فصلنامه علوم و فناوری دریا
سال بیست و ششم شماره 101 (بهار 1401)

Vibration of the structures in contact with fluid is a phenomenon that a structure has the interaction between the fluid. Hydroelastic characteristics of plates in contact with fluid are important in various engineering applications such as in nuclear engineering, liquid storage tanks, reactor internal components, and solar plates and offshore, naval or marine structures. Fluid-coupled vibrations may be caused the structural fatigue and failure. So, the control and debilitation of the hydoelastic characteristics are important in the safety positions. This study is focused on the hydroelastic vibration of FG circular plate in contact with the bounded fluid with clamped boundary conditions. The natural frequencies of the plate coupled with fluid are calculated by finite element software ANSYS. The software method is verified by comparing the results with the results obtained by experimental tests in case homogeneous plate (Aluminum). Finally, the effects of some parameters such as fluid density, fluid height and volume fraction index on natural frequencies are discussed in details.

Today, due to the development of renewable energy sources, the global energy crisis, issues related to environmental pollution and international restrictions, the use of solar energy along with energy storage systems on ships has attracted much attention. has done. However, in the electrical system of ships, there is a lot of sensitive equipment that can be very sensitive to voltage disturbances, and if the disturbances of the voltage are greater than the weight of the tank, it is too heavy. Voltage disturbances are mainly caused by a decrease in voltage, an increase in voltage, a decrease in voltage, a decrease in the voltage on the floor and a half. امی Dynamic voltage measurement DVR is one of the most effective and common tools that can be used to reduce voltage disturbances. In this paper, a hybrid system consisting of a synchronous generator and a solar cell with the presence of dynamic voltage recovery is presented for use in the ship. The simulation results obtained by Matlab / Simulink software also show the presence of dynamic voltage recovery. Reduce disturbances

Under the sanctions of the oil and petrochemical industries, rotating equipment, including gas turbines, has always been in the center of attention of activists and experts in the relevant fields due to its high level of knowledge of design and manufacturing technology. In engineering processes, time and accuracy are two issues that can not be ignored. Recent studies using three-dimensional finite element analysis have predicted the rate of failure and deformation relatively accurately, but modeling uncertainty is an important and negligible issue because it affects the probability of sample failure. Give. In this study, for a deep understanding of the behavior of gas turbine blades under aerodynamic and thermal loads, four types of materials in the input properties have been used. Stress and deformation analysis is designed so that the effects of energy, material properties, geometry and thermal boundaries are applied separately to all areas of the part. Given the research importance mentioned above, this work is not only significant for deepening the understanding of turbine blade behavior, but also for providing industry guidance for optimizing the design and fabrication processes of this component. The results showed that the highest stress created in the application of absolute heat load and in the sample of incremental construction and nickel base alloy and the highest deformation occurred for 7075 aluminum. Also, the results of blades made with nickel and incremental construction are similar, but due to lower cost and less machining, the blade made with incremental construction is more economical.

Purpose of this research is development and optimizing of supported lands, trough identification of strengths, weaknesses, opportunities and threats in these lands.This research has done in two phases; first phase is identification of factors affecting supported lands and general condition of BIK port using foretime researches.In second phase, factors prepared in a questionnaire and distributed between statistic samples.126 numbers of questionnaire were answered. Descriptive statics shown that repliers were covering bulk and container experts , port and maritime affairs experts, research advisors, manager of port and maritime operation and active merchants in BIK port.In this research T test is used for specifying condition of 24 effective factors on supported lands and SWOT matrix is used for classification of these factors. Most important results of T test are as follow:Fundamental substructure such as electrical power, fresh water, and firm’s independency (strengths) .lack of modern load/discharging machinery and logistic soft wares (weakness). Willing of CIS countries for transiting cargo from BIK port and feasibility of supported lands development (opportunity).development of 2700 hectare of Bandar Shahid Rajaee and complicated administrative paper works (threat).Adequate strategies were proposed for each possible case, such as physical and substructure development strategy. Development and improvement of access roads to the hinter lands, reinforcement of publicity and marketing on capability of hinterlands and decision on use of present transportation capacities.

The aim of research is Evaluation effective factors on performance of HSE in Pars Service Port. The research has application nature and in methodology is a survey-descriptive method. With using of national and international researches, 20 factors impact on performance of HSE in Pars Service Port identified and designed in questionnaire and replied by 83 of responsible and experts of HSE of companies in Pars Service Port. Findings of the research show human resources of this department (number and their education), equipment, superior managers and employees of port, workers and employers active in port and regulating are macro factors impact on performance of HSE department. Among identified factors, superior managers and employees of port, employers active in port and regulating have good condition but workers haven’t good performance in environment subject. Also human resources of this department (number and their education) and equipment have problems and need to consider them.

In this research, by using Experimental and numerical methods, the hydrodynamic parameters of high-speed prismatic vessel including resistance, rise up and trim for two deadrise angles of 20 and 25 have been investigated. In this paper, first, the experimental results with 2 deadrise angles 20 and 25 with David Taylor Towing Tank results are compared and the hydrodynamic parameters including resistance, rise up and trim are investigated. Then, by modeling the vessel by finite volume method and computational fluid dynamics, the hydrodynamic parameters have been validated and compared and the wet surface of the vessel has been computed at two deadrise angles in different forward speeds. In this study, it was found that the amount of floating resistance increases with increasing deadrise angle. Also, the dynamic trim decreases with increasing deadrise angles at different forward speeds.