Ground effect models

[seanmcleod70]

I've written up a brief description and comparison of 3 different ground effect models, one being a fairly common one found in a number of JSBSim aircraft like the 737 model, and another one being a Boeing supplied full simulator model for the 747-100 years ago for NASA Ames, and lastly an Airbus provided model for use in a challenge for developing a better autoland control system.

https://seanmcleod70.github.io/FlightDynamicsCalcs/GroundEffectModels.html

Hopefully it might be useful for JSBSim modelers looking to add or improve the ground effect model in their particular FDM.

[bcoconni]

Very interesting @seanmcleod70.

This gave me an idea and I have created a notebook on Google Colab where, following your inspiration, a simple aerodynamics model (using the Vortex Lattice Method) has been used to compute the ground effect on a basic 737 unswept wing.

Numerical computation of the ground effect - Google Colab.

Well, believe or not, the computations are in the same ballpark than JSBSim. Of course, my code most likely contain some bugs but I found this interesting nonetheless.

[agodemar]

@bcoconni very good discussion, thank you for sharing.
For the sake of completeness, I would add proper labels to the axes in your final plots: $h/b$, for x-axes; $k_{C_L,\mathrm{ge}}$ and $k_{C_D,\mathrm{ge}}$ for the y-axes.