The Experts below are selected from a list of 276 Experts worldwide ranked by ideXlab platform

Barbaros Celikkol - One of the best experts on this subject based on the ideXlab platform.

  • The Heave Response of a Central Spar Fish Cage
    Journal of Offshore Mechanics and Arctic Engineering, 2003
    Co-Authors: David W. Fredriksson, M. Robinson Swift, James D. Irish, Barbaros Celikkol
    Abstract:

    As the aquaculture industry considers moving into the open ocean, understanding the dynamic Response of fish containment structures becomes critical. Identification of possible resonant conditions and motion characteristics is necessary for system structural integrity and maximizing fish survivability. In this study, Heave (vertical motion) free release tests of a central spar fish cage were conducted using a combination of physical and finite-element (FE) models and field observations. These tests were performed to investigate the added mass, damping and natural period characteristics of the system in the vertical direction. The test results were analyzed considering both linear and nonlinear damping. The comparison of these tests show that: the damped natural period of this fish cage is longer than 20 seconds; the numerical model underestimates the damping and the cage oscillates longer and at a higher frequency than observed with the field tests; and the physical model is nearly critically damped near equilibrium due to Reynolds number effects at the model scale.

  • The Heave Response of a Central Spar Fish Cage
    21st International Conference on Offshore Mechanics and Arctic Engineering Volume 4, 2002
    Co-Authors: David W. Fredriksson, M. Robinson Swift, James D. Irish, Barbaros Celikkol
    Abstract:

    As the aquaculture industry considers moving into the open ocean, understanding the dynamic Response of fish containment structures becomes critical. Identification of possible resonant conditions and motion characteristics is necessary for system structural integrity and maximizing fish survivability. In this study, Heave (vertical motion) free release tests of a central spar fish cage were conducted using a combination of physical and finite element models and field observations. These tests were performed to investigate the added mass, damping ratio and natural period of the system in the vertical direction. The test results were analyzed considering both linear and nonlinear damping. The comparison of these tests show that (1) the damped natural period of this fish cage is longer than 20 seconds, (2) the numerical model underestimates the damping and the cage oscillates longer and at a higher frequency than observed with the field tests and (3) the physical model is nearly critically damped near equilibrium due to Reynolds number effects at the model scale.Copyright © 2002 by ASME

Arunachalam Amarkarthik - One of the best experts on this subject based on the ideXlab platform.

  • Investigation on modeling of non-buoyant body typed point absorbing wave energy converter using Adaptive Network-based Fuzzy Inference System
    International Journal of Marine Energy, 2016
    Co-Authors: Arunachalam Amarkarthik, Karuppan Sivakumar
    Abstract:

    Abstract This study investigates the applicability of Adaptive Neuro-Fuzzy Inference System (ANFIS) technique to predict the performance of a non-buoyant body typed wave energy converter. The non-buoyant body typed wave energy converter is a novel device which uses a water filled container as front end interface instead of a traditional buoyant buoy. A lab scale experimental investigation on the energy conversion efficiency of the device and its Heave Response were carried out on a small scale model and found that the results were competitive when compared with a buoy typed wave energy converter. Soon after the experimental validations, mathematical model of the device was developed and tested for predicting the device behavior during various wave conditions. To test the viability of a soft computing tool to predict the behavior of a non-buoyant body typed wave energy converter, Adaptive Network-based Fuzzy Interface System was selected due to its predictive ability in uncertain environment. Further, four ANFIS models were developed, trained and validated with the recorded data and applied to predicting the Heave Response in various wave conditions. The validation results confirm the applicability of the developed ANFIS models for predicting the device behavior over a wide range of wave parameters. The study demonstrates that the ANFIS model is capable of predicting the device behavior with a high degree of accuracy at minimum time. Once modeled, the ANFIS model can be used on behalf of the experimental setup to carryout further experiments to perform the optimization process.

  • Science of Efficiency Improvement of Point Absorber using a Non-Floating object for Ocean Wave Energy Conversion
    Asian Journal of Research in Social Sciences and Humanities, 2016
    Co-Authors: Arunachalam Amarkarthik, Srinivasan Chandrasekaran, K. Sivakumar
    Abstract:

    A novel method of improving hydrodynamic efficiency by using a cylindrical non-buoyant body instead of floating body in point absorber type wave energy conversion is studied. The proposed novel method has the potential to significantly improve the energy conversion rate and reliability when compared to other recently proposed devices. To illustrate the improved performance and reliability of the proposed device, a simple two degree of freedom system was constructed and experimented at a wave tank. Heave Response of the non-buoyant body was measured by placing an accelerometer for various wave and device parameters. The instantaneous excited force on non-buoyant body was obtained by calculating net angular momentum from measured instantaneous Heave acceleration and system mass. The resulting force conversion shows that the force excited on the body is significantly higher than the force excited by the wave. It was proved from the experiment that this improved force conversion is the result of novel working principle of the device. It is also objective to show that the device use no complicated mechanisms like latching control, damping control, change of float forms or moving parts like flaps to improve the Heave Response.

  • Experimental investigation and ANN modeling on improved performance of an innovative method of using Heave Response of a non-floating object for ocean wave energy conversion
    Frontiers in Energy, 2013
    Co-Authors: Srinivasan Chandrasekaran, Arunachalam Amarkarthik, Karuppan Sivakumar, Dhanasekaran Selvamuthukumaran, Shaji Sidney
    Abstract:

    To convert wave energy into usable forms of energy by utilizing heaving body, heaving bodies (buoys) which are buoyant in nature and float on the water surface are usually used. The wave exerts excess buoyancy force on the buoy, lifting it during the approach of wave crest while the gravity pulls it down during the wave trough. A hydraulic, direct or mechanical power takeoff is used to convert this up and down motion of the buoy to produce usable forms of energy. Though using a floating buoy for harnessing wave energy is conventional, this device faces many challenges in improving the overall conversion efficiency and survivability in extreme conditions. Up to the present, no studies have been done to harness ocean waves using a non-floating object and to find out the merits and demerits of the system. In the present paper, an innovative heaving body type of wave energy converter with a non-floating object was proposed to harness waves. It was also shown that the conversion efficiency and safety of the proposed device were significantly higher than any other device proposed with floating buoy. To demonstrate the improvements, experiments were conducted with non-floating body for different dimensions and the Heave Response was noted. Power generation was not considered in the experiment to observe the worst case Response of the heaving body. The device was modeled in artificial neural network (ANN), the Heave Response for various parameters were predicted, and compared with the experimental results. It was found that the ANN model could predict the Heave Response with an accuracy of 99%.

David W. Fredriksson - One of the best experts on this subject based on the ideXlab platform.

  • The Heave Response of a Central Spar Fish Cage
    Journal of Offshore Mechanics and Arctic Engineering, 2003
    Co-Authors: David W. Fredriksson, M. Robinson Swift, James D. Irish, Barbaros Celikkol
    Abstract:

    As the aquaculture industry considers moving into the open ocean, understanding the dynamic Response of fish containment structures becomes critical. Identification of possible resonant conditions and motion characteristics is necessary for system structural integrity and maximizing fish survivability. In this study, Heave (vertical motion) free release tests of a central spar fish cage were conducted using a combination of physical and finite-element (FE) models and field observations. These tests were performed to investigate the added mass, damping and natural period characteristics of the system in the vertical direction. The test results were analyzed considering both linear and nonlinear damping. The comparison of these tests show that: the damped natural period of this fish cage is longer than 20 seconds; the numerical model underestimates the damping and the cage oscillates longer and at a higher frequency than observed with the field tests; and the physical model is nearly critically damped near equilibrium due to Reynolds number effects at the model scale.

  • The Heave Response of a Central Spar Fish Cage
    21st International Conference on Offshore Mechanics and Arctic Engineering Volume 4, 2002
    Co-Authors: David W. Fredriksson, M. Robinson Swift, James D. Irish, Barbaros Celikkol
    Abstract:

    As the aquaculture industry considers moving into the open ocean, understanding the dynamic Response of fish containment structures becomes critical. Identification of possible resonant conditions and motion characteristics is necessary for system structural integrity and maximizing fish survivability. In this study, Heave (vertical motion) free release tests of a central spar fish cage were conducted using a combination of physical and finite element models and field observations. These tests were performed to investigate the added mass, damping ratio and natural period of the system in the vertical direction. The test results were analyzed considering both linear and nonlinear damping. The comparison of these tests show that (1) the damped natural period of this fish cage is longer than 20 seconds, (2) the numerical model underestimates the damping and the cage oscillates longer and at a higher frequency than observed with the field tests and (3) the physical model is nearly critically damped near equilibrium due to Reynolds number effects at the model scale.Copyright © 2002 by ASME

Karuppan Sivakumar - One of the best experts on this subject based on the ideXlab platform.

  • Investigation on modeling of non-buoyant body typed point absorbing wave energy converter using Adaptive Network-based Fuzzy Inference System
    International Journal of Marine Energy, 2016
    Co-Authors: Arunachalam Amarkarthik, Karuppan Sivakumar
    Abstract:

    Abstract This study investigates the applicability of Adaptive Neuro-Fuzzy Inference System (ANFIS) technique to predict the performance of a non-buoyant body typed wave energy converter. The non-buoyant body typed wave energy converter is a novel device which uses a water filled container as front end interface instead of a traditional buoyant buoy. A lab scale experimental investigation on the energy conversion efficiency of the device and its Heave Response were carried out on a small scale model and found that the results were competitive when compared with a buoy typed wave energy converter. Soon after the experimental validations, mathematical model of the device was developed and tested for predicting the device behavior during various wave conditions. To test the viability of a soft computing tool to predict the behavior of a non-buoyant body typed wave energy converter, Adaptive Network-based Fuzzy Interface System was selected due to its predictive ability in uncertain environment. Further, four ANFIS models were developed, trained and validated with the recorded data and applied to predicting the Heave Response in various wave conditions. The validation results confirm the applicability of the developed ANFIS models for predicting the device behavior over a wide range of wave parameters. The study demonstrates that the ANFIS model is capable of predicting the device behavior with a high degree of accuracy at minimum time. Once modeled, the ANFIS model can be used on behalf of the experimental setup to carryout further experiments to perform the optimization process.

  • Experimental investigation and ANN modeling on improved performance of an innovative method of using Heave Response of a non-floating object for ocean wave energy conversion
    Frontiers in Energy, 2013
    Co-Authors: Srinivasan Chandrasekaran, Arunachalam Amarkarthik, Karuppan Sivakumar, Dhanasekaran Selvamuthukumaran, Shaji Sidney
    Abstract:

    To convert wave energy into usable forms of energy by utilizing heaving body, heaving bodies (buoys) which are buoyant in nature and float on the water surface are usually used. The wave exerts excess buoyancy force on the buoy, lifting it during the approach of wave crest while the gravity pulls it down during the wave trough. A hydraulic, direct or mechanical power takeoff is used to convert this up and down motion of the buoy to produce usable forms of energy. Though using a floating buoy for harnessing wave energy is conventional, this device faces many challenges in improving the overall conversion efficiency and survivability in extreme conditions. Up to the present, no studies have been done to harness ocean waves using a non-floating object and to find out the merits and demerits of the system. In the present paper, an innovative heaving body type of wave energy converter with a non-floating object was proposed to harness waves. It was also shown that the conversion efficiency and safety of the proposed device were significantly higher than any other device proposed with floating buoy. To demonstrate the improvements, experiments were conducted with non-floating body for different dimensions and the Heave Response was noted. Power generation was not considered in the experiment to observe the worst case Response of the heaving body. The device was modeled in artificial neural network (ANN), the Heave Response for various parameters were predicted, and compared with the experimental results. It was found that the ANN model could predict the Heave Response with an accuracy of 99%.

James D. Irish - One of the best experts on this subject based on the ideXlab platform.

  • The Heave Response of a Central Spar Fish Cage
    Journal of Offshore Mechanics and Arctic Engineering, 2003
    Co-Authors: David W. Fredriksson, M. Robinson Swift, James D. Irish, Barbaros Celikkol
    Abstract:

    As the aquaculture industry considers moving into the open ocean, understanding the dynamic Response of fish containment structures becomes critical. Identification of possible resonant conditions and motion characteristics is necessary for system structural integrity and maximizing fish survivability. In this study, Heave (vertical motion) free release tests of a central spar fish cage were conducted using a combination of physical and finite-element (FE) models and field observations. These tests were performed to investigate the added mass, damping and natural period characteristics of the system in the vertical direction. The test results were analyzed considering both linear and nonlinear damping. The comparison of these tests show that: the damped natural period of this fish cage is longer than 20 seconds; the numerical model underestimates the damping and the cage oscillates longer and at a higher frequency than observed with the field tests; and the physical model is nearly critically damped near equilibrium due to Reynolds number effects at the model scale.

  • The Heave Response of a Central Spar Fish Cage
    21st International Conference on Offshore Mechanics and Arctic Engineering Volume 4, 2002
    Co-Authors: David W. Fredriksson, M. Robinson Swift, James D. Irish, Barbaros Celikkol
    Abstract:

    As the aquaculture industry considers moving into the open ocean, understanding the dynamic Response of fish containment structures becomes critical. Identification of possible resonant conditions and motion characteristics is necessary for system structural integrity and maximizing fish survivability. In this study, Heave (vertical motion) free release tests of a central spar fish cage were conducted using a combination of physical and finite element models and field observations. These tests were performed to investigate the added mass, damping ratio and natural period of the system in the vertical direction. The test results were analyzed considering both linear and nonlinear damping. The comparison of these tests show that (1) the damped natural period of this fish cage is longer than 20 seconds, (2) the numerical model underestimates the damping and the cage oscillates longer and at a higher frequency than observed with the field tests and (3) the physical model is nearly critically damped near equilibrium due to Reynolds number effects at the model scale.Copyright © 2002 by ASME