Monitor outputs

[juddmehr]

I'm currently saving forces on wings in custom frames via the calc_aerodynamicforce() and decompose() functions in FLOWUnsteady (combined with _addsolution() from FLOWVLM). I need to do a similar thing, but with velocities on the wings. Are there functions already in place that allow for that?

[EdoAlvarezR]

If I understand correctly, you are trying to obtain the effective velocity along the wing and decompose into arbitrary direction, right?

For debugging purposes, I exposed the effective velocities used in the force calculation in calc_aerodynamicforce(...) through the optional argument Vout. Notice in Line 81 that if Vout is different than nothing, it will push to it an array with the vectors of the VPM-induced velocity (wake and embedded particles), VLM-induced velocity, freestream, and local kinematic velocity, all evaluated at the mid-point of the three bound vortices that make each horseshoe (TE to 1/4 chord, lifting line at 1/4 chord, and 1/4 chord to TE).

Hence, unfolding the two for loops around Line 81, Vout[j][k] is a 3-element array corresponding to one of the velocities (k==1 => VPM-induced, k==2 => VLM-induced, k==3 => Vinf, k==4 => Vkinematic), evaluated at the mid point of the l-th bound vortex of the i-th horseshoe of vlm_system, where l = (j-1)%3 + 1 and i = floor(Int, (j-1)/3 + 1).

For example, to get the total velocity that was used to calculate the aerodynamic force at each segment of the lifting line:

Veff = []

for j in 1:3*vlm.get_m(vlm_system)

    l = (j-1)%3 + 1

    if l == 2
         push!(Veff, Vout[j][1] .+ Vout[j][2] .+ Vout[j][3] .+ Vout[j][4])
    end

end

Then you can use decompose(...) to decompose all the vectors into a different coordinate system.

[juddmehr]

Just a note on your example loop above: In a monitor where you pass in the simulation object, you're going to want to use sim.vehicle.vlm_system, unless you've already assigned that as the variable vlm_system in the extra runtime function.