GMICE (UK), AMASCE (US) & EIT (Canada)

I investigated erosion of an alluvial bed caused by a novel tidal turbine, via flume experiments. The turbine which is called Momentum Revsal Lift (MRL) turbine, is a new class of tidal turbines suitable for shallow water conditions. Following technical note, from the preliminary results, is under review with one of the renewable energy journals.​​


  • Ebrahimi, M., Duncan, S., Belmont, M.R., Kripakaran, Tabor, G., Djordjević, S. “Flume experiments on the impact of a cross-flow turbine on an erodible bed”.





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 did the experimental phase of the project in a 0.65m-wide recirculating flume. Pier/bridges blocked by debris were 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 journal article is published



Following conference papers are published 



with the following journal article being under review


  • Kahraman, R., Riella, M., Ebrahimi, M., Kripakaran, P., Djordjević, S., Tabor, G. “Prediction of free surface flow around a bridge pier: Influence of the Froude number.”

​Risk assessment of masonry bridges (RAMB) under flood conditions: hydrodynamic effects of debris blockage and scour

Centre for Water Systems, University of Exeter, United Kingdom

I did this project with Prof. Peyman Badiei. 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:


  • Ebrahimi, M. (2008). "Numerical modeling of deformation of alluvial bed in rapidly varied flow." MSc Thesis, University of Tehran, Iran (In Persian).
  • Ebrahimi, M., Badiei, P. (2008). “Simulation of sedimentation in trenches using a two-dimensional vertical numerical model.” Proc. 8th International Conference on Coasts, Ports, and Marine Structures, Tehran, Iran, November 2008, pp. 145-148.
  • Ebrahimi, M., Badiei, P. (2008). “Numerical simulation of sediment transport in a two-dimensional unsteady, rapid flow.” Proc. 4th National Conference of Civil Engineering, Tehran, Iran, Apr. 2008, Vol. 2 (In Persian).


MYPROJECTS

In this project, which was 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:



Flow patterns, bank erosion, and planimetric changes in meandering streams: an experimental study

River and Estuarine Morphodynamics Lab., Queen's University, Kingston, Canada

Specialised in River Engineering & Flood-Sediment-Bridge Interaction

Mohsen Ebrahimi

May 2015 - Oct 2018

Numerical modeling of 2D scour and trench migration in rapidly varied flow

Dept. of Civil Engineering, University of Tehran, Iran

Jan. 2009 - Jan. 2015

Jan. 2009 - Jan. 2013

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:


  • Laboratory experiments of flow patterns, bank erosion and planform evolution of meandering streams
  • Measurement of flow velocities using ADV's
  • Surveying morphological changes using conventional techniques and laser scanning
  • Data analysis and visualization


Based on the results, following articles were published



Impact of A NOVEL TIDAL TURBINE ON SEABED EROSION

Jan 2018 - Aug 2018

Sept. 2006 - Sept. 2008


Developing a cement-based method to stabilize sand in experimental tests

River and Estuarine Morphodynamics Lab., Queen's University, Kingston, Canada