Polar file formats - Revision history

Ola at 00:36, 6 March 2007

2007-03-06T00:36:58Z

← Older revision		Revision as of 00:36, 6 March 2007
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	set {		set {
	deflection = -20.0		deflection = -20.0
			# alpha cl cd cm
	p = [ -20.000 -1.2712 0.303250 0.2140 ]		p = [ -20.000 -1.2712 0.303250 0.2140 ]
	p = [ -15.000 -1.6465 0.097880 0.0669 ]		p = [ -15.000 -1.6465 0.097880 0.0669 ]

Ola at 23:40, 5 March 2007

2007-03-05T23:40:43Z

← Older revision		Revision as of 23:40, 5 March 2007
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			[[Category:Aircraft Physics]]

	A very important part of the [[aero.dat \| aero model]] in Silent Wings is the airfoil polars. The quality of the polar files has a large impact on the way the aircraft will fly and perform in the simulator.		A very important part of the [[aero.dat \| aero model]] in Silent Wings is the airfoil polars. The quality of the polar files has a large impact on the way the aircraft will fly and perform in the simulator.

Ola at 23:00, 5 March 2007

2007-03-05T23:00:52Z

← Older revision		Revision as of 23:00, 5 March 2007
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	A very important part of the aero model in Silent Wings is the airfoil polars. The quality of the polar files has a large impact on the way the aircraft will fly and perform in the simulator.		A very important part of the [[aero.dat \| aero model]] in Silent Wings is the airfoil polars. The quality of the polar files has a large impact on the way the aircraft will fly and perform in the simulator.

	You will get the highest quality polars from using data from wind tunnel tests. Unfortunately, these are not often available. The second-best option is then to use calculated polars. There are several freely available programs that can do this. For the Silent Wings aircraft, these two programs have been used:		You will get the highest quality polars from using data from wind tunnel tests. Unfortunately, these are not often available. The second-best option is then to use calculated polars. There are several freely available programs that can do this. For the Silent Wings aircraft, these two programs have been used:

Ola at 23:00, 5 March 2007

2007-03-05T23:00:17Z

@@ Line 10: / Line 10: @@
 == Single file polar format ==
-The easiest way to define a polar is to use the .polar file format. This is a single text file defining sets of polars with points for lift, drag and pitch moment as a function of angle of attack, at a fixed flap deflection. Here is an example, from a file called naca0012.polar, trimmed down for simplicity. It defines polars for 3 different flap deflections.
+The easiest way to define a polar is to use the .polar file format. This is a single text file defining sets of polars with points for lift, drag and pitch moment as a function of angle of attack, at a fixed flap deflection. Here is an example, from a file called naca0012.polar, trimmed down for simplicity. It defines polars for 3 different flap deflections. It is only necessary to define the angle of attack points that you have. The rest will be taken care of by the Silent Wings aero model.
   # Polar file for naca0012
@@ Line 57: / Line 57: @@
 == Multi-file polar format ==

Ola at 22:41, 5 March 2007

2007-03-05T22:41:02Z

← Older revision		Revision as of 22:41, 5 March 2007
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	}		}

	If you use X-Foil to generate the polars, you can use the small tool [xf2sw] to auto-generate the polar file.		If you use X-Foil to generate the polars, you can use the small tool [[xf2sw]] to auto-generate the polar file.

	== Multi-file polar format ==		== Multi-file polar format ==

Ola at 22:40, 5 March 2007

2007-03-05T22:40:38Z

← Older revision		Revision as of 22:40, 5 March 2007
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	}		}

	If you use X-Foil to generate the polars, you can use [xf2sw ~~\| this small tool~~] to auto-generate the polar file.		If you use X-Foil to generate the polars, you can use the small tool [xf2sw] to auto-generate the polar file.

	== Multi-file polar format ==		== Multi-file polar format ==

Ola at 22:39, 5 March 2007

2007-03-05T22:39:34Z

← Older revision		Revision as of 22:39, 5 March 2007
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	You will get the highest quality polars from using data from wind tunnel tests. Unfortunately, these are not often available. The second-best option is then to use calculated polars. There are several freely available programs that can do this. For the Silent Wings aircraft, these two programs have been used:		You will get the highest quality polars from using data from wind tunnel tests. Unfortunately, these are not often available. The second-best option is then to use calculated polars. There are several freely available programs that can do this. For the Silent Wings aircraft, these two programs have been used:

	* [http://web.mit.edu/drela/Public/web/xfoil/ \| X-Foil]		* [http://web.mit.edu/drela/Public/web/xfoil/ X-Foil]
	* [http://www.mh-aerotools.de/ \| Javafoil]		* [http://www.mh-aerotools.de/ Javafoil]

	X-Foil is the most advanced program, and the most difficult to use. ~~In the right hands,~~ it can ~~calculate rather~~ good ~~polars, in the wrong hand it won't~~.		X-Foil is the most advanced program, and the most difficult to use. Used correctly it can produce quite good results.

	== Single file polar format ==		== Single file polar format ==
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	}		}

			If you use X-Foil to generate the polars, you can use [xf2sw \| this small tool] to auto-generate the polar file.

	== Multi-file polar format ==		== Multi-file polar format ==

Ola at 22:37, 5 March 2007

2007-03-05T22:37:40Z

← Older revision		Revision as of 22:37, 5 March 2007
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	You will get the highest quality polars from using data from wind tunnel tests. Unfortunately, these are not often available. The second-best option is then to use calculated polars. There are several freely available programs that can do this. For the Silent Wings aircraft, these two programs have been used:		You will get the highest quality polars from using data from wind tunnel tests. Unfortunately, these are not often available. The second-best option is then to use calculated polars. There are several freely available programs that can do this. For the Silent Wings aircraft, these two programs have been used:

	* X-Foil		* [http://web.mit.edu/drela/Public/web/xfoil/ \| X-Foil]
	* Javafoil		* [http://www.mh-aerotools.de/ \| Javafoil]

	X-Foil is the most advanced program, and the most difficult to use. In the right hands, it can calculate rather good polars, in the wrong hand it won't.		X-Foil is the most advanced program, and the most difficult to use. In the right hands, it can calculate rather good polars, in the wrong hand it won't.

Ola at 22:36, 5 March 2007

2007-03-05T22:36:10Z

← Older revision		Revision as of 22:36, 5 March 2007
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			A very important part of the aero model in Silent Wings is the airfoil polars. The quality of the polar files has a large impact on the way the aircraft will fly and perform in the simulator.

			You will get the highest quality polars from using data from wind tunnel tests. Unfortunately, these are not often available. The second-best option is then to use calculated polars. There are several freely available programs that can do this. For the Silent Wings aircraft, these two programs have been used:

			* X-Foil
			* Javafoil

			X-Foil is the most advanced program, and the most difficult to use. In the right hands, it can calculate rather good polars, in the wrong hand it won't.

	== Single file polar format ==		== Single file polar format ==
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	p = [ 8.000 0.9101 0.012100 -0.0040 ]		p = [ 8.000 0.9101 0.012100 -0.0040 ]
	}		}



	== Multi-file polar format ==		== Multi-file polar format ==

Ola at 22:26, 5 March 2007

2007-03-05T22:26:07Z

← Older revision		Revision as of 22:26, 5 March 2007
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	The easiest way to define a polar is to use the .polar file format. This is a single text file defining sets of polars with points for lift, drag and pitch moment as a function of angle of attack, at a fixed flap deflection. Here is an example, from a file called naca0012.polar, trimmed down for simplicity.
			== Single file polar format ==

			The easiest way to define a polar is to use the .polar file format. This is a single text file defining sets of polars with points for lift, drag and pitch moment as a function of angle of attack, at a fixed flap deflection. Here is an example, from a file called naca0012.polar, trimmed down for simplicity. It defines polars for 3 different flap deflections.

	# Polar file for naca0012		# Polar file for naca0012
Line 42:		Line 45:
	p = [ 8.000 0.9101 0.012100 -0.0040 ]		p = [ 8.000 0.9101 0.012100 -0.0040 ]
	}		}


			== Multi-file polar format ==