Mean Velocity Modeling of Open-Channel Flow with Submerged Rigid Vegetation
نویسندگان
چکیده
Abstract—Vegetation affects the mean and turbulent flow structure. It may increase flood risks and sediment transport. Therefore, it is important to develop analytical approaches for the bed shear stress on vegetated bed, to predict resistance caused by vegetation. In the recent years, experimental and numerical models have both been developed to model the effects of submerged vegetation on open-channel flow. In this paper, different analytic models are compared and tested using the criteria of deviation, to explore their capacity for predicting the mean velocity and select the suitable one that will be applied in real case of rivers. The comparison between the measured data in vegetated flume and simulated mean velocities indicated, a good performance, in the case of rigid vegetation, whereas, Huthoff model shows the best agreement with a high coefficient of determination (R=80%) and the smallest error in the prediction of the average velocities.
منابع مشابه
Vertical Velocity Distribution in Open-Channel Flow with Rigid Vegetation
In order to experimentally investigate the effects of rigid vegetation on the characteristics of flow, the vegetations were modeled by rigid cylindrical rod. Flow field is measured under the conditions of submerged rigid rod in flume with single layer and double layer vegetations. Experiments were performed for various spacings of the rigid rods. The vegetation models were aligned with the appr...
متن کاملMean and turbulent velocity fields near rigid and flexible plants and the implications for deposition
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. [1] The transport of fine sediment and organic matter plays an important role in the nutrient dynamics of shallow a...
متن کاملHydrodynamic characteristics of submerged vegetation flow with non-constant vertical porosity
In order to investigate the influence of the vertical variation of porosity on open-channel flow with submerged vegetation, vertical non-homogeneous stumps and stems in submerged vegetation flow are simulated with truncated cones in a laboratory flume. First, porosity is defined as a function of water depth. A new governing equation for vegetation flow is established on the basis of the poroela...
متن کاملA phenomenological model for the flow resistance over submerged vegetation
[1] The bulk velocity Ub in streams is conventionally estimated from Manning’s equation, but difficulties remain in parameterizing the roughness coefficient n when the streambed is covered with vegetation. A two-layer velocity model is proposed to determine n and Ub for the submerged vegetation case. The modeled n is derived as a function of flow and vegetation properties that can be inferred f...
متن کاملLarge Eddy Simulation of Fully-Developed Turbulent Flow Through Submerged Vegetation
Large Eddy Simulations (LES) are performed for an open channel flow through submerged vegetation with a water depth (h) to plant height (hp) ratio of h/hp=1.5 according to the experimental configuration of Fairbanks and Diplas (1998). Fairbanks and Diplas measured longitudinal and vertical velocities as well as turbulence intensities along several verticals in the flow and the data are used for...
متن کامل