I work at LLNL so I work with people who make cool simulations all the time. The coolest ones I’ve seen lately were the ones that helped with last year’s big fusion ignition shot at NIF.

There is a (very) recent article summarizing how simulations contributed to ignition here: https://www.llnl.gov/news/computing-codes-simulations-helped.... Just reading about how many different simulation teams were involved and how many different types of physics had to be modeled to get that shot to work is awe-inspiring, at least for me. Optimizing target thickness, modeling plasma in the target, laser coupling at the entrance hole, etc. - there are a ridiculous number of things that had to be modeled, together, at very different scales.

The prior article describing how simulation contributed to the pre-ignition, 1.3 MJ shot goes into some more detail and has some cool visualizations: https://lasers.llnl.gov/news/models-and-simulations-help-map.... The one showing the target fill tube perturbing the implosion in 3D stands out to me - it shows the types of tiny things that can cause a fusion shot to go wrong.