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Optimization of Bottom-hinged Flap-type Wave Energy Converter for a Specific Wave Rose

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Journal of Marine Science and Application 2017年第2期16卷 159-165页

作者： Hamed Behzad roozbeh panahi Department of Civil Engineering Tarbiat Modares University Tehran 14115-116 Iran

In this paper, we conducted a numerical analysis on the bottom-hinged flap-type Wave Energy Convertor (WEC). The basic model, implemented through the study using ANSYS-AQWA, has been validated by a three-dimensional physical model of a pitching vertical cylinder. Then, a systematic parametric assessment has been performed on stiffness, damping, and WEC direction against an incoming wave rose, resulting in an optimized flap-type WEC for a specific spot in the Persian Gulf. Here, stiffness is tuned to have a near-resonance condition considering the wave rose, while damping is modified to capture the highest energy for each device direction. Moreover, such sets of specifications have been checked at different directions to present the best combination of stiffness, damping, and device heading. It has been shown that for a real condition, including different wave heights, periods, and directions, it is very important to implement the methodology introduced here to guarantee device performance.

关键词： wave energy converter bottom-hinged flap power take-off system directional analysis optimization wave rose

Parametric Study of Two-Body Floating-Point Wave Absorber

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Journal of Marine Science and Application 2016年第1期15卷 41-49页

作者： Atena Amiri roozbeh panahi Soheil Radfar Faculty of Civil and Environmental Engineering Tarbiat Modares University Tehran 14115-143 Iran

In this paper, we present a comprehensive numerical simulation of a point wave absorber in deep water. Analyses are performed in both the frequency and time domains. The converter is a two-body floating-point absorber （FPA） with one degree of freedom in the heave direction. Its two parts are connected by a linear mass-spring-damper system. The commercial ANSYS-AQWA software used in this study performs well in considering validations. The velocity potential is obtained by assuming incompressible and irrotational flow. As such, we investigated the effects of wave characteristics on energy conversion and device efficiency, including wave height and wave period, as well as the device diameter, draft, geometry, and damping coefficient. To validate the model, we compared our numerical results with those from similar experiments. Our study results can clearly help to maximize the converter＇s efficiency when considering specific conditions.

关键词： floating-point absorber wave energy energy absorption Wave Energy Converter (WEC) Power Take Off (PTO) numerical simulation

Standardization of the Main Dimensions of Design Container Ships in Ports—A Case Study

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World Journal of Engineering and Technology 2017年第4期5卷 51-61页

作者： Soheil Radfar Amir Taherkhani roozbeh panahi Department of Marine Structures Tarbiat Modares University Tehran Iran

Ports are crucial element in the export and import chains of each country. Therefore, sufficient and efficient designing of ports is of great importance to increase the safety of operations and to lower the construction costs. Their design procedure is iterative and specifications of the design ship are of the most important inputs in this regard. The design ship is characterized with its length (L), breadth (B), and draft (d). In this research a regression analysis has been carried out in the southern coasts of Iran (Persian Gulf) to obtain these specifications. The results have shown under- and over-estimations of the main dimensions. Hence, this supports the idea that it is worth performing individual regression analysis, especially in restricted waterways and in the regions with specific fleet for the sake of verification of recommended values by standard technical guidelines.

关键词： Length Breadth Draft Dead Weight Tonnage Terminal

An Appropriate Unidirectional Wave Spectrum Model for the Strait of Hormuz

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Journal of Marine Science and Application 2015年第3期14卷 261-269页

作者： Reza Ghazangian Mehdi Shafieefar roozbeh panahi Mohammad R. Allahyar Faculty of Civil and Environmental Engineering Tarbiat Modares University Tehran 14115-143 Iran Port and Maritime Organization Tehran 6316-15875 Iran

The objective of this paper is to introduce an appropriate unidirectional wave spectrum model for the Strait of Hormuz. The research is focused on assessing performance of standard wave spectrum models in the region. By evaluating such models based on valuable measurement data recently published, the calibration procedure has been conducted on such standard models to reach a better concordance between a modified standard spectral model and observed field spectra. The calibration is performed initially with respect to four distinct directions related to four available measurement stations. So, it results in four sets of coefficients for a nominated model. Next, it is continued to reach just one model insensitive to directions. Results clearly showed that the International Towing Tank Conference （ITTC） model is more appropriate than Joint North Sea Wave Project （JONSWAP） and Pierson and Moskowitz （PM） models in this area, even without any calibration. However, modifications have been successful on improving the conformity of the model.

关键词： calibration JONSWAP model International Towing Tank Conference (ITTC) model Pierson and Moskowitz (PM) model Strait of Hormuz water wave spectrum

A finite volume algorithm based on overlapping meshes for simulation of hydrodynamic problems

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Journal of Marine Science and Application 2009年第4期8卷 281-290页

作者： roozbeh panahi Mehdi SHFIEEFAR Civil Engineering Department Tarbiat Modares University

A finite volume algorithm was established in order to investigate two-dimensional hydrodynamic problems. These include viscous free surface flow interaction with free rigid bodies in the case of large and/or relative motions. Two-phase flow with complex deformations at the interface was simulated using a fractional step-volume of fluid algorithm. In addition, body motions were captured by an overlapping mesh system. Here, flow variables are transferred using a simple fully implicit non-conservative interpolation scheme which maintains the second-order accuracy of implemented spatial discretisation. Code was developed and an appropriate set of problems investigated. Results show good potential for development of a virtual hydrodynamics laboratory.

关键词： interfacial flow fluid-structure interaciion wave tank