Flight Question Dll Vessel fly true

[TMHLIVE]

fly with him, and you will understand
Nautil

Nice Looking ship.

I took her for a test flight just around within atmo. in order to fly true i am pitching down -2 degrees with still the need to keep a eye on it depending on thrust. But ya thats pretty close but I think that the fact that 377 is basically a missile flying in atmo it needs a bit of a tweek to make it run right. But again love the ship. So alien like. Great lines and great work. I just don't think that the same number would apply. I'm no expert by any means. I just fly them

 

[Loru]

void VLiftCoeff (VESSEL *v, double aoa, double M, double Re, void *context, double *cl, double *cm, double *cd)
{
	int i;
	const int nabsc = 9;
	static const double AOA[nabsc] = {-180*RAD,-60*RAD,-30*RAD, -2*RAD, 15*RAD,20*RAD,25*RAD,60*RAD,180*RAD};
	static const double CL[nabsc]  = {       0,      0,   -0.4,      0,    0.7,     1,   0.8,     0,      0};
	[COLOR="Red"][B]static const double CM[nabsc]  = {       0,      0,  0.014, 0.0039, -0.006,-0.008,-0.010,     0,      0};[/B][/COLOR]
	for (i = 0; i < nabsc-1 && AOA[i+1] < aoa; i++);
	double f = (aoa-AOA[i]) / (AOA[i+1]-AOA[i]);
	*cl = CL[i] + (CL[i+1]-CL[i]) * f;  // aoa-dependent lift coefficient
	[COLOR="Red"][B]*cm = CM[i] + (CM[i+1]-CM[i]) * f;  // aoa-dependent moment coefficient[/B][/COLOR]
	double saoa = sin(aoa);
	double pd = 0.015 + 0.4*saoa*saoa;  // profile drag
	*cd = pd + oapiGetInducedDrag (*cl, 1.5, 0.7) + oapiGetWaveDrag (M, 0.75, 1.0, 1.1, 0.04);
	// profile drag + (lift-)induced drag + transonic/supersonic wave (compressibility) drag
}

 

[TMHLIVE]

I need to take up this stuff so I have a clue what all of it means. Don't try and explain it..I'm to dumb.

 

[gattispilot]

So the Cm needs to change. But to what?
That is the same for the Firefly

 

[Loru]

So the Cm needs to change. But to what?
That is the same for the Firefly

Change that way so they won't produce angular momentum?

 

[gattispilot]

Like this:

	static const double CM[nabsc]  = {       0,      0,  0.0, 0.0, 0,0,0,     0,      0};

He said changing what you did just made the elevators impossible to use.

 

[TMHLIVE]

here is what I sent to Gattispilot. I have also included the images I sent him. I am not sure if it helps diag the problem but I figured if it helps to get the problem fixed then every bit of info helps.

Thanks to everyone who has helped us with this problem
here is the email and images

This time I got pictures.

changing what you did just made the elevators impossible to use

these three images are from the same flight.

testflight 1

is me just cruising with very little power on and as you see it is dead center on the horizon but yet the cross above says im climbing. I have the speed set to where the v/s is very very slowly dropping. its is as close as i could get it.

test flight 2

I punched it for a bit. Notice my v/s climbed and so did my alt. But yet my ship is dead center. If i correct down to bring the cross level it will just go back up as thats what it wants to do

test flight 3

this image is a outer show. I have it paused but if you see the red line is angled down a bit. This leads me to believe that the engines are still causing lift when fired no matter what speed they are being fired at.

sorry about the big black space. I run more then one monitor and that one always shows up on a print screen for some reason

 

[Loru]

Ok. There are 2 phenomena here that needs to be explained - one is pitching because of momentum created by wing and second is ship gaining altitude because of lift figure.

First has been solved but for the second you need to tune lift down or play with drag.
(page 15 of API guide) (velocity vector you're seeing moving up is caused by second phenomenon)

As for elevators they're in separate bit of code so not sure how they stopped working.

 

[TMHLIVE]

Ok. There are 2 phenomena here that needs to be explained - one is pitching because of momentum created by wing and second is ship gaining altitude because of lift figure.

First has been solved but for the second you need to tune lift down or play with drag.
(page 15 of API guide) (velocity vector you're seeing moving up is caused by second phenomenon)

As for elevators they're in separate bit of code so not sure how they stopped working.

they didn't shop working trust me. The very slightest movement and I was out of control almost. I had to quickly null it out and recover before trying another setting.

 

[Loru]

I have no idea how control surfaces are implemented here (along with RCS). Maybe RCS is too powerfull, maybe controls are too big. :shrug:

I forward advice I've recieved: strip down ship from any aerodynamics and implement one from scratch. Then tune it, tune it and tune it. There is a reason aerospace industry pumps millions into wind tunels and simulations. It does not depend on single variable.

 

[TMHLIVE]

Gotta love the money