X-Plane

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GESchwarz

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So with X-Plane I understand that you can create a model of your design and fly it in the computer. How do you do that? Does it give you CAD capability? Do you punch in all the numbers and it creates it for you mathematically or what? I heard that you have to pay the people at X-Plane to create the model for you. What's the deal?
 

Topaz

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The subject of X-Plane has been discussed quite a lot here. A search will turn that material up.

As for how you input the aircraft, I believe that's done numerically - and quite a number of experienced X-plane users have said that you have to "tweak" the inputs to make the airplane fly "right" in X-Plane.
 

BBerson

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X-Plane comes with PlaneMaker. You can build a virtual plane from scratch, but it's much easier to take an existing design and modify it, then press save and presto you have a new design.
Definitely a useful tool. It has some limitations and of course it isn't real. It can't model wing stall behavior, for example.
 

Radicaldude1234

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So with X-Plane I understand that you can create a model of your design and fly it in the computer. How do you do that? Does it give you CAD capability? Do you punch in all the numbers and it creates it for you mathematically or what? I heard that you have to pay the people at X-Plane to create the model for you. What's the deal?
Well, its been awhile, but the process is described here in these tutorials: PlaneMaker Tutorials - YouTube

Don't need to pay the fine people at X-Plane (I doubt they'll make you a plane even if you offer payment). The gist of it is:

1. You pick or create your own airfoil for your flying surfaces. For the latter, all you have to do is approximate the shape and the Cl vs Alpha curve.
2. You then approximate the wing planform by specifying said wing in sections. In these sections you can specify the chord-length, sweep/taper, and dihedral.
3. The fuselage is approximated in about the same way, using sections, where you use polygons (usually octagons or hexagons).
4. The engine type and position is specified. For prop planes, it will simulate left (or right) turning tendencies.
5. For control surfaces, you can specify the length, chord, and some other nifty features, like ailerons that droop with flaps.
6. Landing gear can also be simulated, including the retracting variety, changing drag and stability when extended.
7. For stability stuff, you can input the moments of inertia, static margin, and a lot of other stuff I'm forgetting.

If you do all that, the sim code will generate the rest of the behavior.

What I've found was:

1. It doesn't simulate cowlings well, so drag will probably be on the conservative side.
2. Stalls and spins aren't simulated well. I couldn't get anything to spin at all. Stalls involve just mushing a long and descending.
3. I would trust it in terms of determining rough handling characteristics on the linear part of the Cl vs Alpha curve.
4. You can turn on visual representation of forces to better understand how the lift loads change in different configurations.

The Do-335 I did in X-Plane 9. I'd imagine that XP-10 is even better in terms of simulation:

2011_0530_Xplane.jpg2011_0530_Xplane2.jpg2011_0530_Xplane3.jpg2011_0530_Xplane4.jpg2011_0603_Xplane.jpg

Thoughts?
 

Radicaldude1234

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clanon

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In the old times(xplane v7.x) you could build it through AirplanePDQ and then export it to xplane.
Or the other way around if you want.
 
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