turbulence closure problem

The turbulence closure problem involves predicting how chaotic, swirling fluid motions (turbulence) influence the overall flow. Turbulence occurs at small scales within a fluid, making it difficult to directly simulate every tiny swirl. Instead, scientists use models called "closure schemes" to represent the effects of these small-scale motions on larger flows. This process "closes" the equations, allowing for practical calculations. Essentially, the problem is finding accurate ways to account for the energy and momentum transfer caused by turbulence without needing to resolve every minute detail.