Predicting Mean Flow Through an Array of Cylinders

The present paper develops a new framework to predict the mean flow through an array of cylinders in which the flow around the array (array-scale) and the flow around individual cylinders (element-scale) are modeled separately using actuator disc theory and empirical drag models respectively, and then coupled through the net drag force. Applying this framework only requires knowledge of the array geometry and incident flow. The framework is validated using high-fidelity direct numerical simulations for arrays of between 7 and 109 cylinders having different arrangements (staggered, concentric, random) and bounding shapes (circular, square) in both two- and three-dimensional flows. In general, the framework outperforms existing models which require calibration and are only valid for part of the practical parameter space. The demonstrated scale separation suggests different combinations of element-scale and array-scale models/theories may be used for other arrangements of bluff bodies.