May 2015 - Present
This is an ongoing project for studying debris effects on hydrodynamics and scour at pier/bridges having a geometry similar to that of masonry bridges. I do the experimental phase of the project in a 0.65m-wide recirculating flume. Pier/bridges blocked by debris will be physically modelled to investigate debris effect on flow velocity pattern, scour and hydrodynamic pressure and forces. For further information, please refer to the project blog here.
Following conference papers are published
with the following journal artricles being under review
and in preparation stage
Sept. 2006 - Sept. 2008
Two cases of 2D vertical morphological changes in channel flows were simulated in this project. In the first case, scour in transition from a fixed-bed to an erodible bed was simulated, and the results were verified using available experimental data. In the second case, trench migration was simulated and results were validated using data from previous researchers. Simulations were carried out via programming in Fortran, where sediment transport and morphological modules were added into a previously developed non-hydrostatic current model with k-ε turbulence model.
In this project, sediment concentrations in the flow field were calculated via solving advection-diffusion equiation using finite volume method and time-splitting technique in a rectangular boundary fitted coordinate system. Advection equation was solved explicitly by the 1st-order backward scheme, and diffusion equation was solved implicitly using double-sweep algorithm. Boundary condition of sediment concentration at the bed was identified using the stochastic method introduced by van Rijn.
This project resulted in the following publications:
Jan. 2009 - Jan. 2015
Jan. 2009 - Jan. 2013
In this project, which was again carried out under constructive supervision of Professor Ana Maria da Silva, a method to fix movable beds in river-related laboratory research or physical model studies was proposed. The method avoids using harsh chemicals and ensures that the granular roughness of the original movable bed is maintained.
This methods uses sand-cement mixture for stabilizing the movable boundary, and is reported in the following articles:
This project, which was carried out under wonderful supervision of Professor Ana Maria da Silva, was a laboratory modeling of flow, bank erosion and planimetric changes in meandering streams. It aimed at 1) studying flow patterns in meandering streams; 2) evaluating existing equations for estimating bank erosion; and 3) providing insight into the planimetric fate of the meandering rivers. This included the following:
Based on the results, following papers were published
Several other articles are in preparation and submission stage.
Mohsen Ebrahimi © All rights reserved.