Hello, the question is difficult to answer as quite a number of questions is left open:
Do you have any algorithms you want to implement?
What is the size of the mesh within the 150 x 150 km area?
Do you have any preferences regarding the software that you intend to run?
...
Generally speaking, virtually 'any' PC with Windows should do. Or some Linux computer - eg. RPi. Regarding software, the situation is about the same: from Matlab to Python with all its packages or some other open source simulation software - virtually 'anything' should do. The most influential factor will be the number of nodes of your mesh, the amount of time available for each run - and the amount of money you are able resp. willing to spend.