : @param rpm the rotational velocity of the propeller */
171 : 0 : void SetRPM(double rpm) {RPM = rpm;}
172 : :
173 : : /// Returns true of this propeller is variable pitch
174 : 0 : bool IsVPitch(void) {return MaxPitch != MinPitch;}
175 : :
176 : : /** This commands the pitch of the blade to change to the value supplied.
177 : : This call is meant to be issued either from the cockpit or by the flight
178 : : control system (perhaps to maintain constant RPM for a constant-speed
179 : : propeller). This value will be limited to be within whatever is specified
180 : : in the config file for Max and Min pitch. It is also one of the lookup
181 : : indices to the power and thrust tables for variable-pitch propellers.
182 : : @param pitch the pitch of the blade in degrees. */
183 : : void SetPitch(double pitch) {Pitch = pitch;}
184 : :
185 : 0 : void SetAdvance(double advance) {Advance = advance;}
186 : :
187 : : /// Sets the P-Factor constant
188 : : void SetPFactor(double pf) {P_Factor = pf;}
189 : :
190 : : /// Sets propeller into constant speed mode, or manual pitch mode
191 : 0 : void SetConstantSpeed(int mode) {ConstantSpeed = mode;}
192 : :
193 : : /// Sets coefficient of thrust multiplier
194 : 0 : void SetCtFactor(double ctf) {CtFactor = ctf;}
195 : :
196 : : /// Sets coefficient of power multiplier
197 : 0 : void SetCpFactor(double cpf) {CpFactor = cpf;}
198 : :
199 : : /** Sets the rotation sense of the propeller.
200 : : @param s this value should be +/- 1 ONLY. +1 indicates clockwise rotation as
201 : : viewed by someone standing behind the engine looking forward into
202 : : the direction of flight. */
203 : 0 : void SetSense(double s) { Sense = s;}
204 : :
205 : : /// Retrieves the pitch of the propeller in degrees.
206 : : double GetPitch(void) { return Pitch; }
207 : :
208 : : /// Retrieves the RPMs of the propeller
209 : 0 : double GetRPM(void) const { return RPM; }
210 : :
211 : : /// Retrieves the propeller moment of inertia
212 : : double GetIxx(void) { return Ixx; }
213 : :
214 : : /// Retrieves the coefficient of thrust multiplier
215 : : double GetCtFactor(void) { return CtFactor; }
216 : :
217 : : /// Retrieves the coefficient of power multiplier
218 : : double GetCpFactor(void) { return CpFactor; }
219 : :
220 : : /// Retrieves the propeller diameter
221 : : double GetDiameter(void) { return Diameter; }
222 : :
223 : : /// Retrieves propeller thrust table
224 : : FGTable* GetCThrustTable(void) const { return cThrust;}
225 : : /// Retrieves propeller power table
226 : : FGTable* GetCPowerTable(void) const { return cPower; }
227 : :
228 : : /// Retrieves propeller thrust Mach effects factor
229 : : FGTable* GetCtMachTable(void) const { return CtMach; }
230 : : /// Retrieves propeller power Mach effects factor
231 : : FGTable* GetCpMachTable(void) const { return CpMach; }
232 : :
233 : : /// Retrieves the Torque in foot-pounds (Don't you love the English system?)
234 : 0 : double GetTorque(void) { return vTorque(eX); }
235 : :
236 : : /** Retrieves the power required (or "absorbed") by the propeller -
237 : : i.e. the power required to keep spinning the propeller at the current
238 : : velocity, air density, and rotational rate. */
239 : : double GetPowerRequired(void);
240 : :
241 : : /** Calculates and returns the thrust produced by this propeller.
242 : : Given the excess power available from the engine (in foot-pounds), the thrust is
243 : : calculated, as well as the current RPM. The RPM is calculated by integrating
244 : : the torque provided by the engine over what the propeller "absorbs"
245 : : (essentially the "drag" of the propeller).
246 : : @param PowerAvailable this is the excess power provided by the engine to
247 : : accelerate the prop. It could be negative, dictating that the propeller
248 : : would be slowed.
249 : : @return the thrust in pounds */
250 : : double Calculate(double PowerAvailable);
251 : : FGColumnVector3 GetPFactor(void);
252 : : string GetThrusterLabels(int id, string delimeter);
253 : : string GetThrusterValues(int id, string delimeter);
254 : :
255 : 0 : void SetReverseCoef (double c) { Reverse_coef = c; }
256 : : double GetReverseCoef (void) { return Reverse_coef; }
257 : 0 : void SetReverse (bool r) { Reversed = r; }
258 : : bool GetReverse (void) { return Reversed; }
259 : 0 : void SetFeather (bool f) { Feathered = f; }
260 : : bool GetFeather (void) { return Feathered; }
261 : 0 : double GetThrustCoefficient(void) const {return ThrustCoeff;}
262 : 0 : double GetHelicalTipMach(void) const {return HelicalTipMach;}
263 : 0 : int GetConstantSpeed(void) const {return ConstantSpeed;}
264 : 0 : void SetInducedVelocity(double Vi) {Vinduced = Vi;}
265 : 0 : double GetInducedVelocity(void) const {return Vinduced;}
266 : :
267 : : private:
268 : : int numBlades;
269 : : double J;
270 : : double RPM;
271 : : double Ixx;
272 : : double Diameter;
273 : : double MaxPitch;
274 : : double MinPitch;
275 : : double MinRPM;
276 : : double MaxRPM;
277 : : double Pitch;
278 : : double P_Factor;
279 : : double Sense;
280 : : double Advance;
281 : : double ExcessTorque;
282 : : double D4;
283 : : double D5;
284 : : double HelicalTipMach;
285 : : double Vinduced;
286 : : FGColumnVector3 vTorque;
287 : : FGTable *cThrust;
288 : : FGTable *cPower;
289 : : FGTable *CtMach;
290 : : FGTable *CpMach;
291 : : double CtFactor;
292 : : double CpFactor;
293 : : int ConstantSpeed;
294 : : void Debug(int from);
295 : : double ReversePitch; // Pitch, when fully reversed
296 : : bool Reversed; // true, when propeller is reversed
297 : : double Reverse_coef; // 0 - 1 defines AdvancePitch (0=MIN_PITCH 1=REVERSE_PITCH)
298 : : bool Feathered; // true, if feather command
299 : : };
300 : : }
301 : : //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
302 : : #endif
303 : :
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