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Propeller connection to diesel engine in two shaft line designs of a catamaran passenger ship 2 2 The engine braking power moves the ship and it is converted into effective power by taking into account the propulsion power losses and the propeller efficiency. The braking power diagram must be in a suitable position relative to the continuous power diagram and the maximum power of the engine to ensure safe engine operation. In this paper, the propulsion system of a catamaran passenger vessel is investigated and the matching condition of the propulsion components in two shaft line designs and their impact on the performance of the engine and vessel are analyzed in detail. The hull is subjected to CFD analysis and the resistance is calculated. Then, using the hydrodynamic coefficients of the propeller, the matching calculations of the propeller to the engine have been done.  To match the propulsion system, the gearbox with 2.963:1 was coupled with the shaft line. The shaft line design is satisfactory in ship maneuvering and diesel engine performance. The ship's resistance was calculated by STAR-CCM+ software, used in matching calculations and the results have been validated by sea trials. The error between sea trial and matching calculations is a maximum of 7%. 1 10 2024/12/3 1403/9/13 2025/02/11 1403/11/23 mojtaba pakian mojtaba pakian SMI Bushehr shipyard ایران pakianm@chmail.ir Matching of Propulsion System Diesel engine Propeller Overload Over speed Woodward JB. Matching Engine and propeller. Univ., Department of Naval Architecture and Marine Engineering; 1976.##Marine Engines Application and Installation Guide. Caterpillar. 2000 Caterpillar Inc. Printed in U.S.A.##Samson N. World Journal of Engineering Research and Technology WJERT. World Journal of Engineering. 2017;3(1):161-77.##Grunditz G. Optimizing propeller and propulsion. The quest for reduced fuel consumption, emissions, and noise levels. Published in Marine Technology, January 2015. 2015.##Habibi, Nurhadi. Analysis of propeller type B- series selection on RO- RO 600 GT Ferry using Matchpro Application. Jurnal Ilmiah Teknologi Maritim Wave. Vol. 10 No.02; 2016. p. 75-81.##Abidin MZ, Adji SW. Analisa Performance Propeller B-series dengan pendekatan structure dan unstructure meshing. Jurnal Teknik ITS. 2012 Sep 11;1(1):G241-6.##Altosole M, Borlenghi M, Capasso M, Figari M. Computer-based design tool for a fuel efficient-low emissions marine propulsion plant. ICMRT Proceedings. 2007.##Pivano L. Thrust estimation and control of marine propellers in four-quadrant operations. Doctoral thesis. Fakultet for informasjonsteknologi, matematikk og elektroteknikk. 2008##Habibi, P., Nurhadi, H. 2016 Analysis of propeller type B- series selection on RO- RO 600 GT Ferry using Matchpro Application. J. Ilmiah Teknologi Maritim Wave. 10, 75-81.##Ogar OB, Nitonye S, John-Hope I. Design analysis and optimal matching of a controllable pitch propeller to the hull and diesel engine of a CODOG system. Journal of Power and Energy Engineering. 2018 Mar 29;6(03):53.##Nurhadi, Zen. H. Sumarsono. Study of Engine Propeller Matching for High-Speed Vessel with Gawn Series Propeller. EPI International Journal of Engineering. Vol. 1, No. 1, February 2018, pp. 39-42.##Gaggero S, Dubbioso G, Villa D, Muscari R, Viviani M. Propeller modeling approaches for off-design operative conditions. Ocean Engineering. 2019 Apr 15;178:283-305.##Pakian Bushehri M, Golbahar Haghighi MR. Experimental and numerical analysis of Hydrodynamic Characteristics of a surface piercing propeller mounted on high-speed craft. International Journal of Maritime Technology. 2021 Apr 10;15:79-91.##Bushehri MP, Haghighi MG. Propulsion System Matching Analysis of a Catamaran Passenger Ship by Changing the Gear Ratio. Iranian Journal of Science and Technology, Transactions of Mechanical Engineering. 2023 Mar;47(1):91-107.##Tran TG, Kim HC. A study on the matching problem of engine, propeller, and ship hull under actual service conditions. International Journal of Naval Architecture and Ocean Engineering. 2023 Jan 1;15:100538.##Tan Q, Sui C, Ding Y, Liu H, Gao C. Effect of Shaft System Arrangements on Ship-Engine-Propeller Matching. InInternational Conference on Marine Equipment & Technology and Sustainable Development 2023 Apr 1 (pp. 668-687). Singapore: Springer Nature Singapore.##Bayraktar M, Göksu B, Yüksel O. Matching of propulsion system components for a planing hull model. Ships and Offshore Structures. 2024 May 29:1-2.##Ramadhan BR, Purwana A. Investigating the Engine Propeller Matching of Triple Screw Ro-Ro Passenger Ship. In International Conference on Maritime Technology and Its Application 2025 Jan 17 (Vol. 1, No. 1, pp. 1-9).##Orca3D User Manual. Leveraging the power of Rhino for the naval architect. Version 1.3.4. © 2018-2024 by Orca3D##STAR CCM+. Product Version of Simcenter STAR-CCM+ Build 14.02.010. Documentation- version 2019.1. NY, USA.##Tezdogan T, Demirel YK, Kellett P, Khorasanchi M, Incecik A, Turan O. Full-scale unsteady RANS CFD simulations of ship behaviour and performance in head seas due to slow steaming. Ocean Engineering. 2015 Mar 15;97:186-206.##Khazaee R, Rahmansetayesh MA, Hajizadeh S. Hydrodynamic evaluation of a planing hull in calm water using RANS and Savitsky's method. Ocean Engineering. 2019 Sep 1;187:106221.##Molland AF, Turnock SR, Hudson DA. Ship resistance and propulsion. Cambridge university press; 2017 Aug 17.##MTU Diesel Engine. Operation and Manual of 12v396. © 2013 Copyright MTU Friedrichshafen, Rechtsform: GmbH. www.mtu-solutions.com.##LR. Rules and Regulation for the Classification of Ships. Part 5 Main and Auxiliary engine. July 2016## ##

Hydrodynamic Performance and Stability Optimization of High-Speed Monohull Vessels with Chine Hulls: A Computational and Experimental Approach 2 2 High-speed monohull vessels with chine hulls are widely used due to their simple design, but maintaining optimal performance at high speeds requires precise hull force analysis. This study utilizes 3D scanning to capture hull geometry, refining it in AutoCAD for efficiency. Hydrostatic and hydrodynamic assessments are conducted using Maxsurf, applying the Switkowski method. The study examines vessel motion, crew comfort, and water ingress under different sea conditions. Results indicate that at a 5.4-degree trim, pitch motion intensifies in harmonic waves, yaw motion increases in beam waves, and pitch and heave motions are more pronounced in head waves. Water ingress becomes a concern at this trim in Beaufort 2 and 3, with MSI peaking at 12.5% in Beaufort 3. The lowest resistance occurs at 5.22 knots, but higher trims raise power demands. Manual trim adjustments using outboard engines and jacks effectively mitigate these effects. 12 27 2024/12/32025/02/2 1403/11/14 2025/02/112025/05/27 1404/3/6 Seyed Reza Samaei Seyed Reza Samaei Assistant professor, Technical and Engineering Faculty, Science and Research Branch, Islamic Azad University, Tehran, Iran; samaei@srbiau.ac.ir ایران samaei@srbiau.ac.ir Mohammad Asadian Ghahfarokhi Mohammad Asadian Ghahfarokhi Assistant professor, Department of Marine industries, Science and Research Branch, Islamic Azad University, Tehran, Iran; m.asadian@srbiau.ac.ir ایران m.asadian@srbiau.ac.ir high-speed vessel hydrostatics hydrodynamics crew sea conditions water ingress Brown, P. W. (1971). An experimental and theoretical study of planning surfaces with trim flaps. Davidson Laboratory Technical Report.##Savitsky, D., & Brown, P. W. (1975). Procedures for hydrodynamic evaluation of planning hulls in smooth and rough water. In Proceedings of Hampton Road Section, SNAME (November 1975).##Dawson, D., & Blount, D. (2002). Trim control. Professional Boat Builder, N75.##Bizzolara, S. (2003). Hydrodynamic analysis of interceptors with CDF methods. In Proceedings Fast 2003, 7th Int. Conference on Fast Sea Transportation (Vol. 3, pp. E.49-E.56).##Molini, A., & Brizzolara, S. (2005). Hydrodynamics of interceptors: A fundamental study. In Proceeding ICMRT2005, Int Conference on Maritime Research and Transportation, Ischia (Naples), Italy (Vol. 1).##Villa, D., & Brizzolara, S. (2009). A systematic CFD analysis of flaps/interceptor's hydrodynamic performance. In Fast 2009, Athens, October 2009.##Steen, S., Alterskjar, S. A., Velgaard, A., & Aasheim, I. (2009). Performance of a planning craft with mid-mounted interceptor. In Fast 2009, Greece, October 2009.##Hansvic, T. (2005). Resistance of planning catamaran with step (MSc thesis). Department of Marine Technology, NTNU, Trondheim, Norway.##Hansvic, T., & Steen, S. (2006). Use of interceptors and stepped hull to improve performance of high-speed planning catamaran. In Int. Conf. on High-Speed Craft-ACV's Wig'd and Hydrofoils, Royal Institute of Naval Architecture, 31 Oct.-1 Nov., 2006, London, UK.##Fridman, G. (1969). Theory and practice of application of the interceptors on high-speed ships. In Fast 2007, Shanghai.##Chambliss, D. B., & Boyd, G. M., Jr. (1953). The planning characteristics of two V-shaped prismatic surfaces having angles of deadrise of 20° and 40°. NACA TN No.2876, January 1953.##Savirsky, D., & Neidlinger, J. W. (1954). Wetted area and center of pressure of planning surfaces at very low speed coefficients. Stevens Institute of Technology, Davidson Laboratory Report No.493, July 1954.##Savitsky, D., & Ross, E. (1952). Turbulence stimulation in the boundary layer of planning surfaces. Stevens Institute of Technology, Davidson Laboratory Report 44, August 1952.##Sottorf, W. (1932). Experiments with planning surfaces. NACA TM 661.##Locker, F. W. S., Jr. (1948). Tests of a flat bottom planning surface to determine the inception of planning. Navy Department, BuAer, Research Division Report No.1996, December 1948.##Sottorf, W. (1949). Systematic model researches on the stability limits of the DVI series of flow designs. NACA TM 1254, December 1949.##Davidson, K. S. M., & Locker, F. W. S., Jr. (1943). Some systematic model experiments on the porpoising characteristics of flying boat hulls. NACA ARR, June 1943.##Benson, J. M. (1942). The effect of deadrise upon the low-angle type of porpoising. NACA ARR, October 1942.##Parkinson, J. B., & Olson, R. E. (1944). Tank tests of an army OA-9 amphibian. NACA ARR, December 1944.##Locker, F. W. S., Jr. (1943). General porpoising tests of flying-boat hull models. NACA ARR, September 1943.##Karafitah, G., & Fisher, S. C. (1987). The effect of stern wedges on ship powering performance. Naval Engineers Journal, May 1987.##Wang, C. T. (1980). Wedge effect on planning hulls. J. Hydronautics, Vol. 14, No. 4, 1980.##Cuasanelli, D. S., & Cave, W. L. (1993). Effect of stern flaps on powering performance of the FFG-7 class. Marine Technology, Vol. 30, No. 1, Jan. 1993.##Cuasanelli, D. S., & Karafiath, G. (2001). Advances in stern flap design and application. In Fast 2001, Southampton, UK, Sep. 2001.##Tsai, J. F., & Huang, J. K. (2003). Study on the effect of interceptor on high-speed craft. Journal of Society of Naval Architects and Marine Engineers, Roc, Vol. 22, No. 2, 2003, pp. 95-101.##Karimi, M. H. (2006). Hydrodynamic quality improvement techniques for high-speed planning crafts. In 7th Conference on Marine Industries, Tehran, Jan. 2006.##KSRI. (Year not provided). A radically new system for high-speed ship motion stabilization and speed increase based on automatically controlled interceptors, Report.2.##KSRI. (2004). A radically new system for high-speed ship motion stabilization and speed increase of oscillations of high-speed catamarans, Report.2004.##Karimi, M. H., Seif, M. S., & Abbaspoor, M. (2013). An experimental study of interceptor's effectiveness on hydrodynamic performance of high-speed planning crafts. Polish Maritime Research, 2(78), 2013, Vol. 20, pp. 21-29. DOI: 10.2478/pomr-2013-0013.##Schlichting, H. (1979). Boundary Layer Theory (7th ed.). McGraw-Hill Inc.##Interceptor Guide. (2011). Retrieved from http://www.humphree.com, March 15, 2011.##Day, A. H., & Cooper, C. (2011). An experimental study of interceptors for drag reduction on high-performance sailing yachts. Ocean Engineering, Vol. 38, pp. 983-994.##ITTC Recommended 2002 (for HSC model test).##Teimouri, M. (2009). The Effect of Spray Rails and Transverse Steps on High-Speed Vessels (Master's thesis).##Seyed Reza Samaei, Madjid Ghodsi Hassanabad, Mohammad Asadian ghahfarrokhi, Mohammad Javad Ketabdari, "Numerical and experimental investigation of damage in environmentally-sensitive civil structures using modal strain energy (case study: LPG wharf)". Int. J. Environ. Sci. Technol. 18, 1939-1952 (2021).##Samaei, S. R., Azarsina, F., & Ghahferokhi, M. A. (2016). Numerical simulation of floating pontoon breakwater with ANSYS AQWA software and validation of the results with laboratory data. Bulletin de la Société Royale des Sciences de Liège, 85, 1487-1499.##Samaei, S. R., Asadian Ghahferokhi, M., & Azarsinai, F. (2022). Experimental study of two types of simple and step floating pontoon breakwater in regular waves. International Journal of Marine Science and Environment, 6(1), 8-16.##Samaei, S. R., & Ghodsi Hassanabad, M. (2022). Damage location and intensity detection in tripod jacket substructure of wind turbine using improved modal strain energy and genetic algorithm. Journal of Structural and Construction Engineering, 9(4), 182-202. doi: 10.22065/jsce.2021.294103.2488##Samaei, S. R., Ghodsi Hassanabad, M., Asadian Ghahfarrokhi, M., & Ketabdari, M. J. (2021). Numerical and experimental study to identify the location and severity of damage at the pier using the improved modal strain energy method-Case study: Pars Asaluyeh LPG export pier. Journal of Structural and Construction Engineering, 8(Special Issue 3), 162-179. doi: 10.22065/jsce.2020.246425.2225##Samaei, S. R., Ghodsi Hassanabad, M., Asadian Ghahfarrokhi, M., & Ketabdari, M. J. (2020). Structural health monitoring of offshore structures using a modified modal strain energy method (Case study: four-leg jacket substructure of an offshore wind turbine). Journal Of Marine Engineering, 16(32), 119-130.##Samaei, S. R., Ghodsi Hassanabad, M., & Karimpor Zahraei, A. (2021). Identification of Location and Severity of Damages in the Offshore wind Turbine Tripod Platform by Improved Modal Strain Energy Method. Analysis of Structure and Earthquake, 18(3), 51-62.##Samaei, S. R., Ghodsi Hassanabad, M., Asadian Ghahfarrokhi, M., & Ketabdari, M. J. (2021). Investigation of location and severity of damage in four-legged offshore wind turbine stencil infrastructure by improved modal strain energy method. Analysis of Structure and Earthquake, 17(3), 79-90.##Seyed Reza Samaei, Farhood Azarsina, Mohammad Asadian. " Numerical simulation of floating pontoon breakwater with Ansys Aqua software and validation of results with laboratory data.", The third national conference on recent innovations in civil engineering, architecture and urban planning, 2016.## ##

Parameter study for enhancing the speed of a high-speed craft prototype with adequate maneuverability 2 2 The demand for high-speed crafts has grown rapidly due to their strategic importance and quick response capabilities. Governments prioritize their development through research and industry advancements. Designing a high-speed craft exceeding 60 knots requires significant time and cost. This study identifies key factors for optimizing speed and maneuverability through hull modifications, chine positions, indentations, propulsion systems, and initial trim adjustments. The sample craft was 3D scanned, and simulations were conducted using MAXSURF. The hull was modified and uniformly adjusted, followed by hydrostatic and hydrodynamic calculations. Findings indicate that achieving speeds above 60 knots require a minimum initial trim of 0.4° at the transom. Proper hull line adjustments and equipment placement were essential. Additionally, with a safety factor of 1.25, the craft requires approximately 600 horsepower for the desired speed. These optimizations ensure efficient performance while minimizing costs.   28 43 2024/12/32025/02/22025/02/2 1403/11/14 2025/02/112025/05/272025/05/27 1404/3/6 Seyed Reza Samaei Seyed Reza Samaei Assistant professor, Technical and Engineering Faculty, Science and Research Branch, Islamic Azad University, Tehran, Iran; samaei@srbiau.ac.ir ایران samaei@srbiau.ac.ir Mohammad Asadian Ghahfarokhi Mohammad Asadian Ghahfarokhi Assistant professor, Department of Marine industries, Science and Research Branch, Islamic Azad University, Tehran, Iran; m.asadian@srbiau.ac.ir ایران m.asadian@srbiau.ac.ir High-speed craft hydrostatics maneuverability fiberglass boat trim angle Brown, P. W. (1971). An experimental and theoretical study of planning surfaces with trim flaps. Davidson Laboratory Technical Report.##Savitsky, D., & Brown, P. W. (1975). Procedures for hydrodynamic evaluation of planning hulls in smooth and rough water. In Proceedings of Hampton Road Section, SNAME (November 1975).##Dawson, D., & Blount, D. (2002). Trim control. Professional Boat Builder, N75.##Bizzolara, S. (2003). Hydrodynamic analysis of interceptors with CDF methods. In Proceedings Fast 2003, 7th Int. Conference on Fast Sea Transportation (Vol. 3, pp. E.49-E.56).##Molini, A., & Brizzolara, S. (2005). Hydrodynamics of interceptors: A fundamental study. In Proceeding ICMRT2005, Int Conference on Maritime Research and Transportation, Ischia (Naples), Italy (Vol. 1).##Villa, D., & Brizzolara, S. (2009). A systematic CFD analysis of flaps/interceptor's hydrodynamic performance. In Fast 2009, Athens, October 2009.##Steen, S., Alterskjar, S. A., Velgaard, A., & Aasheim, I. (2009). Performance of a planning craft with mid-mounted interceptor. In Fast 2009, Greece, October 2009.##Hansvic, T. (2005). Resistance of planning catamaran with step (MSc thesis). Department of Marine Technology, NTNU, Trondheim, Norway.##Hansvic, T., & Steen, S. (2006). Use of interceptors and stepped hull to improve performance of high-speed planning catamaran. In Int. Conf. on High-Speed Craft-ACV's Wig'd and Hydrofoils, Royal Institute of Naval Architecture, 31 Oct.-1 Nov., 2006, London, UK.##Fridman, G. (1969). Theory and practice of application of the interceptors on high-speed ships. In Fast 2007, Shanghai.##Chambliss, D. B., & Boyd, G. M., Jr. (1953). The planning characteristics of two V-shaped prismatic surfaces having angles of deadrise of 20° and 40°. NACA TN No.2876, January 1953.##Savirsky, D., & Neidlinger, J. W. (1954). Wetted area and center of pressure of planning surfaces at very low speed coefficients. Stevens Institute of Technology, Davidson Laboratory Report No.493, July 1954.##Savitsky, D., & Ross, E. (1952). Turbulence stimulation in the boundary layer of planning surfaces. Stevens Institute of Technology, Davidson Laboratory Report 44, August 1952.##Sottorf, W. (1932). Experiments with planning surfaces. NACA TM 661.##Locker, F. W. S., Jr. (1948). Tests of a flat bottom planning surface to determine the inception of planning. Navy Department, BuAer, Research Division Report No.1996, December 1948.##Sottorf, W. (1949). Systematic model researches on the stability limits of the DVI series of flow designs. NACA TM 1254, December 1949.##Davidson, K. S. M., & Locker, F. W. S., Jr. (1943). Some systematic model experiments on the porpoising characteristics of flying boat hulls. NACA ARR, June 1943.##Benson, J. M. (1942). The effect of deadrise upon the low-angle type of porpoising. NACA ARR, October 1942.##Parkinson, J. B., & Olson, R. E. (1944). Tank tests of an army OA-9 amphibian. NACA ARR, December 1944.##Locker, F. W. S., Jr. (1943). General porpoising tests of flying-boat hull models. NACA ARR, September 1943.##Karafitah, G., & Fisher, S. C. (1987). The effect of stern wedges on ship powering performance. Naval Engineers Journal, May 1987.##Wang, C. T. (1980). Wedge effect on planning hulls. J. Hydronautics, Vol. 14, No. 4, 1980.##Cuasanelli, D. S., & Cave, W. L. (1993). Effect of stern flaps on powering performance of the FFG-7 class. Marine Technology, Vol. 30, No. 1, Jan. 1993.##Cuasanelli, D. S., & Karafiath, G. (2001). Advances in stern flap design and application. In Fast 2001, Southampton, UK, Sep. 2001.##Tsai, J. F., & Huang, J. K. (2003). Study on the effect of interceptor on high-speed craft. Journal of Society of Naval Architects and Marine Engineers, Roc, Vol. 22, No. 2, 2003, pp. 95-101.##Karimi, M. H. (2006). Hydrodynamic quality improvement techniques for high-speed planning crafts. In 7th Conference on Marine Industries, Tehran, Jan. 2006.##KSRI. (Year not provided). A radically new system for high-speed ship motion stabilization and speed increase based on automatically controlled interceptors, Report.2.##KSRI. (2004). A radically new system for high-speed ship motion stabilization and speed increase of oscillations of high-speed catamarans, Report.2004.##Karimi, M. H., Seif, M. S., & Abbaspoor, M. (2013). An experimental study of interceptor's effectiveness on hydrodynamic performance of high-speed planning crafts. Polish Maritime Research, 2(78), 2013, Vol. 20, pp. 21-29. DOI: 10.2478/pomr-2013-0013.##Schlichting, H. (1979). Boundary Layer Theory (7th ed.). McGraw-Hill Inc.##Interceptor Guide. (2011). Retrieved from http://www.humphree.com, March 15, 2011.##Day, A. H., & Cooper, C. (2011). An experimental study of interceptors for drag reduction on high-performance sailing yachts. Ocean Engineering, Vol. 38, pp. 983-994.##ITTC Recommended 2002 (for HSC model test).##Teimouri, M. (2009). The Effect of Spray Rails and Transverse Steps on High-Speed Vessels (Master's thesis).##Seyed Reza Samaei, Madjid Ghodsi Hassanabad, Mohammad Asadian ghahfarrokhi, Mohammad Javad Ketabdari, "Numerical and experimental investigation of damage in environmentally-sensitive civil structures using modal strain energy (case study: LPG wharf)". Int. J. Environ. Sci. Technol. 18, 1939-1952 (2021).##Samaei, S. R., Azarsina, F., & Ghahferokhi, M. A. (2016). Numerical simulation of floating pontoon breakwater with ANSYS AQWA software and validation of the results with laboratory data. Bulletin de la Société Royale des Sciences de Liège, 85, 1487-1499.##Samaei, S. R., Asadian Ghahferokhi, M., & Azarsinai, F. (2022). Experimental study of two types of simple and step floating pontoon breakwater in regular waves. International Journal of Marine Science and Environment, 6(1), 8-16.##Samaei, S. R., & Ghodsi Hassanabad, M. (2022). Damage location and intensity detection in tripod jacket substructure of wind turbine using improved modal strain energy and genetic algorithm. Journal of Structural and Construction Engineering, 9(4), 182-202. doi: 10.22065/jsce.2021.294103.2488##Samaei, S. R., Ghodsi Hassanabad, M., Asadian Ghahfarrokhi, M., & Ketabdari, M. J. (2021). Numerical and experimental study to identify the location and severity of damage at the pier using the improved modal strain energy method-Case study: Pars Asaluyeh LPG export pier. Journal of Structural and Construction Engineering, 8(Special Issue 3), 162-179. doi: 10.22065/jsce.2020.246425.2225##Samaei, S. R., Ghodsi Hassanabad, M., Asadian Ghahfarrokhi, M., & Ketabdari, M. J. (2020). Structural health monitoring of offshore structures using a modified modal strain energy method (Case study: four-leg jacket substructure of an offshore wind turbine). Journal Of Marine Engineering, 16(32), 119-130.##Samaei, S. R., Ghodsi Hassanabad, M., & Karimpor Zahraei, A. (2021). Identification of Location and Severity of Damages in the Offshore wind Turbine Tripod Platform by Improved Modal Strain Energy Method. Analysis of Structure and Earthquake, 18(3), 51-62.##Samaei, S. R., Ghodsi Hassanabad, M., Asadian Ghahfarrokhi, M., & Ketabdari, M. J. (2021). Investigation of location and severity of damage in four-legged offshore wind turbine stencil infrastructure by improved modal strain energy method. Analysis of Structure and Earthquake, 17(3), 79-90.##Seyed Reza Samaei, Farhood Azarsina, Mohammad Asadian. " Numerical simulation of floating pontoon breakwater with Ansys Aqua software and validation of results with laboratory data.", The third national conference on recent innovations in civil engineering, architecture and urban planning, 2016.## ##

Investigation on hydrodynamic effects of using a supercavitating section in surface piercing hydrofoils 2 2 The purpose of this paper was to numerically investigate the effects of using supercavitation sections in ventilated semi-submerged hydrofoils. Studying the flow around such hydrofoils is often very complicated due to its multiphase nature and the simultaneous occurrence of cavitation and ventilation phenomena. The desired foil was the Waid section foil which has been examined at different attack angles and for different cavitation numbers. In this numerical simulation, the RANSE finite volume solver along with the VOF method have been used to model the multiphase flow around the semi-submerged hydrofoil. According to the obtained results, the formation of cavitation bubbles and the formation of ventilation around a supercavitating section is different from the conventional sections in semi-immersed foils. This could be due to the specific geometric shape of the supercavitating sections, especially in their front area. The pressure and flow contours around the hydrofoil have been predicted in semi-submerged form, and the ventilating air flow around the hydrofoil has also been investigated. Also, it has shown that the effect of cavitation at high speeds causes the formation of continuous bubbles, which will lead to the reduction of drag coefficients and increase the efficiency of supercavitating hydrofoils. According to the results obtained in this simulation, by increasing the cavitation number, the drag coefficient also increases in proportion to the lift coefficient. This process continues until the foil enter the completely wet phase, which with this phase change, the lift-to-drag coefficient ratio also decreases. Therefore, due to its high efficiency, the Waid section, is recommended for the design of surface piercing hydrofoils. 44 53 2024/12/32025/02/22025/02/22025/04/9 1404/1/20 2025/02/112025/05/272025/05/272025/06/17 1404/3/27 Mohammad Amin Esabat Mohammad Amin Esabat Department of Marine Engineering, Persian Gulf University ایران m.amin.esabat@gmail.com Ahmadreza Kohansal Ahmadreza Kohansal Department of Marine Engineering, Persian Gulf University ایران kohansal@pgu.ac.ir Super-cavitation Hydrofoil Surface piercing Ventilation Waid, R.L., Lindberg, Z., Experimental and theoretical investigations of a supercavitating hydrofoil (1957)##Afkar, H., Numerical simulation of flow with cavitation on ringed cavitator (2013)##Tachmindji, A., Morgan, W., The design and estimated performance of a series of supercavitating propellers. In: Proc. of 2nd Office of Naval Research Symposium on Naval Hydrodynamics, pp. 489-532 (1958)##Olofsson, N., Letter to the author and dr. s. a. kinnas (2001)##Kermeen, R.W., Naca 4412 and walchner profile 7 hydrofoils in non-cavitating and cavitating flows. Rep. No 47, 1-21 (1956)##Yao-tsu Wu, T., A free streamline theory for two-dimensional fully cavitated hydrofoils (1955)##Furuya, Okitsugu. ''Nonlinear calculation of arbitrarily shaped supercavitating hydrofoils near a free surface." Journal of Fluid Mechanics 68, no. 1 (1975): 21-40.##K. L. Wadlin, "Mechanics of ventilation inception," in Proceedings of the 2nd Symposium on Naval Hydrodynamics (Washington, DC, 1958), pp. 425-445.##J. P. Breslin and R. Skalak, "Exploratory study of ventilated flows about yawed surface-piercing struts," NASA Technical Memorandum, Washington, DC, Technical Report No. 2-23-59W, 1959.##K. I. Matveev, M. P. Wheeler, and T. Xing, "Numerical simulation of air ventilation and its suppression on inclined surface-piercing hydrofoils," Ocean Eng. 175, 251-261 (2019)##S. Brizzolara and D. Villa, "Three phases RANSE calculations for surface-piercing supercavitating hydrofoils," in Proceedings of the 8th International Symposium on Cavitation (Singapore, 2012).##C. Xu, J. Huang, Y. W. Wang, X. C. Wu, C. G. Huang, and X. Q. Wu, "Supercavitating flow around high-speed underwater projectile near free surface induced by air entrainment," AIP Adv. 8, 035016 (2018).##S. T. Chen, W. W. Zhao, and D. C. Wan, "CFD study of free surface effect on flow around a surface-piercing cylinder," in Proceedings of the 14th ISOPE Pacific-Asia Offshore Mechanics Symposium (Dalian, China, 2020).##R. L. Waid, Z. Lindberg, Experimental and theoretical investigations of a Supercavitating hydrofoil (1957).##R. W. Kermeen, Experimental investigations of three-dimensional effects on cavitating hydrofoils (1960).##B. R. Parkin, Experiments on circular arc and flat plate hydrofoils in Non-cavitating and full cavity flows (1956).##V. E. Johnson, Theoretical determination of low-drag supercavitating hydrofoils and their two-dimensional characteristics at zero cavitation number, National Advisory Committee for Aeronautics, 1957.##M. P. Tulin, Supercavitating flows - small perturbation theory, Journal of Ship Research 7 (1964) 16-37.##N. E. Fine, S. Kinnas, A boundary element method for the analysis of the flow around 3-d cavitating hydrofoils, Journal of ship research 37 (1993) 213-224.##S. Mishima, S. A. Kinnas, A numerical optimization technique applied to the design of two-dimensional cavitating hydrofoil sections, Journal of ship research 40 (1996) 28-38.##Y. Young, S. Kinnas, Analysis of supercavitating and surface-piercing propeller flows via bem, Computational Mechanics 32 (2003) 269-280.##J. Royset, L. Bonfiglio, G. Vernengo, S. Brizzolara, Risk-adaptive set based design and applications to shaping a hydrofoil, Journal of Mechanical Design 139 (2017) 101403##Brizzolara, Stefano," A new family of dual-mode supercavitating hydrofoils." Fourth International Symposium on Marine Propulsors. 2015.##G. Vernengo, L. Bonfiglio, S. Gaggero, S. Brizzolara, Physics-based design by optimization of unconventional supercavitating hydrofoils, Journal of Ship Research 60 (2016) 187-202.##https://doi.org/10.5957/jsr.2016.60.4.187##Y. Wang; C. Huang; T. Du; R. Huang, Y. Zhi; Y. Wang, Z. Xiao, Z. Bian, "Research on ventilation and supercavitation mechanism of high-speed surface-piercing hydrofoil", Physics of Fluids, 34, 023316 (2022)##Ferziger, J.H., Peric, M., Computational methods for fluid dynamics. 3rd rev. ed., Springer-Verlag, Berlin (2002)##Koop, A.H., Hoeijmakers, H., Numerical simulatin of unsteady three-dimensional sheet cavitation. University of Twente Enschede, The Netherlands (2008)##Harwood, C., The hydrodynamic and hydro-elastic responses of rigid and flexible surface piercing hydrofoils in multi-phase flows. Ph.D. thesis (2016)##Young, Y.L.J., Numerical modeling of supercavitating and surface-piercing propellers. The University of Texas at Austin (2002)## ##

Comparing the Effect of Duct Inlet Length on the Hydrodynamic Performance and Open Water Efficiency of a Pre-Swirl PumpJet Propulsion System with Experimental Method and Uncertainty Analysis 2 2 This study investigates the effect of duct inlet length on the hydrodynamic performance of a pre-swirl pump-jet system, focusing on open water efficiency through uncertainty analysis. To this end, five models with varying duct inlet lengths (0~0.1DRotor) were experimentally tested in the cavitation tunnel at Imam Khomeini Naval University in Noshahr. Sampled parameters included rotor thrust, combined duct and stator thrust, and rotor torque at eight advance ratios (J). Each measurement was repeated four times, and their averaged values were utilized in the calculations. Sensitivity analysis revealed that torque has a more significant impact on open-water efficiency compared to total thrust. Experimental test results demonstrated that the open water efficiency for all configurations reached a maximum at J=1.1. The L=0.1DR configuration exhibited the highest efficiency at 62.15%, representing a 5.15% improvement over the L=0DR configuration. The relative uncertainty of efficiency was below 5%, and the L=0.1DR configuration showed the smallest uncertainty range, indicating high experimental precision. Furthermore, an examination of the open water efficiency uncertainty range revealed that for advance ratios of 0.6, 1.1, and 1.4, the L=0.1DR configuration yielded the widest efficiency range. The upper bound of open water efficiency also belonged to the L=0.1DR configuration for other advance ratios. Therefore, based on the results of the conducted uncertainty analysis, the L=0.1DR configuration demonstrates improved open water efficiency performance compared to other configurations. This improvement is attributed to increased thrust resulting from better uniformity of the flow entering the stator and optimized angle of attack to the rotor blades.   54 70 2024/12/32025/02/22025/02/22025/04/92025/05/23 1404/3/2 2025/02/112025/05/272025/05/272025/06/172025/07/8 1404/4/17 MohammadHussein Qaedsharaf MohammadHussein Qaedsharaf PhD. student, Faculty of Mechanical Engineering, Malek-Ashtar University of Technology; Iran, Isfahan. ایران mqaed1100@gmail.com Ehsan Yari Ehsan Yari Assistant Professor, Faculty of Mechanical Engineering, Malek-Ashtar University of Technology; Iran, Isfahan. ایران Ehsanyari11@gmail.com Mojtaba Dehghan Manshadi Mojtaba Dehghan Manshadi Professor, Faculty of Mechanical Engineering, Malek-Ashtar University of Technology; Iran, Isfahan. ایران dehghanmanshadi@gmail.com Pre-swirl PumpJet Duct Inlet Length Stator-Rotor Distance Hydrodynamic Performance Open-Water Efficiency Uncertainty Analysis A comparison of pump jets and propellers for non-nuclear submarine propulsion Aidan Morrison January 2018##Renilson MR (2018) Submarine hydrodynamics, 2nd edn. Springer, Cham.##A.Dean, D.Voss, Design and Analysis of Experiments, Springer Verlag: New York,1999.##Insttrumentation Measurement And Analysis, 4Th Edn, by B.C. Nakra And K.K. Chaudhry.2016##H.W.Coleman, W.G.Steele, Experimentation and Uncertainty Analysis for Engineers", John Wiley and Sons, Inc., New York.1999##Analysis of heat transfer and fuel regression rate of solid fuel in hybrid thrusters [M.Sc.Thesis], Researcher Mohammad Hossein Qaedsharaf, Islamic Azad University, Science & Research Branch, 2011##Motallebi-Nejad, M., Bakhtiari, M., Ghassemi, H. et al. Numerical analysis of ducted propeller and pumpjet propulsion system using periodic computational domain. J Mar Sci Technol 22, 559-573 (2017).##Ghaedsharf, Mohammad Hossein, Ehsan, Mahdavi, Hadi and Mehrabi Gohari. (2019). Comparison of performance and sensitivity of effective parameters in two propellants hydrogen peroxide and nitrous oxide using uncertainty analysis. Mechanical Engineering, University of Tabriz, 50(3), 233-237. doi: https://10.22034/jmeut.2020.9802##Wang, C., Weng, K., Guo, C. et al. Analysis of influence of duct geometrical parameters on pump jet propulsor hydrodynamic performance. J Mar Sci Technol 25, 640-657 (2020).##Huang, Q., Li, H., Pan, G., & Dong, X. (2021). Effects of duct parameter on pump-jet propulsor unsteady hydrodynamic performance. Ocean Engineering, 221, 108509.‌##Chen, X., Cheng, L., Wang, C., & Luo, C. (2021). Influence of inlet duct length on the hydraulic performance of the waterjet propulsion device. Shock and Vibration, 2021(1), 6676601.##Zhou, Y., Pavesi, G., Yuan, J., & Fu, Y. (2022). A Review on Hydrodynamic Performance and Design of Pump-Jet: Advances, Challenges and Prospects. Journal of Marine Science and Engineering, 10(10), 1514##Zhou, Y., Pavesi, G., Yuan, J., Fu, Y., & Gao, Q. (2023). Effects of duct profile parameters on flow characteristics of pump-jet: A numerical analysis on accelerating and decelerating ducts distinguished by cambers and angles of attack. Ocean Engineering, 281, 114733.##Ji, X. Q., Zhang, X. S., Yang, C. J., & Dong, X. Q. (2024). Experimental and numerical investigation of the impacts of rotor tip-rake on excitation forces of pump-jet propulsors. Journal of Hydrodynamics, 1-16.##Zou, D., Xue, L., Lin, Q., Xu, J., Dong, X., Ta, N., & Rao, Z. (2024). Influence of propulsion shafting longitudinal vibration on the excitation force and vortex dynamics characteristics of pump-jet propulsor. Ocean Engineering, 295, 116962.‌##Weng, K., Sun, C., Han, K., Wang, C., Sun, S., Li, P., & Hu, J. (2024). Experimental/numerical investigation on the hydrodynamic and noise characteristics of pump-jet propulsion. Ocean Engineering, 307, 117995.‌##Zhou, Y., Pavesi, G., Yuan, J., Fu, Y., & Gao, Q. (2024). Effects of duct profile parameters on flow characteristics of pump-jet: A numerical analysis on accelerating and decelerating ducts distinguished by cambers and angles of attack. Ocean Engineering, 281, 114733.‌##Qaedsharaf, M. H., Yari, E., & Manshadi, M. D. (2025). Cavitation on the pump jet pre swirl type due to changes in the stator chord length. Physics of Fluids, 37(3).‌##Carlton, J. S., Marine propellers and propulsion, third ed., Amsterdam, Netherland, Elsevier (2012)##Bertram, V., Practical ship hydrodynamics Oxford, U.K, Butterworth Heinemann (2012)## ##

AI-Driven Ship Resistance Prediction Using Three Key Hydrodynamic Parameters 2 2 This paper introduces an innovative, AI-driven methodology for predicting ship resistance using only three fundamental input parameters: Length Between Waterlines (LWL), Beam at Waterline (BWL), and Draft (T). Traditional resistance prediction techniques such as empirical methods, towing tank experiments, and computational fluid dynamics (CFD) simulations are highly accurate but involve significant time, cost, and complexity. Our approach leverages machine learning algorithms, including XGBoost, CatBoost, and Gradient Boosting, to derive a comprehensive suite of hydrodynamic characteristics from a robust dataset comprising 308 full-scale experiments across 22 different hull shapes. The methodology begins with meticulous data preprocessing and feature engineering, including normalization, outlier analysis, and correlation assessment, to ensure reliability and minimize error propagation. By transforming raw hydrodynamic data into dimensionless groups, our models effectively capture both linear and non-linear relationships among critical parameters such as displacement, wetted surface area, midship section area, waterplane area, and the longitudinal center of buoyancy (LCB). Simple linear regression techniques were successfully used to derive parameters with perfect correlations, while more complex non-linear interactions were accurately predicted using advanced ensemble methods. The integration of these AI models into a Django-based web application further enhances the utility of our approach, providing naval architects and marine engineers with a user-friendly, real-time tool for design optimization and performance evaluation. Comparative analysis indicates that our streamlined model delivers predictions of residual and frictional resistance with accuracy comparable to traditional methods, while offering significant improvements in computational efficiency and cost-effectiveness. Overall, this research bridges the gap between classical hydrodynamic theory and modern artificial intelligence techniques, offering a rapid, reliable, and scalable solution for ship resistance prediction that has the potential to significantly enhance early-stage design processes in naval architecture. 71 79 2024/12/32025/02/22025/02/22025/04/92025/05/232025/05/13 1404/2/23 2025/02/112025/05/272025/05/272025/06/172025/07/82025/07/11 1404/4/20 Poorya Khorsandi Poorya Khorsandi Khorramshahr University of Marine Science and Technology ایران pooryakhorsandy7900@gmail.com Ahmad Hajivand Ahmad Hajivand Khorramshahr Univeristy of Marine Science and Technology ایران hajivand@kmsu.ac.ir Ship Resistance Hydrodynamic Parameters Artificial Intelligence Machine Learning Correlation Analysis Ensemble Methods Design Optimization Holtrop, J., and Mennen, G. G. J., (1982), An approximate power prediction method, International Shipbuilding Progress, 29(335), p.166-170.##ITTC, (2017), Practical guidelines for ship resistance tests, International Towing Tank Conference.##Molland, A. F., Turning, S. and Forbes, P., (2010), Principles of Naval Architecture, Society of Naval Architects and Marine Engineers.##Blevins, R. D., (2014), Applied Fluid Dynamics Handbook, Krieger Publishing Company.##Larsson, L., Stern, F. and Visonneau, M. (Eds.), (2014), Numerical ship hydrodynamics: An assessment of the Gothenburg 2010 workshop, Springer.##Panda, J. P., (2021), Machine Learning for Naval Architecture, Ocean and Marine Engineering, arXiv:2109.05574 (CC BY 4.0).##Gerritsma, J., Onnmk, R. and Versluis, A., (1981), Geometry, Resistance and Stability of the Delft Systematic Yacht Hull Series, Delft University of Technology.##Chen, T., and Guestrin, C., (2016), XGBoost: A scalable tree boosting system, Proceedings of the 22nd ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, p.785-794.##Dorogush, A. V., Gulin, A., Kazeev, V. and Prokhorenkova, L., (2018), CatBoost: gradient boosting with categorical features support, arXiv preprint.##Freund, Y., and Schapire, R. E., (1997), A decision-theoretic generalization of on-line learning and an application to boosting, Journal of Computer and System Sciences, 55(1), p.119-139.##Django Software Foundation, (2023), Django: A high-level Python web framework.##Harris, C. R., et al., (2020), Array programming with NumPy, Nature, 585(7825), p.357-362.##McKinney, W., (2010), Data structures for statistical computing in Python, Proceedings of the 9th Python in Science Conference, p.51-56.##Pedregosa, F., et al., (2011), Scikit-learn: Machine learning in Python, Journal of Machine Learning Research, 12, p.2825-2830.##Tukey, J. W., (1977), Exploratory Data Analysis, Addison-Wesley.##Witten, I. H., Frank, E., Hall, M. A. and Pal, C. J., (2016), Data Mining: Practical Machine Learning Tools and Techniques (4th ed.), Morgan Kaufmann.##Pearson, K., (1895), Notes on regression and inheritance in the case of two parents, Proceedings of the Royal Society of London, 58, p.240-242.##Ke, G., Meng, Q., Finley, T., Wang, T., Chen, W., Ma, W., ... and Liu, T. Y., (2017), LightGBM: A highly efficient gradient boosting decision tree, Advances in Neural Information Processing Systems, 30, p.3146-3154.##Breiman, L., (2001), Random forests, Machine Learning, 45(1), p.5-32.##Cortes, C., and Vapnik, V., (1995), Support-vector networks, Machine Learning, 20(3), p.273-297.##Kohavi, R., (1995), A study of cross-validation and bootstrap for accuracy estimation and model selection, Proceedings of the 14th International Joint Conference on Artificial Intelligence, 2(12), p.1137-1143.##Bergstra, J., and Bengio, Y., (2012), Random search for hyper-parameter optimization, Journal of Machine Learning Research, 13(Feb), p.281-305.##Friedman, J. H., (2001), Greedy Function Approximation: A Gradient Boosting Machine, The Annals of Statistics, 29(5), p.1189-1232.##Géron, A., (2019), Hands-On Machine Learning with Scikit-Learn, Keras, and TensorFlow (2nd ed.), O'Reilly Media. ISBN: 978-1492032649.## ##