When I say they are both valid, I mean they both help to achieve the goal even if into different ways and with different results.
We know YaSim can not accurately deal with high AoA situations or spins, so it would be a poor tool for a fighter jet or aerobatics plane which you frequently operate at the edge of the envelope.
Knüppelrührer wrote in Wed Dec 11, 2019 5:45 pm:From a scientific point of view jbsim is preferable. It works with forces and moments acting on masses so if everything correct all performance and handling items should fall into place and become realistic.
Is it possible to use Yasim to close some of these gaps?
For example flight testing a Yasim version and feeding derived coefficients into the Jbsim version.
For example flight testing a Yasim version and feeding derived coefficients into the Jbsim version.
Or is Aeromatic plus handtuning the way to go if no more detailed methods available?
To me only JSBSim aircraft exist, the rest is just eye-candy from people that are interested in creating a visual model that looks nice and then don't have the time to work on an FDM so they just patch some Yasim in them so that it pretends to fly.
asr wrote in Sun Dec 15, 2019 10:27 am:I just don't fly Yasim aircraft. Not a single one of them, even those who "seem" to be the most realistic, gets anywhere near what I expect from a flight sim.
asr wrote in Sun Dec 15, 2019 10:27 am:Everyone is entitled to its opinion.
asr wrote in Sun Dec 15, 2019 10:27 am:. It's tempting to those people that don't have the data/time/knowledge/interest in creating a realistic FDM.
asr wrote in Sun Dec 15, 2019 10:27 am: ... the rest is just eye-candy from people that are interested in creating a visual model that looks nice and then don't have the time to work on an FDM so they just patch some Yasim in them so that it pretends to fly.
msalama wrote in Fri May 15, 2020 4:34 am:Correct me if I'm wrong, but AFAIK Yasim doesn't model fixed-wing ground effect at all. And that's reason enough for me to prefer JSBsim A/C.
// Account for ground effect by multiplying the vertical force
// component by an amount linear with the fraction of the wingspan
// above the ground.
if ((_wingSpan != 0) && (_groundEffect != 0 ))
{
// distance between ground and wing ref. point
float dist = ground[3] - Math::dot3(ground, _geRefPoint);
float fz = 0;
float geForce[3] = {0, 0, 0};
if(dist > 0 && dist < _wingSpan) {
fz = Math::dot3(faero, ground);
fz *= (_wingSpan - dist) / _wingSpan;
fz *= _groundEffect;
Math::mul3(fz, ground, geForce);
_body.addForce(geForce);
}
if (_modelN != 0) {
_gefxN->setFloatValue(geForce[0]);
_gefyN->setFloatValue(geForce[1]);
_gefzN->setFloatValue(geForce[2]);
_wgdistN->setFloatValue(dist);
}
}
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