Atif Siddiqui | IIT Kharagpur (original) (raw)

Papers by Atif Siddiqui

Research paper thumbnail of Analysis of Open-Source Computational Fluids Dynamics Tool for Simulating Complex Hydrodynamic Problems

Research paper thumbnail of Analysis of Open-Source CFD Tools for Simulating Complex Hydrodynamic Problems

Volume 8: CFD and FSI, 2020

OpenFOAM (OF) represents an attractive and widely used open-source environment for simulating com... more OpenFOAM (OF) represents an attractive and widely used open-source environment for simulating complex hydrodynamic scenarios with several implemented numerical methods and wide variety of problems it can be applied to. For commercial and open-source solvers, though, expertise and experience are required to get physical and reliable results. Here, without pretending to be exhaustive, we aim to contribute in highlighting advantages and challenges of some key computational fluid dynamics (CFD)-simulation tools, with focus on the OF platform. We examine the effect of grid type, grid size and time-evolution scheme. Dynamic-mesh techniques and their influence on local and global numerical results are discussed, as well as the use of an overset grid versus a deforming mesh. Lastly, possible error sources in CFD simulations are discussed. These numerical studies are performed investigating two complex hydrodynamic problems: 1. a fully-immersed flapping hydrofoil aimed to generate thrust, 2....

Research paper thumbnail of Offshore Aquaculture in India: Site Considerations and Challenges in Indian Coastal Conditions

Oceanography & Fisheries Open access Journal

Offshore aquaculture is the practice of marine farming where the fish farm cages are placed furth... more Offshore aquaculture is the practice of marine farming where the fish farm cages are placed further from the shores into deeper ocean areas. This helps in increasing the size of farms, reduces danger of accidents with marine traffic and the waste from cage is easily washed away with stronger currents in the open ocean. One major disadvantage is that such a cage requires sophisticated technology and large investments. India has over 8000 km of coastline with great potential for development of mariculture. The exclusive economic zones which can extend up to at least 200 nautical miles from the coast, as shown in (Figure 1) (left), gives India a vast area for developing mariculture. Most of this potential remains underutilized as the locals and regional authorities lack the technical know-how and transfer of technology from academia to industry and local companies is extremely poor.

Research paper thumbnail of Dynamic Response of Axially Loaded Plates With Intermediate Fixities to Transient Hydrodynamic Impact Loads

Volume 9: Odd M. Faltinsen Honoring Symposium on Marine Hydrodynamics, 2013

Research paper thumbnail of PAPER ID SCEE-13-387

A dynamic analysis of axially loaded Timoshenko beams with intermediate fixities is presented. Th... more A dynamic analysis of axially loaded Timoshenko beams with intermediate fixities is presented. The underwater part of a craft is modeled as a flexible beam, which rises out and slams against the water at a large vertical velocity, causing highly localized hydrodynamic impact pressure moving at high velocities across the beam, setting it into high-frequency vibrations. The beam natural frequencies depend on the slenderness ratio, axial load, and end fixities. Increasing the axial tension and/or end fixity increases the natural frequencies, which are generated through Eigen analysis. Next, normal mode summation is used to analyze the impact-induced vibration response, which is generated for various impact speeds, deadrise angles, end fixities, axial loads, and slenderness ratios of the beam. A parametric study is done to predict the maximum dynamic stresses on the structure. The pressure is assumed to act at the equilibrium position. The aim is to study the dynamic stress configurations and draw conclusions leading to sound structural designs.

Conference Presentations by Atif Siddiqui

Research paper thumbnail of MTECH PRESENTATION

Research paper thumbnail of Analysis of Open-Source Computational Fluids Dynamics Tool for Simulating Complex Hydrodynamic Problems

Research paper thumbnail of Analysis of Open-Source CFD Tools for Simulating Complex Hydrodynamic Problems

Volume 8: CFD and FSI, 2020

OpenFOAM (OF) represents an attractive and widely used open-source environment for simulating com... more OpenFOAM (OF) represents an attractive and widely used open-source environment for simulating complex hydrodynamic scenarios with several implemented numerical methods and wide variety of problems it can be applied to. For commercial and open-source solvers, though, expertise and experience are required to get physical and reliable results. Here, without pretending to be exhaustive, we aim to contribute in highlighting advantages and challenges of some key computational fluid dynamics (CFD)-simulation tools, with focus on the OF platform. We examine the effect of grid type, grid size and time-evolution scheme. Dynamic-mesh techniques and their influence on local and global numerical results are discussed, as well as the use of an overset grid versus a deforming mesh. Lastly, possible error sources in CFD simulations are discussed. These numerical studies are performed investigating two complex hydrodynamic problems: 1. a fully-immersed flapping hydrofoil aimed to generate thrust, 2....

Research paper thumbnail of Offshore Aquaculture in India: Site Considerations and Challenges in Indian Coastal Conditions

Oceanography & Fisheries Open access Journal

Offshore aquaculture is the practice of marine farming where the fish farm cages are placed furth... more Offshore aquaculture is the practice of marine farming where the fish farm cages are placed further from the shores into deeper ocean areas. This helps in increasing the size of farms, reduces danger of accidents with marine traffic and the waste from cage is easily washed away with stronger currents in the open ocean. One major disadvantage is that such a cage requires sophisticated technology and large investments. India has over 8000 km of coastline with great potential for development of mariculture. The exclusive economic zones which can extend up to at least 200 nautical miles from the coast, as shown in (Figure 1) (left), gives India a vast area for developing mariculture. Most of this potential remains underutilized as the locals and regional authorities lack the technical know-how and transfer of technology from academia to industry and local companies is extremely poor.

Research paper thumbnail of Dynamic Response of Axially Loaded Plates With Intermediate Fixities to Transient Hydrodynamic Impact Loads

Volume 9: Odd M. Faltinsen Honoring Symposium on Marine Hydrodynamics, 2013

Research paper thumbnail of PAPER ID SCEE-13-387

A dynamic analysis of axially loaded Timoshenko beams with intermediate fixities is presented. Th... more A dynamic analysis of axially loaded Timoshenko beams with intermediate fixities is presented. The underwater part of a craft is modeled as a flexible beam, which rises out and slams against the water at a large vertical velocity, causing highly localized hydrodynamic impact pressure moving at high velocities across the beam, setting it into high-frequency vibrations. The beam natural frequencies depend on the slenderness ratio, axial load, and end fixities. Increasing the axial tension and/or end fixity increases the natural frequencies, which are generated through Eigen analysis. Next, normal mode summation is used to analyze the impact-induced vibration response, which is generated for various impact speeds, deadrise angles, end fixities, axial loads, and slenderness ratios of the beam. A parametric study is done to predict the maximum dynamic stresses on the structure. The pressure is assumed to act at the equilibrium position. The aim is to study the dynamic stress configurations and draw conclusions leading to sound structural designs.