A series of 18 flume runs were conducted in a 6-m long, 0.5-m wide recirculating flume with a bed gradient of 0.8% to determine the influence of obstruction shape on the formation and characteristics of forced pools. Six differentshaped obstructions were added to the flume with the maximum width of the obstruction held constant at 20 cm, which equaled a 40% constriction of flow. The obstruction...

In accordance with the problem of the need for calculation formula of the straight wall flume flow in open channel by experiment, the method of thee boundary layer is proposed; Analysis with boundary layer displacement thickness is studied, and the energy equation, continuous equation and the theory and critical depth of flume flow coefficient, velocity coefficient is deduced using the boundary...

We present an experimental study of the statistics of surface gravity wave turbulence in a flume of a horizontal size 12 x 6 m. For a wide range of amplitudes the wave energy spectrum was found to scale as Eomega approximately omega(-nu) in a frequency range of up to one decade. However, nu appears to be nonuniversal: it depends on the wave intensity and ranges from about 6 to 4. We discuss our...

Currently a new wave flume for hydraulic experiments near to prototype scale is under construction at Deltares. In the flume, modern measurement equipment will be installed. One of the potential sensor techniques is Terrestrial Laser Scanner (TLS) based range measurements of water waves. TLS range measurements are a very fast and accurate method for solid surfaces, providing temporal and spatia...

In a set of streamside mesocosms, stream ecosystem respiration (ER) increased with biofilm biomass and flow heterogeneity (turbulence) generated by impermeable bed forms, even though those bed forms had no hyporheic exchange. Two streamside flumes with gravel beds (single layer of gravel) were operated in parallel. The first flume had no bed forms, and the second flume had 10 cmhigh dune-shaped...

Flume studies have been carried out to investigate flow structure for relatively low velocities and inundation for vegetation typical to floodplains and wetlands, such as grasses and bushes. Mean velocity profiles and turbulence characteristics from flume experiments on three different natural vegetal roughness types are reported. Two relatively new approaches for describing vertical velocity p...

Standard postharvest unit operations that rely on copious water contact, such as fruit unloading and washing, approach the criteria for a true critical control point in fresh tomato production. Performance data for approved sanitizers that reflect commercial systems are needed to set standards for audit compliance. This study was conducted to evaluate the efficacy of chlorine dioxide (ClO(2)) ...