VSP AERO Parameters explained

[Sami Atris]

Hello Guys,

i checked all the Inputs that are possible in VSPAERO and there are some left, that i dont understand. Could you tell me what they mean?

1. Overview --> Moment Reference Position: What can I set here and what does Calc CG mean?
2. Advanced --> Batch calculation: does it calculate the thrust?

3. Advanced --> Cp Slicer: What does it do and how does it work?

4. Rotor --> What is the hub Diameter?
5. Control Grouping --> if I unterstand correctly you can define flaps and so on as a Group. What benefit does this give for the calculation?
6. Viewer Console --> What does it Show? And how is it different from the console on top of the button Launch Solver?

Thank you very much for your answers. I appreciate your help a lot.

[Rob McDonald]

> i checked all the Inputs that are possible in VSPAERO and there are some
> left, that i dont understand. Could you tell me what they mean?
>
> 1. Overview --> Moment Reference Position: What can I set here and what does
> Calc CG mean?

When calculating moments, you must always take them about some
reference point. You can specify this point manually, or you can use
OpenVSP's Mass Properties calculator to calculate it based on some Set
of components.

> 2. Advanced --> Batch calculation: does it calculate the thrust?

This has nothing to do with thrust. If you are running a sweep of
runs -- say three angles of attach -- this switch determines how
OpenVSP launches VSPAERO. The choices are once, with three alphas, or
three times, each with one alpha. The first approach is faster. The
second approach allows OpenVSP to plot results as they become
available.

> 3. Advanced --> Cp Slicer: What does it do and how does it work?

This will 'slice' the final solution along some plane and will produce
a line-plot of Cp on the surface cut by that plane. Add the planes
you want (typically y=constant planes) and then either calculate the
cuts for an existing solution, or re-run VSPAERO and the slices will
happen automatically.

> 4. Rotor --> What is the hub Diameter?

When using the Conway approach to an actuator disk, it will drop the
influence of the center of the disk up to a hub radius.

> 5. Control Grouping --> if I unterstand correctly you can define flaps and
> so on as a Group. What benefit does this give for the calculation?

It allows you to group individual control surfaces to a single
control. Easiest example of this is aileron. Left and Right wing
each have a control, their positive deflection direction is determined
by right hand rule with thumb running root to tip. So, TE down on
right with, TE up on left wing. By grouping them, you get control
influence of deflecting both as one 'control'.

Another example is an elevator. Same setup as before (two elevator
halves). Except you want to group them such that both deflect in the
same direction. By setting the gain on one to -1, we reverse its
direction and you get both sides of an elevator moving together.

For a flying with with many control effectors, this can be used to
group and schedule them as desired.

> 6. Viewer Console --> What does it Show? And how is it different from the
> console on top of the button Launch Solver?

Same idea -- but the Solver one reports whatever is output by the
solver. The Viewer one outputs whatever is written out when you click
'Launch Viewer'

Rob

[Sami Atris]

Mr. McDonald allthough I am not finished asking you questions I want to take this opportunity to thank you.

OpenVSP and VSPAERO are amazing Tools. But what is even more amazing is the fact that you take time for people with little knowledge like me. I am asking so many questions and you always answer pretty fast even if it is a lot to write. This really helps me finishing my Thesis about VSPAERO. I really apreciate your work a lot. Thank you very much Mr. McDonald.

[Sami Atris]

I am sry I am overwatched two Parameters.

1. Advanced --> What is the max turning Angle?
2. Advanced --> What is Far Field Dist?