Engineering & Applied Science / Mechanical Engr PhD Dissertation Defense by Mr. Ashish Pathak
When: Thursday,
March 23, 2017
2:30 PM
-
4:30 PM
Where: Textiles Building 101E
Description: Engineering & Applied Science (EAS) /
Mechanical Engineering (MNE)
PhD Dissertation Defense by Mr. Ashish Pathak
March 23, 2017
2:30 p.m. 4:30 p.m.
Textile Building, Room 101E
TOPIC:
An Advanced 3D Computational Framework for Simulating Fluid-Structure Interaction in two-fluid Flows: Application in Ocean Wave Energy Conversion Technology
ABSTRACT:
Wave energy converter (WEC) devices harness the renewable ocean wave energy and convert it into useful forms of energy, e.g., mechanical or electrical. In this dissertation an advanced 3D computational framework is presented to study the interaction between water waves and WEC devices. The computational tool solves the full Navier-Stokes equations and considers all important effects impacting the device performance. To enable large-scale simulations in fast turnaround times, the computational solver was developed in an MPI parallel framework. A fast multigrid preconditioned solver is introduced to solve the computationally expensive pressure Poisson equation. Simulating a floating object, representative of WECs, interacting with two fluids having high density ratio is a challenging problem for computational fluid dynamics (CFD) solvers. Special schemes were implemented to ensure robustness and numerical stability of the solver in handling such cases and a wide range of other problems. Since the wave energy is concentrated near the water free surface, the emphasis lately has been on the study of surface piercing WEC devices. A novel three-phase reconstruction algorithm was developed to enable such studies via numerical simulations. The constituent components of the proposed solver was validated against benchmark problems. The solver was then applied to a bottom-hinged flap-type WEC oscillating due to water waves. The numerical WEC response and water free surface dynamics were compared with experimental time series data and a good agreement was found. Additional simulations were conducted to investigate the applicability of Froude scaling in predicting full scale WEC response from the model experiments.
ADVISOR:
Dr. Mehdi Raessi
Department of Mechanical Engineering
COMMITTEE MEMBERS:
Dr. Mehdi Raessi, Department of Mechanical Engineering
Dr. Gaurav Khanna, Department of Physics / Program Director, EAS
Dr. Raymond Laoulache, Department of Mechanical Engineering
Dr. Geoff Cowles, SMAST / Fisheries Oceanography
Open to the public.
All MNE / EAS students are encouraged to attend.
For more information, please contact Dr. Mehdi Raessi:
(mraessi@umassd.edu, 508-999-8496)
Thank you,
Sue Cunha, Administrative Assistant
scunha@umassd.edu
Mechanical Engineering (MNE)
PhD Dissertation Defense by Mr. Ashish Pathak
March 23, 2017
2:30 p.m. 4:30 p.m.
Textile Building, Room 101E
TOPIC:
An Advanced 3D Computational Framework for Simulating Fluid-Structure Interaction in two-fluid Flows: Application in Ocean Wave Energy Conversion Technology
ABSTRACT:
Wave energy converter (WEC) devices harness the renewable ocean wave energy and convert it into useful forms of energy, e.g., mechanical or electrical. In this dissertation an advanced 3D computational framework is presented to study the interaction between water waves and WEC devices. The computational tool solves the full Navier-Stokes equations and considers all important effects impacting the device performance. To enable large-scale simulations in fast turnaround times, the computational solver was developed in an MPI parallel framework. A fast multigrid preconditioned solver is introduced to solve the computationally expensive pressure Poisson equation. Simulating a floating object, representative of WECs, interacting with two fluids having high density ratio is a challenging problem for computational fluid dynamics (CFD) solvers. Special schemes were implemented to ensure robustness and numerical stability of the solver in handling such cases and a wide range of other problems. Since the wave energy is concentrated near the water free surface, the emphasis lately has been on the study of surface piercing WEC devices. A novel three-phase reconstruction algorithm was developed to enable such studies via numerical simulations. The constituent components of the proposed solver was validated against benchmark problems. The solver was then applied to a bottom-hinged flap-type WEC oscillating due to water waves. The numerical WEC response and water free surface dynamics were compared with experimental time series data and a good agreement was found. Additional simulations were conducted to investigate the applicability of Froude scaling in predicting full scale WEC response from the model experiments.
ADVISOR:
Dr. Mehdi Raessi
Department of Mechanical Engineering
COMMITTEE MEMBERS:
Dr. Mehdi Raessi, Department of Mechanical Engineering
Dr. Gaurav Khanna, Department of Physics / Program Director, EAS
Dr. Raymond Laoulache, Department of Mechanical Engineering
Dr. Geoff Cowles, SMAST / Fisheries Oceanography
Open to the public.
All MNE / EAS students are encouraged to attend.
For more information, please contact Dr. Mehdi Raessi:
(mraessi@umassd.edu, 508-999-8496)
Thank you,
Sue Cunha, Administrative Assistant
scunha@umassd.edu
Topical Areas: Faculty, General Public, Staff and Administrators, Students, University Community, College of Engineering, Mechanical Engineering, Physics, Lectures and Seminars