eng Iranian Association of Naval Architecture & Marine Engineering International Journal of Maritime Technology 2345-6000 2476-5333 2024-05 20 1 12 article Majid Nikkhah m.nikkhah@shahroodut.ac.ir 1 Faculty of Mining, Petroleum & Geophysics Engineering, Shahrood University of Tecnology The design and construction of the harbour structure takes a lot of time and cost to be put into operation, and its regular safety, surveillance and evaluation is no less important than the design and construction stages. The importance of this matter is revealed from the fact that in case of any defects and problems, it will lead to damage to this structure or in a critical condition, it will cause failure and the impossibility usage it. In addition to the loss of huge capital, it may also cause irreparable injuries. In this paper, while introducing the instrumentation of the structural health monitoring system, the investigation and monitoring of the strand anchorage system of the Shahid Rajaei port harbour (phase 3), which is the first project of the harbour structural health monitoring project in Iran, has been discussed. Among the various control instrumentation used in the structural health monitoring system of the mentioned project, strain gauges with Fiber Bragg grating (FBG) mechanism have been introduced and the obtained results have been analyzed. According to the evaluation on the measurement data and the graphs of control parameters, it can be concluded that the anchorage system of the harbour structure is in a desired condition.   http://ijmt.ir/article-1-830-en.pdf Structural health monitoring Fiber optic sensor Strain gauge Harbour Anchorage eng Iranian Association of Naval Architecture & Marine Engineering International Journal of Maritime Technology 2345-6000 2476-5333 2024-05 20 13 25 article mohsen saeedi namini mohsen.saeedinamini@gmail.com 1 Ahmadreza Kohansal kohansal@pgu.ac.ir 2 Persian Gulf University Persian Gulf University In this study, the effect of hydrofoil stabilizer location on the porpoising instability of a mono-hull planing craft and also its optimal location have been investigated. The craft used in this project was a planing mono-hull one which was longitudinally unstable in the sea test. More precisely, it should be said that the craft entered the longitudinal instability stage at a speed of 30 knots and severe changes in its pitch and heave movements were observed. Numerical simulation which was based on computational fluid dynamics (CFD) techniques was done to simulate a three-dimensional geometric model in the fluid Eulerian two phases flow. A validation study was carried out by comparing the numerical results with the experimental data of the planing hull without the hydrofoil stabilizer. To study the effect of the installation position of the hydrofoil stabilizer, three parameters include depth of the hydrofoil relative to the transom bottom, the longitudinal distance of hydrofoil from the transom and the angle of attack were selected. The effects of changes in each of these parameters were investigated separately. Finally, the most suitable installation parameters that provide the best performance of the hydrofoil stabilizer and reduce the porpoising influence were selected. From the results of this study, it was observed that by increasing the depth of the hydrofoil from the transom and also by increasing the angle of attack of the hydrofoil, the amplitude of heave and pitch diagrams has decreased. The longitudinal distance of the hydrofoil to transom has not significant effect on porpoising instability. However, the results showed that the proper position for the hydrofoil stabilizer should not be under the hull bottom. http://ijmt.ir/article-1-832-en.pdf Porpoising Planing craft Mono-Hull Hydrofoil Stabilizer Dynamic Motions eng Iranian Association of Naval Architecture & Marine Engineering International Journal of Maritime Technology 2345-6000 2476-5333 2024-05 20 26 50 article elham Ghanbari Adivi elhamgh44@gmail.com 1 Associated professor, Shahrekord university Developing vegetation cover is one of the practical solutions to alleviate the sediment transfer rate. Predicting the sediment transfer rate in the presence of cover vegetation is a complicated necessary issue for designers due to the complex interaction between sediments and cover vegetation. This study intends to predict the sediment transfer rate (STR) by employing soft computing models based on an experimental study. The primary innovations in this study were the introduction of new and optimized versions of the group method of data handling (GMDH) for predicting sediment transport rate, the use of a new inclusive multiple model for predicting sediment transport rate, and the investigation of the effects of various parameters on the sediment transport rate, such as vegetation cover density. This study used an inclusive multiple model (IMM) as an ensemble model to predict sediment transport in the presence of cover vegetation. Initially, the sediment transport rate was predicted using the individual GMDH models. These outputs were then used to create the final outputs by inserting them into the GMDH model as an ensemble model at the next level. The Honey Badger algorithm (HBA), the rat swarm optimization algorithm (RSOA), the sine cosine algorithm (SCA), and the particle swarm optimization algorithm (PSOA) were used to train the GMDH model. The diameter of the sediments, the diameter of the stems, the density of vegetation cover, the wave height, the wave velocity, the cover height, and the wave force were used as inputs to the models. The IMM's mean absolute error (MAE) was 0.145 m3/s, while the MAEs for GMDH-HBA, GMDH-RSOA, GMDH-SCA, GMDH-PSOA, and GMDH in the testing level were 0.176 m3/s, 0.312 m3/s, 0.367 m3/s, 0.498 m3/s, and 0.612 m3/s, respectively. The Nash–Sutcliffe coefficient (NSE) of IMM, GMDH-HBA, GMDH-RSOA, GMDH-SCA, GMDH-PSOA, and GHMDH were 0.95 0.93, 0.89, 0.86, 0.82, and 0.76, respectively. Additionally, this study demonstrated that vegetation cover decreased sediment transport rate by 90%. The overall results indicated that the IMM and GMDH-HBA models could accurately predict sediment transport rates.   http://ijmt.ir/article-1-835-en.pdf Sediment transport rate Coastal regions Forest cover Group method of data handling Optimization Algorithms eng Iranian Association of Naval Architecture & Marine Engineering International Journal of Maritime Technology 2345-6000 2476-5333 2024-05 20 51 60 article Saeed Soheili soheili@iau.ac.ir 1 Seyyed Esmaeel Hosseini Hosseini.mec62@gmail.com 2 Abdollah Karimi abdollah.93.karimi.215@gmail.com 3 Assistant Professor, Department of Mechanical Engineering, Mashhad Branch, Islamic Azad University, Mashhad, Iran. MSc of Mechanical Engineering, Department of Mechanical Engineering, Imam Hossein University, Tehran, Iran. MSc of Mechanical Engineering, Department of Mechanical Engineering, Hakim Sabzevari University, Sabzevar, Iran. In this paper, the application of distributed-lumped (hybrid) modeling technique (DLMT) in the modeling of longitudinal (axial) vibration of marine shaft system is investigated. The equation of motion for the longitudinal vibration is solved in new analytical method, and modeled as a series of interconnected distributed and lumped elements. Natural frequencies of a rotor system with various elements are calculated based on the distributed lumped modeling technique (DLMT). The results obtained by this method are compared and verified with the results of other techniques, such as FEM, using ANSYS software, and the mode shapes are also presented. The method is then employed for calculating the natural frequencies of a marine propeller shaft with multiple elements such as different couplings. The results are compared and verified with the frequencies and mode shapes obtained by KissSoft software. It is shown that the presented method provides highly accurate results, while it can be simply and effectively applied to the complicated systems. http://ijmt.ir/article-1-844-en.pdf Longitudinal Vibration Hybrid Modeling Marine Propeller Shaft Distributed Element Lumped Element eng Iranian Association of Naval Architecture & Marine Engineering International Journal of Maritime Technology 2345-6000 2476-5333 2024-05 20 61 69 article Mohammadali Zarghami Mohamad.zarghami@gmail.com 1 Sadigh Raissi Raissi@azad.ac.ir 2 tohidi hamid htohidi1342@gmail.com 3 Shahrooz Bamdad sh.bamdad2000@yahoo.com 4 South Tehran Azad University South Tehran Azad University South Tehran Azad University South Tehran Azad University This study aims to enhance equipment management in grain unloading operations at Khuzestan Ports in Iran by predicting the remaining useful life of electric motors used in grain suction systems (neuero). Utilizing LSTM models in conjunction with environmental factors, this research minimizes unexpected costs associated with equipment failures and reduces downtime in unloading and loading processes. Real-world data from Khuzestan ports demonstrates the high accuracy of the LSTM model in predicting failures. The findings support proactive maintenance strategies, thereby improving efficiency and reliability in the port and maritime industry. While challenges such as limited data, incomplete coverage of environmental factors, and reliance on deep learning models exist, this study provides a foundation for future research on optimizing maintenance and management of neuero electric motors in bulk vessels. http://ijmt.ir/article-1-845-en.pdf Remaining Life Prediction Failure Process Modeling Neural Networks Artificial Intelligence Data-Driven Approach. eng Iranian Association of Naval Architecture & Marine Engineering International Journal of Maritime Technology 2345-6000 2476-5333 2024-05 20 70 77 article Alireza Asadi alireza_asadi90@yahoo.com 1 Kourosh Javaherdeh javaherdeh@guilan.ac.ir 2 Mohammad Naghashzadegan naghash@guilan.ac.ir 3 P.hd student, Campus faculty, University of Guilan Faculty of mechanical engineering, University of Guilan,Rasht,Iran. Faculty of Mechanical Engineering, University of Guilan, Iran. This article investigates the effect of using three nanofluids as exhaust gas cooling fluid in an EGR cooler. Reducing the exhaust temperature of diesel engines can reduce environmental and thermal pollutants. In a conventional 3-liter engine in all kinds of vehicles, 20 to 40 kW of its 115 kW power is being wasted. The engine shell temperature rises to 600 degrees Celsius.  Exhaust gas recirculation can recover a part of it. Exhaust gas recirculation can recover thermal energy by exhaust gas recirculation method by charging a thermal energy storage tank to feed a diesel engine in cold start.Many researchers have simulated natural convection in the nanofluids. The innovation of the current research is the use of 61 tubes inside the small heat exchanger that is cooled by the discussed nanofluids in the exhaust gas recirculation system of the diesel engine that works with the paraffin phase changer and the exhaust gas recirculation rate is 60% to Reduce of environmental pollution and smoother operation of diesel engine. The inlet is steady state turbulent. The thickness of the inner tubes is considered close to zero. The shell is adiabatic. Both of them exit the heat exchanger under pressure. Three nanoparticles of diamond, silicon dioxide, and copper are considered. This numerical simulation has solved the continuity equations, energy, Navier-Stokes, the pressure drop along the pipe, flow, and rotation equation, kinetic energy disturbance, and energy loss rate equation. The results showed a higher pressure drop for the silicon dioxide-ethylene glycol nanofluid. Silicon dioxide-ethylene glycol nanofluid has a higher Nusselt number, slightly different from other nanofluids. Also, Copper ethylene glycol has a lower Velocity among nanofluids http://ijmt.ir/article-1-843-en.pdf Numerical solution Nanofluids Cooling Diesel engines Shell and tube heat exchangers.