Direct Numerical Simulation (DNS) is a computational method used to solve fluid dynamics problems by simulating the flow of fluids at a very detailed level. It involves solving the governing equations of fluid motion, specifically the Navier-Stokes equations, without any approximations. This allows for an accurate representation of complex flow structures and turbulence. DNS is particularly useful in research and engineering applications where understanding the fundamental behavior of fluid flows is essential. It requires significant computational resources due to the need for fine spatial and temporal resolution, making it suitable for studying small-scale phenomena in various fields, including aerospace engineering and meteorology.