Mohanna Tajnesaie - Academia.edu (original) (raw)

Papers by Mohanna Tajnesaie

Research paper thumbnail of Two‐ and three‐dimensional multiphase mesh‐free particle modeling of transitional landslide with <i>μ</i>(<i>I</i>) rheology

International journal for numerical methods in fluids, Feb 12, 2024

Research paper thumbnail of Application of Computational Fluid Dynamics for Modeling of Secondary Flow Cells in Trapezoidal Channel

Fire field modelling (Computation Fluid Dynamics) has become more and more attractive as a critic... more Fire field modelling (Computation Fluid Dynamics) has become more and more attractive as a critical design tool to meet Performance-based fire design on advanced modern buildings. This paper describes the application of Computational Fluid Dynamics (CFD) to predict velocities and temperature distributions induced by a fire in a Steckler's experimental data [1]. The experimental data of different fire loads is taken as case study for present investigation. The experiments of Steckler's compartment fire were conducted to investigate fire-induced flows through the opening in a compartment of size 2.8 m × 2.8 m × 2.18 m (height). The compartment has a doorway opening of 0.74 m × 1.83 m to account the ventilation condition. A porous gas burner is flushed at the floor in the centre of the room with the diameter of 0.3m in the compartment. With the above experimental data, simulation studies were performed with combustion modelling using commercial code of ANSYS CFX-5. The comparison of simulation results of fire field models with experimental domain for different strengths of fire 31.6, 62.9, 105.3 and 158.0 kW is reported. The boundary conditions of the simulation are kept constant, only fire strength is changed to see the performance of the CFD tool. The door centreline temperature, velocities and room corner temperatures are predicted and compared with experimental data as well as with FDS. The results are in good agreement with the experimental data.

Research paper thumbnail of Numerical Modeling of Secondary Current Cells in Trapezoidal Channels with Uniform Roughness

Journal of Modeling in Engineering, Apr 15, 2010

Research paper thumbnail of Meshfree particle numerical modelling of sub-aerial and submerged landslides

Computers & Fluids, 2018

A novel multiphase mesh-free particle numerical model is developed and applied for modeling of su... more A novel multiphase mesh-free particle numerical model is developed and applied for modeling of sub-aerial (dry) and submerge (underwater) landslides. The model is based on the weakly-compressible moving particle semi-implicit method (WC-MPS), and treats the multiphase system of water and granular materials as a multi-density multi-viscosity continuum. The viscous behaviour of the granular material is predicted using a visco-plastic rheological model (i.e. µ(I)) with a dynamic inter-grain mechanical pressure. The model is validated and evaluated for the rigid, sub-aerial and submerged landslides in comparison with the available experimental measurements and past numerical results. The granular surface profile and the evolution of the granular mass are compared. Comparisons show a good agreement between the results of the developed model and those of the experiments, and also a better accuracy comparing to the past numerical studies. The results also show the capability of the model in dealing with the shape evolution and the deformation and fragmentation of granular interface. Complementary experiments on the sub-aerial landslide are also conducted to study the relevant physics and validate the model. The role of the rheological model is also investigated. Comparing the µ(I) rheology with the widely-used Herschel-Bulkley model shows a slightly more accurate granular profiles for the µ(I) rheology, for both sub-aerial and submerged landslides.

Research paper thumbnail of Numerical Modeling of water-waves induced by landslides with WC-MPS method

Journal of Dam and Hydroelectric Powerplant, Apr 10, 2020

Research paper thumbnail of Two and Three-Dimensional Multiphase Mesh-Free Particle Modeling of Transitional Landslide with Μ(I) Rheology

Research paper thumbnail of Discussion of “An approach for prediction of flood hydrograph at outlet of an ungauged basin using modified dynamic wave model by Biswadeep Bharali and Utpal Kumar Misra (2021)

ISH Journal of Hydraulic Engineering, 2021

Research paper thumbnail of Performance comparison of four turbulence models for modeling of secondary flow cells in simple trapezoidal channels

ISH Journal of Hydraulic Engineering

Due to the importance of channel flow characteristics in the water conveyance, the study of it is... more Due to the importance of channel flow characteristics in the water conveyance, the study of it is a noteworthy problem for hydraulics experts and much attempts has been accomplished for the modeling of the flow characteristics. One significant problem in this respect is the secondary-flow cells and their effect on flow specifications. Widespread experimental and analytical investigations have been accomplished on this phenomenon. However, researchers are trying to replace the expensive and time-consuming experimental approaches and ad-hoc analytical models with numerical simulation procedures using computational fluid dynamics (CFD). Selection of the proper turbulence model is one of the most important problems for this type of the numerical modeling. In the present study, after evaluating several turbulence models including k −ε , Shear Stress Transport (SST) and three versions of the Reynolds Stress Model (RSM) (i.e. LRR-IP, LRR-QI and SSG models), for the numerical simulation of the secondary-flow cells and their effects on trapezoidal channels flow, the more efficient model was selected. Available experimental data and theoretical model was used to validate the selected turbulence model. The results were validated in terms of the free water surface, depth-averaged velocity, and boundary shear stress. The results confirmed the performance and efficiency of SSG version of the Reynolds stress model for the numerical modeling of the secondary-flow cells.

Research paper thumbnail of Two‐ and three‐dimensional multiphase mesh‐free particle modeling of transitional landslide with <i>μ</i>(<i>I</i>) rheology

International journal for numerical methods in fluids, Feb 12, 2024

Research paper thumbnail of Application of Computational Fluid Dynamics for Modeling of Secondary Flow Cells in Trapezoidal Channel

Fire field modelling (Computation Fluid Dynamics) has become more and more attractive as a critic... more Fire field modelling (Computation Fluid Dynamics) has become more and more attractive as a critical design tool to meet Performance-based fire design on advanced modern buildings. This paper describes the application of Computational Fluid Dynamics (CFD) to predict velocities and temperature distributions induced by a fire in a Steckler's experimental data [1]. The experimental data of different fire loads is taken as case study for present investigation. The experiments of Steckler's compartment fire were conducted to investigate fire-induced flows through the opening in a compartment of size 2.8 m × 2.8 m × 2.18 m (height). The compartment has a doorway opening of 0.74 m × 1.83 m to account the ventilation condition. A porous gas burner is flushed at the floor in the centre of the room with the diameter of 0.3m in the compartment. With the above experimental data, simulation studies were performed with combustion modelling using commercial code of ANSYS CFX-5. The comparison of simulation results of fire field models with experimental domain for different strengths of fire 31.6, 62.9, 105.3 and 158.0 kW is reported. The boundary conditions of the simulation are kept constant, only fire strength is changed to see the performance of the CFD tool. The door centreline temperature, velocities and room corner temperatures are predicted and compared with experimental data as well as with FDS. The results are in good agreement with the experimental data.

Research paper thumbnail of Numerical Modeling of Secondary Current Cells in Trapezoidal Channels with Uniform Roughness

Journal of Modeling in Engineering, Apr 15, 2010

Research paper thumbnail of Meshfree particle numerical modelling of sub-aerial and submerged landslides

Computers & Fluids, 2018

A novel multiphase mesh-free particle numerical model is developed and applied for modeling of su... more A novel multiphase mesh-free particle numerical model is developed and applied for modeling of sub-aerial (dry) and submerge (underwater) landslides. The model is based on the weakly-compressible moving particle semi-implicit method (WC-MPS), and treats the multiphase system of water and granular materials as a multi-density multi-viscosity continuum. The viscous behaviour of the granular material is predicted using a visco-plastic rheological model (i.e. µ(I)) with a dynamic inter-grain mechanical pressure. The model is validated and evaluated for the rigid, sub-aerial and submerged landslides in comparison with the available experimental measurements and past numerical results. The granular surface profile and the evolution of the granular mass are compared. Comparisons show a good agreement between the results of the developed model and those of the experiments, and also a better accuracy comparing to the past numerical studies. The results also show the capability of the model in dealing with the shape evolution and the deformation and fragmentation of granular interface. Complementary experiments on the sub-aerial landslide are also conducted to study the relevant physics and validate the model. The role of the rheological model is also investigated. Comparing the µ(I) rheology with the widely-used Herschel-Bulkley model shows a slightly more accurate granular profiles for the µ(I) rheology, for both sub-aerial and submerged landslides.

Research paper thumbnail of Numerical Modeling of water-waves induced by landslides with WC-MPS method

Journal of Dam and Hydroelectric Powerplant, Apr 10, 2020

Research paper thumbnail of Two and Three-Dimensional Multiphase Mesh-Free Particle Modeling of Transitional Landslide with Μ(I) Rheology

Research paper thumbnail of Discussion of “An approach for prediction of flood hydrograph at outlet of an ungauged basin using modified dynamic wave model by Biswadeep Bharali and Utpal Kumar Misra (2021)

ISH Journal of Hydraulic Engineering, 2021

Research paper thumbnail of Performance comparison of four turbulence models for modeling of secondary flow cells in simple trapezoidal channels

ISH Journal of Hydraulic Engineering

Due to the importance of channel flow characteristics in the water conveyance, the study of it is... more Due to the importance of channel flow characteristics in the water conveyance, the study of it is a noteworthy problem for hydraulics experts and much attempts has been accomplished for the modeling of the flow characteristics. One significant problem in this respect is the secondary-flow cells and their effect on flow specifications. Widespread experimental and analytical investigations have been accomplished on this phenomenon. However, researchers are trying to replace the expensive and time-consuming experimental approaches and ad-hoc analytical models with numerical simulation procedures using computational fluid dynamics (CFD). Selection of the proper turbulence model is one of the most important problems for this type of the numerical modeling. In the present study, after evaluating several turbulence models including k −ε , Shear Stress Transport (SST) and three versions of the Reynolds Stress Model (RSM) (i.e. LRR-IP, LRR-QI and SSG models), for the numerical simulation of the secondary-flow cells and their effects on trapezoidal channels flow, the more efficient model was selected. Available experimental data and theoretical model was used to validate the selected turbulence model. The results were validated in terms of the free water surface, depth-averaged velocity, and boundary shear stress. The results confirmed the performance and efficiency of SSG version of the Reynolds stress model for the numerical modeling of the secondary-flow cells.