The main objective of my research is to understand some of the fundamental properties of turbulence using the method of direct numerical simulation (DNS). DNS of turbulent flows is the numerical solution of the exact, three-dimensional, time-dependent Navier-Stokes equations. The direct solution, via DNS, of these equations, which govern the motion of Newtonian fluids, eliminates the closure problem and its inevitable empiricism.
Due to the limited memory and speed of current and near-future supercomputers (even the massively parallel machines) it is not expected that DNS will be able to predict engineering flows in complex geometries (e.g. the flow over an airplane or inside a combustor) in the foreseeable future. However, DNS will remain the only numerical method that can provide new physical insights at all scales of turbulence in flows involving complex physical phenomena such as chemically-reacting or particle-laden turbulent flows. This distinct capability of DNS is simply due to the absence of empiricism. Furthermore, DNS has already provided excellent agreement with measurements in wind tunnels at comparable values of the microscale Reynolds number. As the capabilities of parallel computing expand, DNS will be more widely used in scientific studies of complex physical phenomena in simple geometries.