Though you’d likely get a more precise answer with a 3D viscous solver, a solution from an inviscid tool can still give you enough guidance to keep your development program chugging along. Due to needing to split a model into defined panels, you can get pretty creative with what kind of data you generate beyond the standard lift and drag curves.
For instance, you can calculate estimates of the lift distribution across a wing or tail. I often do this to provide mechanical engineering teams with the loads we expect the wing to see in flight—that is, the amount of force and bending moment they should design the wing to withstand.
Because any geometry is made up of individual panels, it’s straightforward to export the aero coefficient results for all panels and calculate the lift and moment of each panel separately. This helps avoid an overbuilt, and thus over-heavy, wing.
There are many more options for 3D inviscid tools than there are for 2D tools in general. Two that I’ve seen used most often are:
Athena Vortex Lattice, more commonly called AVL: A truly excellent, free vortex lattice solver. Just like XFOIL, it has good documentation to get you started. The command-line interface takes a little getting used to, but honestly this program can do so much it’s a little absurd it’s free.
AVL is the primary workhorse for my own aero work, in part because it uses text files for all inputs and outputs. This has let me write a suite of MATLAB scripts to fine-tune my geometry model and generate a large amount of data without as much manual effort. Doing extra coding really isn’t necessary though; the raw text files are easy enough to work with.
XFLR5: Another free solver that might be a better intro step for newcomers to panel methods. Unlike AVL, this software has a user interface that allows the user to create their geometry inside the program, instead of defining it in a separate file.
It also features viscous 2D analysis akin to XFOIL’s capabilities: any 3D analysis starts by running the desired airfoils at your expected Reynolds numbers. This data is then applied to the 3D model, increasing drag and allowing the user to see where the geometry could be expected to stall.
In my opinion, XFLR5 is more user-friendly than AVL, but trades that for some control and capability. I prefer being able to define my panels individually like in AVL. XFLR5 also tends to end its analyses at the very start of stall, when it can be helpful to have data beyond that. I like getting stall behavior data from XFOIL and manually adjusting the AVL results to match, since that stall region can be important for simulation purposes. But if you’d rather not put in all that extra effort and want to move faster with your analysis (and I really don’t blame you), XFLR5 is a nice all-in-one solver.
I definitely plan on testing XFLR5 out more though, and suggest you do similar before you decide which tool fits best in your workflow.