Direct Numerical Simulations of Flow Past Random Distributed Roughness

摘要

DNS is a useful tool for examining near-field flow details that may be hard to capture using experimental techniques. Knowledge of the near-field details is crucial to understanding transient growth and bypass transition. For the cylindrical roughness elements, the DNS method shows good agreement with both experiments and alternate DNS once a high resolution simulation is performed. This is very important because the DNS used currently for the quasi-random distributed roughness is also used by Doolittle5 and the current high resolution simulation. The experiments performed in the water channel also show good agreement in both downstream velocity measurements and collar vortex structures.