Velocity and Turbulence Characteristics in Flows Through Rigid Vegetation
Laboratory experiments were conducted to investigate the velocity and turbulence characteristics in flows through rigid vegetation. The vegetation was simulated by an array of acrylic dowels mounted to the bed of a recirculating hydraulic flume. Velocity measurements were taken in both the longitudinal and vertical directions using a one-dimensional laser doppler velocimeter (LDV). Experiments were conducted under partially submerged, fully submerged and double layer flow conditions. The term double layer flow is used to describe flows that contain two different heights of vegetation. In each experiment, velocity and turbulence intensity profiles were taken at several different locations within the array.
Additional experiments were conducted to examine how bed and vegetative skin roughness influence the velocity and turbulence characteristics. Belt sander strips were glued to the bed of the flume to simulate bed roughness and adhesive sandpaper was attached to the dowels to simulate vegetative skin roughness. Finally, experiments were conducted to study sediment transport and deposition in flows containing vegetation.