Статті в журналах: "Wave added resistance"

1

Kashiwagi, Masashi. "Hydrodynamic Study on Added Resistance Using Unsteady Wave Analysis." Journal of Ship Research 57, no. 04 (December 1, 2013): 220–40. http://dx.doi.org/10.5957/jsr.2013.57.4.220.

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It is known that the added resistance in waves can be computed from ship-generated unsteady waves through the unsteady wave analysis method. To investigate the effects of nonlinear ship-generated unsteady waves and bluntness of the ship geometry on the added resistance, measurements of unsteady waves, wave-induced ship motions, and added resistance were carried out using two different (blunt and slender) modified Wigley models. The ship-generated unsteady waves are also produced by the linear superposition using the waves measured for the diffraction and radiation problems and the complex amplitudes of ship motions measured for the motion-free problem in waves. Then a comparison is made among the values of the added resistance by the direct measurement using a dynamometer and by the wave analysis method using the Fourier transform of measured and superposed waves. It is found that near the peak of the added resistance where ship motions become large, the degree of nonlinearity in the unsteady wave becomes prominent, especially at the forefront part of the wave. Thus, the added resistance evaluated with measured waves at larger amplitudes of incident wave becomes much smaller than the values by the direct measurement and by the wave analysis with superposed waves or measured waves at smaller amplitude of incident wave. Discussion is also made on the characteristics of the added resistance in the range of short incident waves.

2

Kim, Yonghwan, Dong-Min Park, Jae-Hoon Lee, Jaehoon Lee, Byung-Soo Kim, Kyung-Kyu Yang, Semyun Oh, and Dong-Yeon Lee. "Numerical Analysis and Experimental Validation of Added Resistance on Ship in Waves." Journal of Ship Research 63, no. 4 (December 1, 2019): 268–82. http://dx.doi.org/10.5957/josr.10180091.

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In this study, the added resistance of a liquefied natural gas carrier (LNGC) in the presence of waves is studied experimentally and numerically.The ship model is an LNGC designed by Samsung Heavy Industries (SHI). Experiments on ship motion responses and added resistance under head sea conditions were conducted at the Seoul National University and SHI. The influences of the experimental methods (captive and self-propulsion methods), incident wave amplitude, and regular and irregular wave conditions on the added resistance are evaluated using the same model ship set at different scales. In the numerical studies, the motion responses and added resistance are obtained using three methods—the strip method by adopting momentum conservation; Rankine panel method using pressure integration; and computational fluid dynamics method, using the difference in the resistances in waves and calm water. The experimental and numerical results under various conditions are compared, and the characteristics of the experimental and numerical results are discussed.

3

Grin, Rob. "On the Prediction of Wave-added Resistance with Empirical Methods." Journal of Ship Production and Design 31, no. 03 (August 1, 2015): 181–91. http://dx.doi.org/10.5957/jspd.2015.31.3.181.

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There is continuous research on analytical, numerical, and (semi)empirical methods to predict wave-added resistance. Most of this research focuses on a particular area, like motion-induced wave added resistance, wave-added resistance in short waves, or is limited to head seas only. The practical application of most methods is therefore often limited. Moreover, most methods require detailed information on hull lines and results are rather sensitive to the discretization of those hull lines. Since 2006, MARIN has been investigating the feasibility of empirical methods that do not have those limitations. They only require the main particulars to predict wave-added resistance. Within the Sea Trial Analysis Joint Industry Project (STA-JIP), a method was developed for the correction of wave-added resistance in head seas covering both the motion-induced and the wave reflection-induced component. This method was further refined and extended to all wave directions within the service performance analysis JIP (SPA-JIP) in 2008. This article presents the results of the comparison between the prediction methods and model tests for almost 50 different ships, comprising more than 1500 tests in regular and irregular seas.

4

Sun, Tao, Ming Hui Yuan, Wei Wang, and Nan Ye. "Study of Wave Added Resistance on Wigley Ship." Applied Mechanics and Materials 468 (November 2013): 105–9. http://dx.doi.org/10.4028/www.scientific.net/amm.468.105.

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Global warming is becoming a serious problem nowadays. The emissions of greenhouse gas from vessels draw great attentions. As a significant research part of vessel seakeeping performance, resistance capability exert pretty effect on energy consuming. A Wigley ship model is set as the object to compute constraint and free model in calm water and head waves on resistance and hydrodynamic potential coefficients by STAR-CCM. Differences are discussed between both models. Effects on calculation of hydrostatic resistance ignoring trim and heave are revealed .Wave added resistance of free model is computed and compared at different amplitudes and wavelengths. How trim and heave matter the computed results are discussed. So does how wavelength and amplitudes influence total resistance is considered.

5

Chen, Shuling, Beilei Zou, Changzhi Han, and Shiqiang Yan. "Comparative Study on Added Resistance and Seakeeping Performance of X-Bow and Wave-Piercing Monohull in Regular Head Waves." Journal of Marine Science and Engineering 10, no. 6 (June 14, 2022): 813. http://dx.doi.org/10.3390/jmse10060813.

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Bow shape has been recognized as an important factor influencing the seakeeping performance and added resistance of ships. This paper presents a numerical comparative study on added resistance and seakeeping of model ships with ‘X-bow’ and a wave-piercing monohull in regular head waves using a computational fluid dynamics (CFD) software. Different wave heights, wavelengths and forward speeds are considered in the systematic investigation in order to characterize the added resistance and wave-induced motions, and to explore the local wave patterns. The results show a considerably different hydrodynamic characteristic by different bow shapes.

6

Gao, Qingze, Lifei Song, and Jianxi Yao. "RANS Prediction of Wave-Induced Ship Motions, and Steady Wave Forces and Moments in Regular Waves." Journal of Marine Science and Engineering 9, no. 12 (December 20, 2021): 1459. http://dx.doi.org/10.3390/jmse9121459.

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The wave-induced motions, and steady wave forces and moments for the oil tanker KVLCC2 in regular head and oblique waves are numerically predicted by using the expanded RANS solver based on OpenFOAM. New modules of wave boundary condition are programed into OpenFOAM for this purpose. In the present consideration, the steady wave forces and moments include not only the contribution of hydrodynamic effects but also the contribution of the inertial effects due to wave-induced ship motions. The computed results show that the contribution of the inertial effects due to heave and pitch in head waves is non-negligible when wave-induced motions are of large amplitude, for example, in long waves. The influence of wave amplitude on added resistance in head waves is also analyzed. The dimensionless added resistance becomes smaller with the increasing wave amplitude, indicating that added resistance is not proportional to the square of wave amplitude. However, wave amplitude seems not to affect the heave and pitch RAOs significantly. The steady wave surge force, sway force and yaw moment for the KVLCC2 with zero speed in oblique waves are computed as well. The present RANS results are compared with available experimental data, and very good agreements are found between them.

7

Hirayama, Tsugukiyo, Kouichi Kayajima, Yong-Ho Choi, and Xuefeng Wang. "Probability Density Distribution of Mean Added Wave Resistance." Journal of the Society of Naval Architects of Japan 1999, no. 186 (1999): 125–34. http://dx.doi.org/10.2534/jjasnaoe1968.1999.186_125.

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8

Cepowski, Tomasz. "Approximating the Added Resistance Coefficient for a Bulk Carrier Sailing in Head Sea Conditions Based on its Geometrical Parameters and Speed." Polish Maritime Research 23, no. 4 (December 1, 2016): 8–15. http://dx.doi.org/10.1515/pomr-2016-0066.

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AbstractThe article presents the mathematical function to calculate the added wave resistance transfer function for bulk carriers. Based on this function, the statistical mean added wave resistance generated by an irregular head wave with arbitrary statistical parameters can be forecasted. The input parameters are: waterplane area, waterplane coefficient, ship speed, and frequency of the regular wave. The model has been developed based on the theory of artificial neural networks. The presented function can be used in design analyses, and for planning shipping routes in situations when basic geometrical parameters of the hull are only available and not the full technical documentation. The article presents sample cases of use of this function to calculate the added wave resistance transfer function and the statistical mean added wave resistance. Another presented application refers to waterplane coefficient optimisation taking into account the added wave resistance at the stage of preliminary bulk carrier design.

9

Yasukawa, Hironori, Akinori Matsumoto, and Shuji Ikezoe. "Wave Height Effect on Added Resistance of Full Hull Ships in Waves." Journal of the Japan Society of Naval Architects and Ocean Engineers 23 (2016): 45–54. http://dx.doi.org/10.2534/jjasnaoe.23.45.

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10

Kashiwagi, Masashi. "Hydrodynamic Study on Added Resistance Using Unsteady Wave Analysis*." Journal of Ship Research 57, no. 4 (December 1, 2013): 220–40. http://dx.doi.org/10.5957/josr.57.4.130036.

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11

Campos, Marcos de Parahyba, and Tsugukiyo Hirayama. "Keel Influence on the Added Wave Resistance for Yachts." Journal of the Society of Naval Architects of Japan 1999, no. 186 (1999): 115–23. http://dx.doi.org/10.2534/jjasnaoe1968.1999.186_115.

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12

Martić, Ivana, Nastia Degiuli, Dubravko Majetić, and Andrea Farkas. "Artificial Neural Network Model for the Evaluation of Added Resistance of Container Ships in Head Waves." Journal of Marine Science and Engineering 9, no. 8 (July 30, 2021): 826. http://dx.doi.org/10.3390/jmse9080826.

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The decrease in ship added resistance in waves fits into both the technical and operational measures proposed by the IMO to reduce the emissions of harmful gases from ships. Namely, the added resistance in waves causes an increase in fuel consumption and the emission of harmful gases in order for the ship to maintain the design speed, especially in more severe sea states. For this reason, it is very important to estimate the added resistance in waves with sufficient accuracy in the preliminary design phase. In this paper, the possibility of applying an ANN to evaluate added resistance in waves at the different sea states that the ship will encounter during navigation is investigated. A numerical model, based on the results of hydrodynamic calculations in head waves, and ANN is developed. The model can estimate the added resistance of container ships with sufficient accuracy, based on the ship characteristics, sailing speed, and the sea state using two wave energy spectra.

13

Wu, Ping-Chen, Md Alfaz Hossain, Naoki Kawakami, Kento Tamaki, Htike Aung Kyaw, Ayaka Matsumoto, and Yasuyuki Toda. "EFD and CFD Study of Forces, Ship Motions, and Flow Field for KRISO Container Ship Model in Waves." Journal of Ship Research 64, no. 01 (March 1, 2020): 61–80. http://dx.doi.org/10.5957/jsr.2020.64.1.61.

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Ship motion responses and added resistance in waves have been predicted by a wide variety of computational tools. However, validation of the computational flow field still remains a challenge. In the previous study, the flow field around the Korea Research Institute for Ships and Ocean Engineering (KRISO) Very Large Crude-oil Carrier 2 tanker model with and without propeller condition and without rudder condition was measured by the authors, as well as the resistance and self-propulsion tests in waves. In this study, the KRISO container ship model appended with a rudder was used for the higher Froude number .26 and smaller block coefficient .65. The experiments were conducted in the Osaka University towing tank using a 3.2-m-long ship model for resistance and self-propulsion tests in waves. Viscous flow simulation was performed by using CFDShip-Iowa. The wave conditions proposed in Computational Fluid Dynamics (CFD) Workshop 2015 were considered, i.e., the wave-ship length ratio λ/L = .65, .85, 1.15, 1.37, 1.95, and calm water. The objective of this study was to validate CFD results by Experimental Fluid Dynamics (EFD) data for ship vertical motions, added resistance, and wake flow field. The detailed flow field for nominal wake and self-propulsion condition will be analyzed for λ/L = .65, 1.15, 1.37, and calm water. Furthermore, bilge vortex movement and boundary layer development on propeller plane, propeller thrust, and wake factor oscillation in waves will be studied.

14

Feng, Yanxin, Ould el Moctar, and Thomas E. Schellin. "Parametric Hull Form Optimization of Containerships for Minimum Resistance in Calm Water and in Waves." Journal of Marine Science and Application 20, no. 4 (December 2021): 670–93. http://dx.doi.org/10.1007/s11804-021-00243-w.

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AbstractThis paper described the process of generating the optimal parametric hull shape with a fully parametric modeling method for three containerships of different sizes. The newly created parametric ship hull was applied to another ship with a similar shape, which greatly saved time cost. A process of selecting design variables was developed, and during this process, the influence of these variables on calm water resistance was analyzed. After we obtained the optimal hulls, the wave added resistance and motions of original hulls and optimal hulls in regular head waves were analyzed and compared with experimental results. Computations of the flow around the hulls were obtained from a validated nonlinear potential flow boundary element method. Using the multi-objective optimization algorithm, surrogate-based global optimization (SBGO) reduced the computational effort. Compared with the original hull, wave resistance of the optimal hulls was significantly reduced for the two larger ships at Froude numbers corresponding to their design speeds. Optimizing the hull of the containerships slightly reduced their wave added resistance and total resistance in regular head waves, while optimization of their hulls hardly affected wave-induced motions.

15

Hengelmolen, Vera, and Peter R. Wellens. "An experimental study on added resistance focused on the effects of bow wave breaking and relative wave measurements." International Shipbuilding Progress 69, no. 1 (June 14, 2022): 61–89. http://dx.doi.org/10.3233/isp-210018.

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The added resistance is a resistance component that is not yet satisfactorily predicted, although its accurate estimation is crucial – both from an environmental and economic point of view – from the design stage of a ship until its operation. One of the possible sources of overprediction is the occurrence of bow wave breaking. The first aim of this paper is to study the effect of bow wave breaking on added resistance by combining visual observations with resistance tests. On the other hand, as the bow region of a ship appears to be the most dominant contributor to added resistance, this paper introduces a dynamic waterline detection method involving stereo vision. This experimental method is applied to reach the second aim of this paper, which is to stress the importance of the relative wave elevation in the bow region of the ship. By placing stereo rigs inside the hull of a semi-transparent ship, the waterline at each momnent in time can be tracked using an edge detection algorithm. By performing resistance tests on the Delft Systematic Deadrise Series ship model no. 523, the added resistance is observed to be proportional to the relative wave height squared. The data of the experiment and the information necessary to reproduce the experiment are shared through https://doi.org/10.4121/19525852.

16

Grin, Rob. "On the Prediction of Wave-added Resistance with Empirical Methods." Journal of Ship Production and Design 31, no. 3 (August 1, 2015): 181–91. http://dx.doi.org/10.5957/jspd.31.3.130060.

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17

Gutiérrez-Romero, José Enrique, and Jerónimo Esteve-Pérez. "Assessment of the Influence of Added Resistance on Ship Pollutant Emissions and Freight Throughput Using High-Fidelity Numerical Tools." Journal of Marine Science and Engineering 10, no. 1 (January 10, 2022): 88. http://dx.doi.org/10.3390/jmse10010088.

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The reduction of ship pollutants is a key issue in the international agenda. Emissions estimation is usually based on standard calculations that consider the different scenarios of ships. This work presents research on the influence of added resistance on ship emissions and freight throughput. First, a methodology to assess the added resistance influence is shown. The procedure is applied to a roll on-roll off ship under two load conditions. Analyses are computed to value wind- and wave-added resistances for different seasons. An investigation on ship pollutant emissions for a whole route is performed. Moreover, the influence of added resistance on the ship freight throughput is analyzed. Finally, some relevant information is concluded. For instance, a difference of up to 53% in pollutant emission estimation is observed if added resistance is considered. Additionally, the navigation in added resistance conditions could lead to a freight loss of 18% per operational year.

18

Hirayama, Tsugukiyo, and Xuefeng Wang. "Simple Estimation of Wave Added Resistance from Experiments in Transient and Irregular Water Waves." Journal of the Society of Naval Architects of Japan 1993, no. 174 (1993): 275–87. http://dx.doi.org/10.2534/jjasnaoe1968.1993.174_275.

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19

Wang, Xujie, Ri Zhang, Jing Zhao, and Pengfei Cao. "Study on Wave Added Resistance of Ships in Oblique Waves Based on Panel Method." Journal of Ocean University of China 21, no. 3 (May 13, 2022): 773–81. http://dx.doi.org/10.1007/s11802-022-5074-3.

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20

Hermans, A. J. "Added Resistance by Means of Time-Domain Models in Seakeeping." Journal of Ship Research 49, no. 04 (December 1, 2005): 252–62. http://dx.doi.org/10.5957/jsr.2005.49.4.252.

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In many applications in seakeeping the added resistance plays an important role. It is observed that many of the existing methods underestimate the added resistance at low wave frequencies. This may be due to the way the potential is split up. It is shown that with the help of the steady wave potential obtained by RAPID, a linearization around the obtained steady free surface is possible and that the results obtained with a time-domain approach fit very well with the experimental results for a liquid natural gas (LNG) carrier obtained at MARIN. Also an asymptotic theory is presented that is able to predict the added resistance at low forward speed with rather simple means. In this case the problem is linearized with respect to the double body potential. Some results are shown for a circular cylinder.

21

Zhang, Wei, and Ould el Moctar. "Numerical prediction of wave added resistance using a Rankine Panel method." Ocean Engineering 178 (April 2019): 66–79. http://dx.doi.org/10.1016/j.oceaneng.2019.02.055.

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22

Lee, Jaehoon, Dong-Min Park, and Yonghwan Kim. "Experimental investigation on the added resistance of modified KVLCC2 hull forms with different bow shapes." Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment 231, no. 2 (April 28, 2016): 395–410. http://dx.doi.org/10.1177/1475090216643981.

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The effect of different bow shapes on the added resistance in waves was observed through a series of model tests. To this end, three different hull forms of KRISO Very Large Crude Carrier 2 were considered: an original hull form and two modified hulls with different bow shapes, called ax-bow and leadge-bow. The model tests were conducted for a wide range of wavelengths with two wave amplitudes in a regular head-sea condition at the design speed. Each test condition was imposed at least twice in order to check the repeatability of measurement, considering the uncertainties in model test and the nonlinear nature of the added resistance. This article introduces a preliminary study on the effects of surge motion, amplitude of incident wave, and green-water allowance around bow region. This article briefly includes the uncertainty analysis of recent study regarding the performance of the original hull. Based on the results of the experimental study for three different bow shapes, the parameters which influence the added resistance and motion responses are discussed.

23

Fang, Ming-Chung, Yi-Chin Wu, Deng-Kai Hu, and Zi-Yi Lee. "The Prediction of the Added Resistance for the Trimaran Ship With Different Side Hull Arrangements in Waves." Journal of Ship Research 53, no. 04 (December 1, 2009): 227–35. http://dx.doi.org/10.5957/jsr.2009.53.4.227.

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In this paper, a second-order steady-state approach and a three-dimensional pulsating source distribution method are applied to derive the added resistance on a trimaran ship advancing in waves. The added resistance treated here is the secondorder steady-state hydrodynamic force, which can be expressed as products of the ship-motion responses, the radiation potential, diffraction potential, and the incident wave potential, and all related velocity potentials are in three-dimensional form. The steady flow potential is also included in the motion response calculation to investigate its effect on the added resistance. In order to validate the prediction method, the experiments for measuring the added resistance of a trimaran model in head waves were also handled in a National Cheng Kung University (NCKU) towing tank, and the related data are adopted to compare with the theoretical results. The comparisons show that the prediction results obtained in the paper generally agree well with experimental data; the validity of the prediction method applied here can be regarded as acceptable, and the effect of the steady flow potential on the added resistance of the trimaran ship can be neglected.

24

Kihara, Hajime, Shigeru Naito, and Makoto Sueyoshi. "Numerical Analysis of the Influence of Above-Water Bow Form on Added Resistance Using Nonlinear Slender Body Theory." Journal of Ship Research 49, no. 03 (September 1, 2005): 191–206. http://dx.doi.org/10.5957/jsr.2005.49.3.191.

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A nonlinear numerical method is presented for the prediction of the hydrodynamic forces that act on an oscillating ship with a forward speed in head waves. A "parabolic" approximation of equations called "2.5D" or "2D+T" theory was used in a three-dimensional ship wave problem, and the computation was carried out in the time domain. The nonlinear properties associated with the hydrostatic, hydrodynamic, and Froude-Krylov forces were taken into account in the framework of the slender body theory. This work is an extension of the previous work of Kihara and Naito (1998). The application of this approach to the unsteady wave-making problem of a ship with a real hull form is described. The focus is on the influence of the above-water hull form on the horizontal mean wave force. Comparison with experimental results demonstrates that the method is valid in predicting added resistance. Prediction of added resistance for blunt ships is also shown by example.

25

Moonesun, Mohammad, Mehran Javadi, Seyyed Hossein Mousavizadegan, Hosein Dalayeli, Yuri Mikhailovich Korol, and Ataollah Gharachahi. "Computational fluid dynamics analysis on the added resistance of submarine due to Deck wetness at surface condition." Proceedings of the Institution of Mechanical Engineers, Part M: Journal of Engineering for the Maritime Environment 231, no. 1 (August 3, 2016): 128–36. http://dx.doi.org/10.1177/1475090215626462.

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This article describes the evaluation of the wave profile of submarine at surface condition and deck flooding which occurred by the wave making pattern at the bow. Movement of ships and submarines on the free surface of calm water creates the surface wave. Because of the difference in the bow shape and freeboard height, the wave making system in ships and submarines is different. Rounded or elliptical bow shape of submarines generates a high bow wave which causes deck and bow wetness. This is because of the fact that in submarines, this situation arises a small freeboard. In submarines, Deck wetness (because of deck flooding) is a very important subject that has some remarkable consequences, such as increase in resistance and added weigh. The focus of this article is on the added frictional resistance in the deck wetness condition. The bow wave profile, deck wetness and added resistance are studied in several Froude numbers by computational fluid dynamics method. This analysis is performed for a bare hull model at two different drafts by Flow Vision (V.2.3) software based on computational fluid dynamics method and solving the Reynolds-averaged Navier–Stokes equations.

26

Kara, Fuat. "Time Domain Prediction of Added Resistance of Ships." Journal of Ship Research 55, no. 03 (September 1, 2011): 163–84. http://dx.doi.org/10.5957/jsr.2011.55.3.163.

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The prediction of the added resistance of the ships that can be computed from quadratic product of the first-order quantities is presented using the near-field method based on the direct pressure integration over floating body in time domain. The transient wave-body interaction of the first-order radiation and diffraction problems are solved as the impulsive velocity of the floating body by the use of a three dimensional panel method with Neumann-Kelvin method. These radiation and diffraction forces are the input for the solution of the equation of the motion that is solved by the use of the time marching scheme. The exact initial-boundary-value problem is linearized about a uniform flow, and recast as an integral equation using the transient free-surface Green function. A Wigley III hull form with forward speed is used for the numerical prediction of the different parameters. The calculated mean second-order added resistance and unsteady first-order impulse-response functions, hydrodynamics coefficients, exciting forces, and response amplitude operators are compared with experimental results.

27

Fonteinos, Michael I., Efstratios I. Tzanos, and Nikolaos P. Kyrtatos. "Ship Hull Fouling Estimation Using Shipboard Measurements, Models for Resistance Components, and Shaft Torque Calculation Using Engine Model." Journal of Ship Research 61, no. 02 (June 1, 2017): 64–74. http://dx.doi.org/10.5957/jsr.2017.61.2.64.

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This paper presents a method for hull condition estimation regarding fouling, by focusing on the increase of power demand over a period. Onboard recorded data from performance reports and noon reports of four Panamax bulk carriers identical sister ships were provided by a shipping company. In most cases, engine power onboard vessels is measured using a torque meter. Since torque measurements are generally considered of variable reliability and the required accuracy for the present study was high, the propeller shaft torque demand was calculated using an engine simulation software tuned for each specific engine and fed with recorded engine data. To distinguish the effect of fouling, wave-added resistance, air resistance, and calm water resistance were deducted from total ship resistance. Wave-added and air resistances were calculated using the STAwave-2 empirical method and Fujiwara regression formula, respectively. Calm water resistance was calculated using the FORMDATA systematic statistical series due to the lack of vessel's lines. The increase of resistance due to fouling was estimated through the increase of the Propeller Law coefficient (CPROP) and the Fouling Resistance coefficient (CFOUL), over a dry dock interval period.

28

Yang, Kyung-Kyu, Beom-Soo Kim, Yonghwan Kim, Masashi Kashiwagi, and Hidetsugu Iwashita. "Numerical Study on Unsteady Pressure Distribution on Bulk Carrier in Head Waves with Forward Speed." Processes 9, no. 1 (January 18, 2021): 171. http://dx.doi.org/10.3390/pr9010171.

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This study deals with wave-induced unsteady pressure on a ship moving with a constant forward speed in regular head waves. Two different numerical methods are applied to solve wave–ship interaction problems: a Rankine panel method which adopts velocity potential, and a Cartesian-grid method which solves the momentum and mass conservation equations under the assumption of inviscid and incompressible fluids. Before comparing l1ocal pressure distributions, the computational methods are validated for global quantities, such as ship motion responses and added resistance, by comparison with available experimental data. Then, the computational results and experimental data are compared for hydrodynamic pressure, particularly focusing on the magnitude of the first-harmonic component in different sections and vertical locations. Furthermore, the Cartesian-grid method is used to simulate the various wave-amplitude conditions, and the characteristics of the zeroth-, first-, and second-harmonic components of wave-induced pressure are investigated. The nonlinearity of pressure distribution is observed mostly from the pressure near the still-water-level of the ship bow and the normalized first-harmonic component of wave-induced pressure decreases as the wave steepness increases. Lastly, to understand the local characteristics of wave-induced unsteady pressure, the time-averaged added pressure and added local force are analyzed. It is found that the major contribution of the time-averaged added local force that occurs around the ship stem above the design waterline.

29

Hearn, G. E., K. C. Tong, and S. M. Lau. "Sensitivity of Wave Drift Damping Coefficient Predictions to the Hydrodynamic Analysis Models Used in the Added Resistance Gradient Method." Journal of Offshore Mechanics and Arctic Engineering 110, no. 4 (November 1, 1988): 337–47. http://dx.doi.org/10.1115/1.3257071.

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This paper is concerned with the formulation and simplifications of the general fluid structure interaction analysis for an advancing oscillating vessel in waves to provide alternative 3D hydrodynamic models to determine first and second-order wave-induced fluid loadings, and, hence, the prediction of low-frequency wave damping coefficients. Heuristic arguments which lead to the Added Resistance Gradient (ARG) method of calculating low-frequency damping coefficients together with two 3D-based calculation procedures are presented. Predictions of added resistance and motion responses are compared with other published data. The intermediate hydrodynamic coefficient predictions based on 2D and 3D hydrodynamic models are compared. Low-frequency damping coefficient predictions based on the two proposed 3D calculation procedures are compared with experimental measurements and earlier published generalized strip theory values. Assessment of the applicability of the procedures, the result of their application, and further possible generalizations of the methods are discussed.

30

Dai, Kun, Yunbo Li, Jiaye Gong, Zheng Fu, Ang Li, and Dapeng Zhang. "NUMERICAL STUDY ON PROPULSIVE FACTORS IN REGULAR HEAD AND OBLIQUE WAVES." Brodogradnja 73, no. 1 (January 1, 2022): 37–56. http://dx.doi.org/10.21278/brod73103.

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This paper applies Reynolds-averaged Navier-Stokes (RANS) method to study propulsion performance in head and oblique waves. Finite volume method (FVM) is employed to discretize the governing equations and SST k-ω model is used for modeling the turbulent flow. The free surface is solved by volume of fluid (VOF) method. Sliding mesh technique is used to enable rotation of propeller. Propeller open water curves are determined by propeller open water simulations. Calm water resistance and wave added resistances are obtained from towing computations without propeller. Self-propulsion simulations in calm water and waves with varying loads are performed to obtain self-propulsion point and thrust identify method is use to predict propulsive factors. Regular head waves with wavelengths varying from 0.6 to 1.4 times the length of ship and oblique waves with incident directions varying from 0° to 360° are considered. The influence of waves on propulsive factors, including thrust deduction and wake fraction, open water, relative rotative, hull and propulsive efficiencies are discussed.

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Safari, Ali, and Amir H. Nikseresht. "Numerical investigation of added resistance and wave pattern on a planing vessel in regular head waves." International Journal of Engineering Systems Modelling and Simulation 10, no. 3 (2018): 169. http://dx.doi.org/10.1504/ijesms.2018.094085.

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32

Safari, Ali, and Amir H. Nikseresht. "Numerical investigation of added resistance and wave pattern on a planing vessel in regular head waves." International Journal of Engineering Systems Modelling and Simulation 10, no. 3 (2018): 169. http://dx.doi.org/10.1504/ijesms.2018.10015384.

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33

Chen, Si, Takanori Hino, Ning Ma, and Xiechong Gu. "RANS investigation of influence of wave steepness on ship motions and added resistance in regular waves." Journal of Marine Science and Technology 23, no. 4 (January 12, 2018): 991–1003. http://dx.doi.org/10.1007/s00773-018-0527-5.

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34

Sun, Yu-Hang, and Bao-Ji Zhang. "Seakeeping Design Optimization of KRISO Container Ship (KCS) Ship Form Considering Wave Action." Marine Technology Society Journal 56, no. 2 (April 27, 2022): 64–72. http://dx.doi.org/10.4031/mtsj.56.2.6.

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Abstract Combined with the optimization method, the seakeeping optimization design problem under regular waves is studied on the basis of potential flow theory. The Rankine source method and deep-water Stokes wave theory are used to design the energy-saving ship form in the actual navigation. Taking the bow and stern waterlines of the Korea Institute of Ships and Ocean Engineering container ship as the optimization design area, the free-form deformation method is used to realize the parametric modeling and geometric reconstruction of the hull. Taking the minimum wave added resistance and the minimum sum of heave and pitch amplitude as the objective function, the Sobol algorithm and improved non-dominated sorting genetic algorithm (NSGA-II) are used to optimize the hull design while ensuring the necessary displacement volume. This study confirmed that the seakeeping performance of the optimized ship is the best. The results show that the wave added resistance of the optimized ship is reduced by 6.344%, and the sum of heave and pitch amplitude is reduced by 3.475%. Therefore, the feasibility of the proposed optimization method can be verified.

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Cepowski, Tomasz. "Identification Accuracy of Additional Wave Resistance Through a Comparison of Multiple Regression and Artificial Neural Network Methods." Multidisciplinary Aspects of Production Engineering 1, no. 1 (September 1, 2018): 197–204. http://dx.doi.org/10.2478/mape-2018-0026.

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Abstract The article presents the use of multiple regression method to identify added wave resistance. Added wave resistance was expressed in the form of a four-state nominal function of: “thrust”, “zero”, “minor” and “major” resistance values. Three regression models were developed for this purpose: a regression model with linear variables, nonlinear variables and a large number of nonlinear variables. The nonlinear models were developed using the author's algorithm based on heuristic techniques. The three models were compared with a model based on an artificial neural network. This study shows that non-linear equations developed through a multiple linear regression method using the author’s algorithm are relatively accurate, and in some respects, are more effective than artificial neural networks.

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Kim, Beom-Soo, Min-Jae Oh, Jae-Hoon Lee, Yong-Hwan Kim, and Myung-Il Roh. "Study on Hull Optimization Process Considering Operational Efficiency in Waves." Processes 9, no. 5 (May 19, 2021): 898. http://dx.doi.org/10.3390/pr9050898.

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This study investigates the optimization of the hull form of a tanker, considering the operational efficiency in waves, in accordance with the recent Energy Efficiency Design Index regulation. For this purpose, the total resistance and speed loss of the ship under representative sea conditions were minimized simultaneously. The total resistance was divided into three components: calm water resistance, added resistance due to wind, and to waves. The first two components were calculated using regression formulas, and the last component was estimated using the strip theory, far-field method, and the short-wave correction formula. Next, prismatic coefficient, waterline length, waterplane area, and flare angle were selected as design variables from the perspective of operational efficiency. The hull form was described as a combination of cross-sectional curves. A combination of the method shifting these sections in the longitudinal direction and the Free-Form Deformation method was used to deform the hull. As a result of applying the non-dominated sorting genetic algorithm to a tanker, the hull was deformed thinner and longer, and it was determined that the total resistance and speed loss were reduced by 3.58 and 10.2%, respectively. In particular, the added resistance due to waves decreased significantly compared to the calm water resistance, which implies that the present tendency differs from conventional ship design that optimizes only the calm water resistance.

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Kataoka, Shiro, and Hidetsugu Iwashita. "Estimations of Motions and Added Wave Resistance of Ships Advancing in Waves by a Time-Domain Hybrid Method." Journal of the Japan Society of Naval Architects and Ocean Engineers 2 (2005): 217–28. http://dx.doi.org/10.2534/jjasnaoe.2.217.

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38

Gerritsma, J., and J. A. Keuning. "Performance of Light-and Heavy-Displacement Sailing Yachts in Waves." Marine Technology and SNAME News 26, no. 01 (January 1, 1989): 14–22. http://dx.doi.org/10.5957/mt1.1989.26.1.14.

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Experiments with light-and moderate-displacement sailing yacht models have been carried out in the Delft Ship Hydromechanics Laboratory to investigate heave, pitch, and added resistance in regular waves. The experiments included conditions with and without heel and leeway angles. The results are analyzed and compared with calculations based on a strip theory method. Numerical methods are used to predict and to compare the performance of sailing yachts in realistic irregular-wave conditions.

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Waskito, Kurniawan Teguh, and Yanuar. "On the High-Performance Hydrodynamics Design of a Trimaran Fishing Vessel." Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 83, no. 1 (June 3, 2021): 17–33. http://dx.doi.org/10.37934/arfmts.83.1.1733.

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Trimaran hull form as multihull ship becomes more attractive these days in various ship types. It offers more advantages in terms of seakeeping performances, particularly on the application of a fishing vessel. However, thus far, the conventional design of fishing vessels is not favorable to ensure the safety of a vessel sailing in a rough sea. In conjunction with such issues, we discuss a trimaran fishing vessel design based on the seakeeping criterion to evaluate the dynamic stability, ship motion RAOs, and ship resistances at the initial design stages using linear strip theory. The intact stabilities are calculated to complement the seakeeping results. The analytical method based on the slender body method is used to evaluate the steady wave resistances. The results of heave, pitch, roll motions, and the ship resistances are discussed. At the zero speed and forward speed, the trimaran shows a favorable motion amplitude, although in forward speeds at the case of head seas there is no significant difference. The trimaran presents a favorable steady-resistance up to the ship speed of Fn=0.27, and it becomes deteriorating than the monohull at higher ship speeds. However, the added wave resistances of the wavelength range 1.0 – 3.0 shows significant added resistances at Fn=0.25 and Fn=0.35, respectively. The results of this study present promising seakeeping and resistance characteristics of the trimaran hull form. The trimaran hull form ensures the safety, reliability, and operation efficiency of ships sailing in broader ranges of violent-sea environment.

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Orihara, Hideo. "Comparison of CFD simulations with experimental data for a tanker model advancing in waves." International Journal of Naval Architecture and Ocean Engineering 3, no. 1 (January 1, 2011): 1–8. http://dx.doi.org/10.2478/ijnaoe-2013-0040.

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ABSTRACTIn this paper, CFD simulation results for a tanker model are compared with experimental data over a range of wave conditions to verify a capability to predict the sea-keeping performance of practical hull forms. CFD simulations are conducted using WISDAM-X code which is capable of unsteady RANS calculations in arbitrary wave conditions. Comparisons are made of unsteady surface pressures, added resistance and ship motions in regular waves for cases of fully-loaded and ballast conditions of a large tanker model. It is shown that the simulation results agree fairly well with the experimental data, and that WISDAM-X code can predict sea-keeping performance of practical hull forms.

41

Hirayama, Tsugukiyo, and Marcos de Parahyba Campos. "Improved Measuring Method for Added Wave Resistance of a Yawed and Heeled Sailing Yacht Model." Journal of the Society of Naval Architects of Japan 1998, no. 183 (1998): 101–13. http://dx.doi.org/10.2534/jjasnaoe1968.1998.101.

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42

Choi, Bongjun, Peter R. Wellens, and Rene H. M. Huijsmans. "Experimental assessment of effects of bow-wave breaking on added resistance for the fast ship." International Shipbuilding Progress 66, no. 2 (June 18, 2019): 111–43. http://dx.doi.org/10.3233/isp-180242.

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43

Wang, Xujie, Jing Zhao, Huidong Zhang, Pengfei Cao, and Peng Liu. "Study on Wave Added Resistance of a Deep-V Hybrid Monohull Based on Panel Method." Journal of Ocean University of China 19, no. 3 (May 2, 2020): 601–8. http://dx.doi.org/10.1007/s11802-020-4274-y.

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44

Wang, Wei, Tiecheng Wu, Dagang Zhao, Chunyu Guo, Wanzhen Luo, and Yongjie Pang. "Experimental–numerical analysis of added resistance to container ships under presence of wind–wave loads." PLOS ONE 14, no. 8 (August 20, 2019): e0221453. http://dx.doi.org/10.1371/journal.pone.0221453.

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45

Utina, M. Ridwan. "Kajian Pengaruh Gelombang Irreguler Terhadap Added Resistance pada Kapal Patroli Cepat 36 M." Wave: Jurnal Ilmiah Teknologi Maritim 5, no. 2 (May 17, 2019): 67. http://dx.doi.org/10.29122/jurnalwave.v5i2.3526.

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Salah satu yang menjadi perhatian penting bagi seorang desainer dan operator kapal adalah bagaimana perilaku kapal di laut dalam kaitan dengan kecepatan kapal yang tetap pada kondisi gelombang. Kondisi laut yang bergelombang dapat menyebabkan terjadinya gerakan kapal dan pada gilirannya gerakan kapal akan menimbulkan tahanan tambahan. JIka masih tersedia kelebihan tenaga mesin, kapal dapat berlayar pada kecepatan tetap. Namun, sampai saat ini tahanan tambahan sering digunakan dalam penambahan tenaga mesin antara 15 dan 30 persen dari tahanan pada kondisi air tenang. Evaluasi yang berkaitan dengan tenaga tambahan, yang dapat dipertanggunjawabkan, dapat diperoleh dari uji model atau metode numerik. Tulisan ini mendiskusikan tentang pengaruh gelombang tidak teratur pada tahanan tambahan pada Kapal Patroli Cepat melalui uji model. Keywords : Added Resistance, Engine Power, Irregular Wave.

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Oh, Seunghoon, and Jinho Yang. "A Study on Estimation of Added Resistance in Waves Using Modified Radiated Energy Method and Short Wave Correction Method." Journal of the Society of Naval Architects of Korea 53, no. 1 (February 20, 2016): 62–68. http://dx.doi.org/10.3744/snak.2016.53.1.62.

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47

Le, Trung-Kien, Ngo Van He, Ngo Van Hien, and Ngoc-Tam Bui. "Effects of a Bulbous Bow Shape on Added Resistance Acting on the Hull of a Ship in Regular Head Wave." Journal of Marine Science and Engineering 9, no. 6 (May 21, 2021): 559. http://dx.doi.org/10.3390/jmse9060559.

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In this study, the effect of bow shape on resistance acting on a hull in regular head waves was investigated by applying a commercial Computational Fluid Dynamics (CFD) code. For this purpose, the hydrodynamic performance as well as the resistance of ships with blunt and bulbous bows were simulated. By analyzing the obtained CFD simulation results, the effects of the bow shape on the hydrodynamic performance and resistance of the ships were found. A new bulbous bow shape with drastically reduced added resistance acting on the hull in waves is proposed. Finally, the obtained CFD results for the hydrodynamic performance of ships are presented.

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Seo, Seonguk, Sunho Park, and BonYong Koo. "Effect of wave periods on added resistance and motions of a ship in head sea simulations." Ocean Engineering 137 (June 2017): 309–27. http://dx.doi.org/10.1016/j.oceaneng.2017.04.009.

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49

Pedersen, O. F., T. F. Pedersen, and M. R. Miller. "Gas compression in lungs decreases peak expiratory flow depending on resistance of peak flowmeter." Journal of Applied Physiology 83, no. 5 (November 1, 1997): 1517–21. http://dx.doi.org/10.1152/jappl.1997.83.5.1517.

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Pedersen, O. F., T. F. Pedersen, and M. R. Miller. Gas compression in lungs decreases peak expiratory flow depending on resistance of peak flowmeter. J. Appl. Physiol. 83(5): 1517–1521, 1997.—It has recently been shown (O. F. Pedersen T. R. Rasmussen, Ø. Omland, T. Sigsgaard, P. H. Quanjer, and M. R. Miller. Eur. Respir. J. 9: 828–833, 1996) that the added resistance of a mini-Wright peak flowmeter decreases peak expiratory flow (PEF) by ∼8% compared with PEF measured by a pneumotachograph. To explore the reason for this, 10 healthy men (mean age 43 yr, range 33–58 yr) were examined in a body plethysmograph with facilities to measure mouth flow vs. expired volume as well as the change in thoracic gas volume (Vb) and alveolar pressure (Pa). The subjects performed forced vital capacity maneuvers through orifices of different sizes and also a mini-Wright peak flowmeter. PEF with the meter and other added resistances were achieved when flow reached the perimeter of the flow-Vb curves. The mini-Wright PEF meter decreased PEF from 11.4 ± 1.5 to 10.3 ± 1.4 (SD) l/s ( P < 0.001), Pa increased from 6.7 ± 1.9 to 9.3 ± 2.7 kPa ( P < 0.001), an increase equal to the pressure drop across the meter, and caused Vb at PEF to decrease by 0.24 ± 0.09 liter ( P < 0.001). We conclude that PEF obtained with an added resistance like a mini-Wright PEF meter is a wave-speed-determined maximal flow, but the added resistance causes gas compression because of increased Pa at PEF. Therefore, Vb at PEF and, accordingly, PEF decrease.

50

Han, S. "Finite volume solution of 2-D hyperbolic conduction with contact resistance." International Journal of Numerical Methods for Heat & Fluid Flow 27, no. 9 (September 4, 2017): 2154–72. http://dx.doi.org/10.1108/hff-08-2016-0319.

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Purpose The purpose of this paper is to present a numerical methodology for the solution of non-Fourier conduction in two-dimensional (2-D) heterogeneous materials with contact resistance. Design/methodology/approach Energy and heat flux equations with time lagging constant are combined to form a 2-D hyperbolic conduction equation in conservational form, and the resulting equation is solved by finite volume method. Findings The magnitude of contact resistance is inversely proportional to the temperature jump at the contact surface and phonon transmission coefficient between heterogeneous medium. Numerical results show that higher the contact resistance, lower the heat flux through the interface, lower the strength of transmitted wave and higher the strength of reflected wave at the interface. These results are in agreement with physical expectations. Temperature profiles show expected discontinuity at the interface while the heat fluxes are continuous, demonstrating the accuracy of the proposed methodology. Originality/value In most available numerical methods for hyperbolic conduction with contact resistance, contact resistances are treated as internal boundaries at which boundary conditions are specified. In the present formulation, contact resistance between two heterogeneous materials is treated as a part of interface transport properties not as an added boundary condition. This approach makes the formulation much simpler and straightforward for multidimensional applications. This approach is never used previously and is original.

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