Journal Articles
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/19884
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Item Wave Interaction With Floating Elastic Plate Based on the Timoshenko-Mindlin Plate Theory(American Society of Mechanical Engineers (ASME) infocentral@asme.org, 2019) Praveen, K.M.; Karmakar, D.; Guedes Soares, C.In the present study, the wave interaction with the very large floating structures (VLFSs) is analyzed considering the small amplitude wave theory. The VLFS is modeled as a 2D floating elastic plate with infinite width based on Timoshenko-Mindlin plate theory. The eigenfunction expansion method along with mode-coupling relation is used to analyze the hydroelastic behavior of VLFSs in finite water depth. The contour plots for the plate covered dispersion relation are presented to illustrate the complexity in the roots of the dispersion relation. The wave scattering behavior in the form of reflection and transmission coefficients are studied in detail. The hydroelastic performance of the elastic plate interacting with the ocean wave is analyzed for deflection, strain, bending moment, and shear force along the elastic plate. Further, the study is extended for shallow water approximation, and the results are compared for both Timoshenko-Mindlin plate theory and Kirchhoff's plate theory. The significance and importance of rotary inertia and shear deformation in analyzing the hydroelastic characteristics of VLFSs are presented. The study will be helpful for scientists and engineers in the design and analysis of the VLFSs. © 2019 by ASME.Item Wave transformation due to finite floating elastic plate with abrupt change in bottom topography(Taylor and Francis Ltd., 2022) Praveen, K.M.; Venkateswarlu, V.; Karmakar, D.The propagation of surface gravity waves in the presence of finite floating elastic plate over varying sea bottom profile is investigated using the Timoshenko-Mindlin plate theory. The continuity of velocity and pressure at the interfaces along with the continuity of deflection, slope, bending moment and shear force is employed with the support conditions at the plate edges. The numerical computation is performed to obtain the hydroelastic behaviour of the floating elastic plate due to abrupt change in bottom topography. The validation of the present analytical model is performed with the known results available in the literatures. Further, a detailed comparison of the numerical results is presented for different step bottom topography on the hydroelastic characteristics of a floating elastic platform. The present study will provide an insight into the effect of the ocean bottom profile on wave propagation due to the presence of a large floating elastic plate. © 2021 Informa UK Limited, trading as Taylor & Francis Group.Item Numerical investigation of offshore wind turbine combined with wave energy converter(Springer Nature, 2023) Rony, J.S.; Sai, K.C.; Karmakar, D.The coupled dynamic analysis is performed for three different types of offshore floating platforms combined with a wave energy converter (WEC) mounting a 5-MW NREL (National Renewable Energy Laboratory) wind turbine. The Response Amplitude Operators (RAOs) are analysed for the three concepts of combined wind and wave energy platforms for different wind and wave conditions. The hydrodynamic performance for the three different platforms is conducted considering different load cases. The time domain aero-servo-hydro-elastic tool is used to study the motion responses of the combined system under real operational conditions. The platform’s responses are observed to increase with the increase in the wind speed. In the case of floating hybrid platform, surge responses are minimal for the hybrid spar-tours combination for any load case condition. Minimum surge and sway ensure higher wind power absorption. The study further focuses on the tower base forces and moments to study the impact of wind and waves on the combined floater. Fore-aft shear forces and fore-aft bending moments are higher for the platforms indicating the importance of wind-wave loading. The time domain responses are further used as the transfer function to predict the most probable maximum values of motion amplitude expected to occur during the life-time of the structure which can be used for designing a floating wind turbine (FWT) against overturning in high waves. The long-term models are constructed using various short-term situations expected to occur during the structure’s life-time and weighing them appropriately. The long-term distribution uses North Atlantic wave data, and short-term responses are calculated considering Rayleigh distribution. A brief comparative study of the three combined offshore floaters is performed to understand the structural integrity, power performance and dynamic motions of the floating wind energy platform combined with WECs. © 2023, The Author(s), under exclusive licence to Sociedade Brasileira de Engenharia Naval.Item Hydrodynamic performance of an oscillating water column WEC integrated with a pile-restrained H-type breakwater(Taylor and Francis Ltd., 2025) Vishwakarma, R.D.; Muduli, R.; Karmakar, D.The present study examines the hydrodynamic performance of an oscillating water column (OWC) wave energy converter (WEC) integrated into a pile restrained H-type breakwater. A three-dimensional model study is performed using ANSYS-AQWA based on potential flow theory. The results for the incident wave excitation force, shear force, and bending moment on the pile restrained breakwater and the transmission coefficient are obtained for the regular waves. The effect of incident wave angle on the forces is assessed along with the impact of changes in relative draft and width of the device. The power capture efficiency as well as wave transformation characteristics of the device are evaluated using Boundary Element Method (BEM). The study performed will be helpful to scientists and researchers to design and develop an integrated hybrid breakwater system that can protect the coast and provide useful energy by minimising the impact on the marine ecological system and environment. © 2025 Informa UK Limited, trading as Taylor & Francis Group.