Iranian Coastal and Marine Structural Engineering AssociationJournal of Coastal and Marine Engineering2645-436X1120180101Classification of Barred and Unbarred Beach Profiles in the Caspian Sea1654590ENSoheil Ataei H.Faculty of Civil Engineering, Shahrood University of Technology, Shahrood, Iran0000-0002-9764-8625Mir Ahmad Lashteh NeshaeiDepartment of Civil Engineering, Faculty of Engineering, University of Guilan, Rasht, IranMehdi AdjamiFaculty of Civil Engineering, Shahrood University of Technology, Shahrood, IranJournal Article20170416Nearshore bars are ubiquitous morphological features along many of the world's beaches. They are the main expression of hydrodynamic and sediment transport gradients, with bars developing as a result of sediment convergence and troughs forming in areas of sediment divergence. Nearshore bars are the most dynamic morphological elements of the surf zone and hence they are a major topic of coastal research. The separation between barred and non-barred profiles is generally related to the direction of cross-shore sediment transport. Offshore sediment transport results in erosion of the beach and the formation of barred profiles, whereas onshore sediment transport causes beach accretion and non-barred profiles. The southern coasts of the Caspian Sea were studied in this research. According to the conducted investigations, the southern coasts of Caspian Sea is considered as the type of coast with possibility of bar formation and under normal conditions, three bars would be formed in most of its coasts.https://www.jcme-journal.com/article_54590_22dbf17acde5e3de77b4e2d735ac8ea0.pdfIranian Coastal and Marine Structural Engineering AssociationJournal of Coastal and Marine Engineering2645-436X1120180101Numerical Simulation of Tidal Wave over Wavy Bed71254593ENMaryam Ziaeddini-DashtkhakiDepartment of Civil Engineering,
Faculty of engineering,
Shahid Bahonar University of Kerman,
Kerman, Iran.Mahnaz Ghaeini-HessaroeyehDepartment of Civil Engineering,
Faculty of engineering,
Shahid Bahonar University of Kerman,
Kerman, Iran.Journal Article20170522The HLLC method is a good approximate Riemann solver that has the ability to resolve shock, contact and rarefaction waves. High-order accuracy is achieved using Total Variation Diminishing version of Weighted Average Flux (TVD-WAF) explicit method. The bed topography and friction source terms are treated in a fully implicit method. The accuracy of the scheme has been verified by the implementation of several computational tests. The results show the appropriate agreement of the present model results with the exact and analytical solutions.https://www.jcme-journal.com/article_54593_cca134657114b9d4e7b2402dc9798f05.pdfIranian Coastal and Marine Structural Engineering AssociationJournal of Coastal and Marine Engineering2645-436X1120180101Developing the Persian Gulf Wave Forecasting System131854594ENMorteza Jedari AttariInst. of Geophysics, Univ. of Tehran, Iran0000-0002-6536-5225S. Abbas HaghshenasInst. of Geophysics, Univ. of Tehran, IranMohsen SoltanpourK. N. Toosi University of Technology, Tehran, IranMohammad Reza AllahyarPort and Maritime Organization, Tehran, IraSarmad GhaderInst. of Geophysics, Univ. of Tehran, IranDaniel YazjiInst. of Geophysics, Univ. of Tehran, IranAzadeh Razavi ArabInst. of Geophysics, Univ. of Tehran, IranZohreh HajisalimiPort and Maritime Organization, Tehran, IranS. Jaafar AhmadiInst. of Geophysics, Univ. of Tehran, IranArash BakhtiariK. N. Toosi University of Technology, IranJournal Article20170524This paper represents the detailed procedure and outcomes of a research work aiming to develop a wave forecasting system for the Persian Gulf. Considering the high importance of the Persian Gulf for the economy of the region and the world, the need for a reliable forecast data has increased recently and therefore we have developed and calibrated the forecasting model based on all the available wave data in the domain which distinguishingly increased the accuracy and reliability of the system. The obtained Global Forecast System data (GFS) is implemented in Weather Research and Forecast Model (WRF) and the reproduced high resolution wind field is implemented in the third generation WAVEWATCH III (WW3) model. Each forecast covers a 120-hour prediction and provide the users with precise information regarding significant and maximum wave height and peak wave period and direction on any point at the entire Persian Gulf. The forecasts are updated every 12 hour and consequently customized reports are delivered to the users.https://www.jcme-journal.com/article_54594_e679ccc532e3d574eb305c4623744ef6.pdfIranian Coastal and Marine Structural Engineering AssociationJournal of Coastal and Marine Engineering2645-436X1120180101Pipeline Route Selection Effects on Seawater Intakes Efficiency (Case Study: Bandar Abbas Sako Desalination Plant)192454595ENSeyede Masoome SadaghiRoad, Housing and Urban Development Research Center. Ministry of Road and Urban DevelopmentAli FakherSchool of Civil Engineering, University of Tehran, Tehran, IranZeinab ToorangPars Geometry Consultants, Tehran, IranAlireza Shafieefar4) Pars Geometry Consultants, Tehran, IranJournal Article20170524In the present paper, Bandar Abbas SAKO desalination plant is considered as a case study and the seawater intake and outfall system is investigated from the viewpoint of route optimization. MIKE21-FM and MIKE3-FM have been used for hydrodynamic and salinity dispersion numerical modeling. Intake water quality, recirculation and environmental consideration were the key factors considered in the route optimization. It has been shown that the selection of the right route for the intake and discharge pipelines has a significant effect on the whole system efficiency.https://www.jcme-journal.com/article_54595_09e3c9015c7d243f15f47d56b4390a5c.pdfIranian Coastal and Marine Structural Engineering AssociationJournal of Coastal and Marine Engineering2645-436X1120180101Numerical Study of the Effect of Current Velocity on Power Production by a Horizontal Axis Marine Current Turbine and Feasibility of Using It in the Strait Of Hormuz253354615ENAmir HonaryarFaculty of Marine Technology, Amirkabir University of Technology, Hafez Avenue, 15875-4413 Tehran, IranMahmoud GhiasiFaculty of Marine Technology, Amirkabir University of Technology, Hafez Avenue, 15875-4413 Tehran, IranJournal Article20170522The effect of current velocity on power production by a Horizontal Axis Marine Current Turbine (HAMCT) has been investigated. In this paper, a two-step procedure was used for numerical analysis of the turbine. In the first step, Blade Element Momentum Theory (BEMT) was used to reach an initial configuration for the blades of turbine. Chord and twist distributions along the blade length, and hydrodynamic torque produced by HAMCT were estimated using this theory. Then in the second step, a numerical method based on Computational Fluid Dynamics (CFD) was used to achieve a better understanding of the turbine performance and fluid flow characteristics around the blades. Finally, feasibility of using the HAMCT in the Strait of Hormuz was studied. The CFD simulations provided the flow field within the computational domain. Spatial integration of the pressure distribution around the blades yields hydrodynamic torque generated by the HAMCT. The results have also provided the variation of rotor torque with the tidal current velocity. Findings showed that increase in the tidal current velocity to a little more than 2 m/s, increases the torque as the square of the velocity. However, increasing the velocity beyond 2 m/s doesn’t change the torque. In other words, torque remains almost constant because the rotor speed is constant and equal to 11.5 rpm. Finally, it was concluded that by installing a marine power plant which consists of an array of 10 HMCT systems in the Qeshm channel, 10 MW power can be generated.https://www.jcme-journal.com/article_54615_5242eb75780a80e57741f9f2bdb1f882.pdfIranian Coastal and Marine Structural Engineering AssociationJournal of Coastal and Marine Engineering2645-436X1120180101Stress Concentration Factors Of FRP-Wrapped Tubular T-Joints Of Jacket Type Offshore Platforms under Brace Axial Loading343854616ENAlireza Sadat HosseiniDepartment of Civil Engineering, College of Engineering, University of Tehran, Tehran, IranMohamad Reza BahaariDepartment of Civil Engineering, College of Engineering, University of Tehran, Tehran, IranMohamad LesaniDepartment of Civil Engineering, College of Engineering, Sadra University, Tehran, IranJournal Article20170522<span>The present research investigates the relative stress concentration factors (SCF) in a T-joint strengthened with fiber reinforced polymers (FRP) subjected to brace axial loading employing finite element analysis. In this research, three types of FRP material consisting of glass-vinyl ester, glass-epoxy and carbon-epoxy were used as strengthening materials. The FRP was applied on a basic numerical FE model, which were validated against the well-known experimental results on weld toe SCFs. The results showed that the use of stiffer FRP materials on the chord induced more reduction in SCF values. Besides, the use of carbon-epoxy material had efficacy about three times that of GFRP materials in decreasing SCF values. Carbon-epoxy with thickness of 1mm, as the strengthening material decreased the SCF values up to 2.5 and 10.1% at the chord crown and saddle points, respectively.</span>https://www.jcme-journal.com/article_54616_1aa58e7aa7b92c8305a5b2bea3b33286.pdfIranian Coastal and Marine Structural Engineering AssociationJournal of Coastal and Marine Engineering2645-436X1120180101SPH Modeling of Heave Motion Response of Pile-Supported Floating Breakwater394554617ENKaveh SoleimaniMohammadjavad KetabdariAmirkabir University of TechnologyJournal Article20170524The interaction of sea waves and floating bodies is one of the pioneering fields of study in marine technology that has recently received a lot of attention. Floating breakwater can be an alternative for conventional breakwaters in anomalous conditions such as deep water, insufficient seabed and high sedimentation rates in typical wave climates where there is no need for full protection.In this article, the heave motion response of a single degree of freedom pile-supported floating breakwater was investigated employing WCSPH technique. To describe the momentum equation, the laminar viscous stress model, and to surmount the spurious pressure oscillation of the numerical technique, the Shepard density filter was employed. In addition, three different weighting functions including Gaussian, Cubic Spline and Quintic (Wendland) were compared to select the most appropriate one for modeling. The results showed that the Cubic Spline and Quintic weighting functions were more appropriate in navigating a solution for the problems with this kind of wave structure interaction. The velocity field near the FB showed that the maximum velocity of water particles occurred near the sharp edges of the body.https://www.jcme-journal.com/article_54617_dc3aab4ebc409c93175e4602cb4b3535.pdfIranian Coastal and Marine Structural Engineering AssociationJournal of Coastal and Marine Engineering2645-436X1120180101Numerical Analysis of the Effects of Sandglass-Type FPSO Hull Form on Hydrodynamic Performance in Regular Waves465254618ENAdeleh GrayleeNoshirvani University of Technology, Babol, IranMahdi YousefifardNoshirvani University of Technology, Babol, IranJournal Article20170529<span>This paper presents a numerical investigation on hydrodynamic performance of sandglass-type FPSO with different parameters. In order to estimate the hydrodynamic performance and utilize the results on the design stage of FPSO, a frequency-domain numerical simulation program, ANSYS/AQWA software package was used. Numerical studies were conducted to investigate the heave and pitch motion responses of sandglass-type FPSO. Eight different inclination angles were utilized with the same displacement and draft. The effects of different inclination angles including different radii of underwater radius of floating object on hydrodynamic responses and forces that acted on FPSO were investigated and presented here. Numerical results were compared against experimental data of a sandglass-type model, and good agreement was achieved in small amplitude regular wave cases. Based on the simulation results, it was concluded that a sandglass-type FPSO with inclination angle of 45º proposes proper hydrodynamic performance in heave and pitch motion for all ranges of wave frequencies. Also as it was predicted, the effect of heading sea on sandglass-type FPSO was significant compared to other wave directions.</span>https://www.jcme-journal.com/article_54618_7b9e30c7266c07785ed58109cecdd2bf.pdfIranian Coastal and Marine Structural Engineering AssociationJournal of Coastal and Marine Engineering2645-436X1120180101Numerical Analysis of Upheaval Buckling of Pipeline on Uneven Seabed Using Finite Element Method535758560ENAli Soukhak LariMaritime Engineering Department, MSc in Marine Structures Engineering, Amirkabir University of Technology, Tehran, Iran0000-0002-1499-3651Ahmad Rahbar RanjiMaritime Engineering Department, Associate Professor, Amirkabir University of Technology, Tehran, IranMostafa Bahmani ShourijehCivil Engineering Department, Shiraz University, Shiraz, IranMehdi Soukhak LariMaritime Engineering Department, MSc in Coasts & Ports Engineering, Amirkabir University of Technology, Tehran, IranJournal Article20170523<span>When subsea pipelines are laid down on the uneven seabed or buried in the seafloor, they may experience upheaval buckling. This condition, which is associated with high temperature and high pressure (HT/HP) of oil in the pipeline leads to large displacement. Finally, bending moment and effective axial force are produced. This way, the cross section of the pipeline may experience failure. In this research, a pipeline on the seabed is simulated employing ABAQUS software, and various influential factors such as the friction coefficient of seabed soil, external and internal hydrostatic pressure and temperature changes in the process of creating upheaval buckling are assessed. The results show that the friction coefficient of soil have much more effect than the other parameters. Furthermore, the pipeline would be unstable when the efficacious axial force increases. </span>https://www.jcme-journal.com/article_58560_4822b39c5039e012bedcd3b5168a3cfc.pdfIranian Coastal and Marine Structural Engineering AssociationJournal of Coastal and Marine Engineering2645-436X1120180101Modeling of Last Recent Tropical Storms in the Arabian Sea586660709ENArash BakhtiariMohammad Reza AllahyarIranian Ports and Maritime OrganizationMorteza Jedari Attarivisiting lecturer, Institute of Geophysics, University of Tehran0000-0002-6536-5225S. Abbas HaghshenasInst. of Geophysics, Univ. of Tehran, IranMohammad BagheriIranian Ports and Maritime OrganizationJournal Article20170524The Gulf of Oman and the Makran coastline as a part of the Arabian Sea are subjected to tropical cyclones influence on an infrequent basis; however, these cyclones can generate relatively large sea states. In this paper, recent tropical cyclones in the Arabian Sea were studied employing a third-generation spectral wave model and a 2D hydrodynamic model. The wind field of all cyclones is produced through an empirical wind generation model. The results of wave and hydrodynamic models are compared with data measured at different stations on the Gulf of Oman. The significant wave height, the peak wave period, the mean wave direction, and the water level changes are the four key features taken into consideration.
Based on the results, it could be concluded that the Young and Sobey parametric model is an appropriate technique to regenerate cyclonic wind fields over the Arabian Sea. In addition, the significant wave height, peak wave period, and the mean wave direction were reasonably predicted, despite the fact that the water level changes of the model were to some extent underestimated. The distribution of the wave fields and water level changes are presented to investigate the critical wave and surge in the study area.https://www.jcme-journal.com/article_60709_9a828b062e2b2d7314cc2110b804e9bd.pdf