 Integral length scale

The integral length scale is a concept from turbulence and fluid mechanics that characterizes the size of the large-scale eddies in a turbulent flow. It is a measure of the extent over which turbulent fluctuations are correlated. In other words, it provides an estimation of the spatial scale of the largest coherent structures present in a turbulent flow field. Mathematically, the integral length scale \(L\) can be defined using the correlation function of the velocity field in turbulence.