• 한국전산유체공학회:학술대회논문집
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• 2001.05a
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• pp.66-71
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• 2001

본 논문은 삼동선의 선형특성에 대한 간략한 소개와 삼동선의 주선체 좌우에 설치되는 보조 선체의 위치가 조파저항성능에 미치는 영향과 그 최적위치선정을 위한 연구 결과를 보인다. 조파저항 계산기법을 이용하여 보조선체의 길이방향과 횡방향의 위치 변화에 대한 조파저항을 계산하였으며, 그 유용성을 검증하기 위하여 모형시험결과와 함께 비교하였다 본 연구를 통하여 보조선체의 횡방향 위치가 삼동선의 조파저항성능에 미치는 영향은 작으나, 길이방향 위치는 그 성능에 커다란 영향을 미치는 것으로 나타났다. 그리고 주선체의 선수부에서 발생된 커다란 파도의 파저에 보조선체의 선수가 놓이는 것이 저항성능에 가장 유리하며, 선속이 빨라짐에 따라서 그 최적위치는 선미쪽으로 옮겨가는 경향을 보였다.

• Journal of the Society of Naval Architects of Korea
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• v.37 no.4
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• pp.11-18
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• 2000

This paper is concerned with the generation of an optimal forward hull form by a nonlinear programming method. A Rankine source panel method based on the inviscid and potential flow approximation is employed to calculate the wave-making resistance and SQP method is also used for the optimization. The hull form is represented by a spline function. The forward hull form of a minimum wave resistance with the given design constraints is generated. In addition, the forward hull form of a minimum total resistance by considering the frictional resistance together with an empirical form factor is produced and compared with the former result.

• Bulletin of the Society of Naval Architects of Korea
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• v.25 no.4
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• pp.28-38
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• 1988

This paper describes the statistical analysis method of predicting the ship resistance. The equation for the wavemaking resistance coefficient is derived as the principal dimensions and sectional area coefficients by using the wavemaking resistance theory and its regression coefficients are determined from the regression analysis of the resistance test results. The equation for the form factor is derived by purely regression analysis of the principal dimensions, sectional area coefficients and resistance test results. Also, it is shown that the wavemaking resistance can be minimize by varying the sectional area curve without changing the principal dimensions of the ship. This methods were applied to the resistance prediction of a bulk carrier. And the, the modified hull form with minimum wavemaking resistance was obtained and the reduction of effective power was confirmed by the resistance test.

• Journal of Korea Ship Safrty Technology Authority
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• v.6
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• pp.76-84
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• 2001

수중익선과 같은 고속선의 경우 수중익이 수면근처에 접근하면 여러형태의 파를 유기하게 되며 그에 의한 압력의 변화를 유발시킨다. 이에따라 양력이 감소하고 조파저항이 증가하다가 한계 Froude 수에 이르게 되면 파가 더이상 자신의 형태를 유지하지 못하고 부서지는 쇄파가 발생하면서 조파저항은 감소하고 그대신 쇄파저항이 급격히 증가하게 된다. 이에대한 연구의 한 방법으로 수면하에서 정속으로 움직이는 수중익에 의하여 생성되는 정상파 및 쇄파현상에 대한 연구를 회류수조에서 수행하였다.

• Journal of Korea Ship Safrty Technology Authority
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• v.18
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• pp.26-38
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• 2005

본 논문에서는 KRISO에서 개발한 선형설계 전용 프로그램인 HCAD와 조파저항 계산 프로그램인 WAVIS를 사용하여 소형 어선을 개발한 예를 보이고 있다. 소형 고속 어선으로 사용되고 있는 차인형 선형을 기준선으로 하여 둥근바닥 선형(Round Bilge Hull Form)을 설계한 과정과, 두 가지 선형에 대한 저항 특성을 이용하여 선체 주위의 유동장과 조파저항을 계산 하였다. 차인형 선형의 저항 특성이 둥근 바닥 선형에 비해 다소 크게 나타났으나 소형 조선소의 건조비를 감안하여 차인형 선형에 대한 저항 감소를 시도하였다. 차인형 선형은 최근 어선의 고속화에 따라 고속 운항시 과도한 선수파가 발생하기 쉽고, 심한 트림이 발생할 가능성이 있으므로, 이러한 문제를 해결하기 위해 선미웨지를 설계하였으며, WAVIS를 이용한 수치계산에 의해 저항 성능이 개선되었음을 확인하였다.

• Journal of the Society of Naval Architects of Korea
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• v.28 no.2
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• pp.28-39
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• 1991

A study on the optimization problems to find forebode shapes with minimum wavemaking and frictional resistance was performed. The afterbody was fixed as a given hull and only forebode offsets were treated as design variables. Design variables were divided into the offsets of given hull and small variation from them. For the wavemaking resistance calculation, Neumann-Kelvin theory was applied to the given hull and thin ship theory was applied to the small variation. ITTC 1957 model-ship correlation line was used for the calculation of frictional resistance. Hull surface was represented mathmatically using shape function. As object function, such as wavemaking and frictional rersistance, was quadratic form of offsets and constraints linear, quadratic programing problem could be constructed. The complementary pivot method was used to find the soulution of the quadratic programing problem. Calculations were perfomed for the Series 60 $C_{B}$=0.6. at Fn=0.289. A realistic hull form could be obtained by using proper constraints. From the results of calculation for the Series 60 $C_{B}$=0.6, it was concluded that present method gave optimal shape of bulbous bow showing a slight improvement in the wave resistance performance at design speed Fn=0.289 compared with the results from the ship theory only.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.758-759
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• 2010

In this study, it was experimentally confirmed that the phenomenon of resonance effect of wave drag in two wavy walls. The channel had saw-tooth type of relief surfaces when supersonic gas flows into this channel. Experiment was carried out on the differential apparatus by conducting the comparative test of two nozzles (round sonic nozzle and two-dimensional nozzle with wavy walls). The two-dimensional nozzle was joined alternately with flat walls which had saw-tooth type of symmetrical and asymmetric reliefs. Two-dimensional nozzle was designed for the M=3 and profiled parabolic contour.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.1
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• pp.78-84
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• 2013

The primary objective of the current work is to develop efficient numerical code to assess the resistance performance of the twin hull form. Resistance performance for the two different twin hull forms with asymmetric and symmetric mono hull using developed code are evaluated. Numerical calculations and model tests have been compared to validate a developed code used in the current work. Comparison were carried out through sinkages of the bow and stern, trim angle and wave-making resistance. Comparative analysis regarding hydrodynamic characteristic of different twin hull forms is worthy of application in the hull form development stage.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.2
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• pp.92-97
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• 2006

Hull forms of a high speed small boat have been developed through numerical studies. A round bilge type hull form has been drived form a using chine hull form with HCAD, a hull form variation software. Wave resistance and the flow fields around the ships have been computed using well-known software, WAVIS. This software employs Rankine source method with non-linear tree surface condition as well as dry transom boundary conditions. The round bilge hull form showed better resistance performance than to the chine hull form for the whole speed range. However, considering the building and labor costs of the small shipyard, the chine hull form has been selected and its wave resistance characteristics has been improved by modifying the bow regions and applying the stem wedge. It is found that the effect of stem wedge is quite satisfactory to improve the resistance characteristics of high speed chine hull form.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.4
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• pp.58-65
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• 1992

In this paper, wave resistance for a submerged body is calculated by a higher order panel method. The Neumann-Kelvin problem is solved by the source or normal dipole distribution method. The body surface is represented by a bicubic B-spline and the singularity strengths are approximated by a bilinear form. The results calculated by the higher order panel method are compared with those by the lowest order panel method developed by Hess & Smith. The convergence rate of the higher order panel method is much better than the lowest order panel method. But the wave resistance calculated by the higher order panel method still shows discrepancy with an analytic solution at low Froude number like that by the lowest order panel method.