I have some research papers on aircraft controller design that i want to simulate, but no system data is given in the research paper itself. I am also unable to find the aerodynamic data for any commercial/fighter aircraft anywhere. So i want to know where do the academic researchers get their data sets from? And is there some way for me to get trimmed or untrimmed aerodynamic data for my simulation?
I think I might get this question wrong, but if you are looking for aerodynamic characteristics and data of wing sections (aerodynamic profiles), we often use websites like Airfoiltools.com. You can also model and generate basic characteristics of chosen 2D shape in simple programs like XFOIL, or use XFLR5 by Mark Drela from MIT to extrapolate 2D characteristics to 3D shapes (wings and even whole airplanes with fuselage etc). If you are looking for data of already existing aircrafts you can try finding their "Operation Manual" / "User Manual".
P.S. For small models, flying with low speed = with low Reynolds numbers, the programs I mentioned are accurate enough, but for bigger airplanes they are too simplified