The term Numerical Relativity (NR) is used for mathematically modeling General Relativity-sensitive scenarios using Numerical methods, inevitably requiring computers to carry out. Numerical methods can solve problems involving equations for which no one has found analytical solutions (e.g., if they don't exist), and general relativity problems often have such equations. As such, numerical relativity can be considered one type of Computational Astrophysics. Example scenarios include close interactions, such as mergers between Compact Objects, i.e., involving Strong-Field Gravity.
The numerical calculations of Black Hole Merger scenarios were critical in recognizing the likely causes of the recently-recorded Gravitational Wave events.