Hi everyone!
I think I found a little bug in a couple of JSBSim-aircraft:
The property
/fdm/jsbsim/aero/coefficient/CDde (Drag_due_to_Elevator_Deflection)
takes negative values when the elevator moves up, so the elevator face is
accelerating the plane.
The wrong code is found in the <model>.xml file:
<product>
<property>aero/qbar-psf</property>
<property>metrics/Sw-sqft</property>
<property>fcs/elevator-pos-norm</property>
<value>0.059</value>
</product>
"fcs/elevator-pos-norm" should be turned to an absolute value by <abs> ..
</abs>
Here's an example of the bug's effect:
---------------------------
When you take the Lockheed1049 and let it fly close to stall speed, yoke
pulled all the way back,
the elevator generates a thrust of 13kN while each of the four engines only
deliver 5kN.
With the bug fixed, the engines are running at 11kN each.
---------------------------
A list of the compromised models:
----negative Drag----
707
737-300
747-400
A6M2-jsbsim
an2
Boeing314
Concorde
DC-6B
E3B
F80C
F-117
KC135
Lockheed1049
Malolo1
Noratlas
OV10_CDF
RafaleB17
Rascal110-JSBSim
T-4-jsbsim
YardStik
---------------------
The next list contains aircraft that have the bug,
but it doesn't take any effect because <elevator-pos-norm> is always zero.
(Who can tell me why?)
----zero Drag-----
A300
A380
colditz
MD11
paraglider
SaabJ35Draken
sgs233
victor
------------------
And the following planes seem to have buggy code, but I somehow couldn't
start their jsbsim-versions to test it:
---- ??? ----
HondaJet
Skyranger
MB326
-------------------
Am I right?
Regards, Andreas Zenner
------------------------------------------------------------------------------
Download Intel® Parallel Studio Eval
Try the new software tools for yourself. Speed compiling, find bugs
proactively, and fine-tune applications for parallel performance.
See why Intel Parallel Studio got high marks during beta.
http://p.sf.net/sfu/intel-sw-dev
_______________________________________________
Flightgear-devel mailing list
Flightgear-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/flightgear-devel
