Scale Effect of Full Hull Forms with Various Stern Shapes

Yokoo, Koichi; Takahashi, Hajime; Kawakami, Yasuto

doi:10.2534/jjasnaoe1968.1970.128_a51

Cited by 2 publications

(1 citation statement)

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“…The coefficients an of the mapping function (3) are determined from (x, y) coordinates on the body surface to satisfy the above equality constraints ( 1) and (2). On the other hand, an external penalty technique was adopted in order The external penalty technique is a method, in which sum of the obj ective function and a penalty function is minimized, instead of the objective function alone, and in order to avoid searching the minimum value out of the range allowed by the constraints, the value of the penalty function increases rapidly if the constraints are violated.…”

Section: Minimization Of Viscous Resistancementioning

confidence: 99%

Study on the Minimization of Ship Viscous Resistance

Nagamatsu

Sakamoto

Baba

1983

J. SNAJ, Nihon zousen gakkai ronbunshu

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The present paper describes an attempt to minimize the viscous resistance of two-dimensional bodies and three-dimensional full form ships under certain design constraints.The minimization was made by means of Hooke and Jeeves' direct search method with an external penalty function. Frictional and viscous pressure resistances are calculated by integrating shear stress and pressure over the hull surface, respectively, which are obtained by the boundary layer calculations based on a higher order theory. In the case of two-dimensional bodies, the boundary layer calculations were made assuming that the boundary layer is laminar from the leading edge to the transition point and is fully turbulent downstream of the transition point. On the other hand, in the case of ship hulls the turbulent boundary layer calculations were started near the fore end.Optimum shapes were determined first for two-dimensional symmetric bodies. The optimum shapes obtained at Reynolds number of 106 and 107 are similar to a conventional wing section and a laminar wing section, respectively. Next, the optimum stern forms for conventional ship form were determined by the same manner.

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Section: Minimization Of Viscous Resistancementioning

confidence: 99%