Numerical Simulation of Full-Scale Ship Self-Propulsion for Japan Bulk Carrier

2021 ◽  
Author(s):  
Jing Xu ◽  
Yujie Zhou ◽  
Jiawei Yu ◽  
Weihua Deng ◽  
Dakui Feng
Keyword(s):  
Open Water ◽  
Resistance Coefficient ◽  
Full Scale ◽  
The Body ◽  
The Self ◽  
Bulk Carrier ◽  
Prediction Ability ◽  
Blade Element Theory ◽  
Speed Controller ◽  
Friction Line

Abstract The self-propulsion simulations of JBC (Japan Bulk Carrier) were performed in model and full scale with two approach: one is the body force method using steady blade element theory (lift lines theory) and infinite blade propeller, the other is 3-D discretized propeller method. All simulations were investigated using an in-house CFD code which is based on the finite difference method to discretize the governing equations. A dynamic overset technique was used and any revolutions of the propeller can be achieved in the simulation. In order to obtain the self-propulsion point, a PI speed controller was utilized to adjust the rate of revolutions of the propeller. To obtain self-propulsion factors, resistance and open water tests are also computed. Thrust identity method was used to obtain wake fraction. The full scale total resistance coefficient was obtained according two extrapolation methods: the first is the ITTC 1978 recommended procedure, while the second is the extrapolation method based on Grigson friction line. Wake fraction was revised following ITTC recommended procedures in full scale. All the results of the simulation have a reasonable agreement with experimental results. The computational results presented in this paper also provide evidence to the full scale self-propulsion prediction ability of the in-house code.

A New Method for Scaling Submarine Resistance Model Data

2017 ◽  
Author(s):  
Young T. Shen ◽  
Michael J. Hughes
Keyword(s):  
Frictional Resistance ◽  
Resistance Coefficient ◽  
Full Scale ◽  
The Body ◽  
New Method ◽  
Momentum Thickness ◽  
Residual Resistance ◽  
New Approach ◽  
Model Scale ◽  
Scale Resistance

A new method is presented for obtaining full-scale resistance predictions from model-scale submarine resistance tests. Traditionally, model-scale submarine resistance data is scaled using Froude’s Hypothesis, where the resistance is decomposed into frictional resistance and residual resistance. The frictional resistance is computed from a flat plate friction line formula at both model- and full-scale. The residual resistance coefficient is measured model-scale and is assumed to be independent of Reynolds number. Since the flow is assumed to be turbulent at fullscale, turbulence stimulators are placed at about 5% x/L to trip the flow in the model tests. The parasitic drag from the turbulence stimulators must be measured and subtracted from the model-scale resistance. In the new approach a momentum thickness simulator is used in place of a traditional turbulence stimulator. The purpose of the momentum thickness simulator is to achieve similarity for model-scale and full-scale normalized momentum thickness of the boundary layer at the stern of the vessel as momentum thickness is directly related to ship resistance. The size and location of the momentum thickness simulator is computed to assure the flow is turbulent downstream of the simulator and to produce similar momentum thickness on the body downstream of the simulator. With this approach the total resistance is scaled from model-scale to full-scale without decomposing the resistance into frictional resistance and residual resistance. The parasitic drag is not measured and subtracted, as the additional drag from the momentum simulator is computed to produce the correctly scaled momentum thickness. In the new approach the physics associated with resistance is more clearly expressed and improved accuracy of resistance predictions is expected.

‘A pinch of unseen, unguarded dust’: The World and Self in Thomas Hardy's Poems

2018 ◽  
Vol 8 (1) ◽  
pp. 49-66
Author(s):  
Monika Szuba
Keyword(s):  
The Body ◽  
The Self ◽  
Phenomenological Philosophy ◽  
The Earth ◽  
The World ◽  
The Universe ◽  
Recurrent Theme ◽  
Body Subject

The essay discusses selected poems from Thomas Hardy's vast body of poetry, focusing on representations of the self and the world. Employing Maurice Merleau-Ponty's concepts such as the body-subject, wild being, flesh, and reversibility, the essay offers an analysis of Hardy's poems in the light of phenomenological philosophy. It argues that far from demonstrating ‘cosmic indifference’, Hardy's poetry offers a sympathetic vision of interrelations governing the universe. The attunement with voices of the Earth foregrounded in the poems enables the self's entanglement in the flesh of the world, a chiasmatic intertwining of beings inserted between the leaves of the world. The relation of the self with the world is established through the act of perception, mainly visual and aural, when the body becomes intertwined with the world, thus resulting in a powerful welding. Such moments of vision are brief and elusive, which enhances a sense of transitoriness, and, yet, they are also timeless as the self becomes immersed in the experience. As time is a recurrent theme in Hardy's poetry, this essay discusses it in the context of dwelling, the provisionality of which is demonstrated in the prevalent sense of temporality, marked by seasons and birdsong, which underline the rhythms of the world.

Epilogue

2017 ◽  
Author(s):  
Joshua S. Walden
Keyword(s):  
The Body ◽  
The Self ◽  
The Individual ◽  
Relationship Of ◽  
The Relationship

The book’s epilogue explores the place of musical portraiture in the context of posthumous depictions of the deceased, and in relation to the so-called posthuman condition, which describes contemporary changes in the relationship of the individual with such aspects of life as technology and the body. It first examines Alfred Hitchcock’s Vertigo to view how Bernard Herrmann’s score relates to issues of portraiture and the depiction of the identity of the deceased. It then considers the work of cyborg composer-artist Neil Harbisson, who has aimed, through the use of new capabilities of hybridity between the body and technology, to convey something akin to visual likeness in his series of Sound Portraits. The epilogue shows how an examination of contemporary views of posthumous and posthuman identities helps to illuminate the ways music represents the self throughout the genre of musical portraiture.

scholarly journals CFD Simulation for Estimating Efficiency of PBCF Installed on a 176K Bulk Carrier under Both POW and Self-Propulsion Conditions

Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1192
Author(s):  
Dong-Hyun Kim ◽  
Jong-Chun Park ◽  
Gyu-Mok Jeon ◽  
Myung-Soo Shin
Keyword(s):  
Cfd Simulation ◽  
Open Water ◽  
Navier Stokes ◽  
Water Efficiency ◽  
Ocean Engineering ◽  
Bulk Carrier ◽  
Incompressible Viscous Flow ◽  
Korea Research Institute ◽  
Torque Coefficient ◽  
Viscous Flow Field

In this paper, the efficiency of Propeller Boss Cap Fins (PBCF) installed at the bulk carrier was estimated under both Propeller Open Water (POW) and self-propulsion conditions. For this estimation, virtual model-basin tests (resistance, POW, and self-propulsion tests) were conducted through Computational Fluid Dynamics (CFDs) simulation. In the resistance test, the total resistance and the wake distribution according to ship speed were investigated. In the POW test, changes of thrust, torque coefficient, and open water efficiency on the propeller according to PBCF installation were investigated. Finally, the International Towing Tank Conference (ITTC) 1978 method was used to predict the effect of PBCF installation on self-propulsive coefficient and brake horsepower. For analyzing incompressible viscous flow field, the Reynolds-Averaged Navier–Stokes (RANS) equation with SST k-ω turbulence model was calculated using Star-CCM+ 11.06.010-R8. All simulation results were validated by comparing the results of model tests conducted at the Korea Research Institute of Ships and Ocean Engineering (KRISO). Consequently, for the self-propulsion test with the PBCF, a 1.5% reduction of brake horsepower was estimated in the simulation and a 0.5% reduction of the brake horsepower was estimated in the experiment.

Boundaries Influence on the Flow Field Around an Oscillating Sphere

2013 ◽  
Author(s):  
Domenica Mirauda ◽  
Antonio Volpe Plantamura ◽  
Stefano Malavasi
Keyword(s):  
Free Surface ◽  
Flow Field ◽  
Boundary Conditions ◽  
Damping Ratio ◽  
Water Channel ◽  
Open Water ◽  
Free Surface Flows ◽  
The Body ◽  
Sphere Diameter ◽  
Oscillating Sphere

This work analyzes the effects of the interaction between an oscillating sphere and free surface flows through the reconstruction of the flow field around the body and the analysis of the displacements. The experiments were performed in an open water channel, where the sphere had three different boundary conditions in respect to the flow, defined as h* (the ratio between the distance of the sphere upper surface from the free surface and the sphere diameter). A quasi-symmetric condition at h* = 2, with the sphere equally distant from the free surface and the channel bottom, and two conditions of asymmetric bounded flow, one with the sphere located at a distance of 0.003m from the bottom at h* = 3.97 and the other with the sphere close to the free surface at h* = 0, were considered. The sphere was free to move in two directions, streamwise (x) and transverse to the flow (y), and was characterized by values of mass ratio, m* = 1.34 (ratio between the system mass and the displaced fluid mass), and damping ratio, ζ = 0.004. The comparison between the results of the analyzed boundary conditions has shown the strong influence of the free surface on the evolution of the vortex structures downstream the obstacle.

Effect of Exposure to Photographs of Thin Models on Self-Consciousness in Female College Students

2000 ◽  
Vol 86 (3_part_2) ◽  
pp. 1149-1154 ◽  
Author(s):  
Brandy S. Wegner ◽  
Anita M. Hartmann ◽  
C. R. Geist
Keyword(s):  
College Students ◽  
College Women ◽  
Print Media ◽  
The Body ◽  
The Self ◽  
Female College Students ◽  
Female College ◽  
Body Self

The purpose of this study was to assess the immediate influence of brief exposure to images taken from print media on the general self-consciousness and body self-consciousness of 67 college women. After viewing photographs of either thin female models or control photographs, the women completed the Self-consciousness Scale and the Body Self-consciousness Questionnaire. Although a was .45, the college women who looked at images of thin female models gave immediate ratings significantly ( p < .001) higher on both general Self-consciousness and Body Self-consciousness than those who looked at control images.

The Spiritualization of Politics and the Technologies of Resistant Body

2021 ◽  
Vol 17 (2) ◽  
pp. 193-211
Author(s):  
Ashjan Ajour
Keyword(s):  
The Body ◽  
The Self ◽  
Political Prisoners ◽  
Decisive Factor ◽  
Political Strategy ◽  
Colonial Power ◽  
Hunger Strike ◽  
Technologies Of The Self ◽  
Principal Tool ◽  
A Site

Abstract This article explores the body as a site of subjectivity production during a hunger strike in Occupied Palestine. It further explores the former political prisoners’ theory of subjectivity as it emerges through their praxis and philosophy of freedom. Although the body is the principal tool that the hunger strikers use, they don't consider it the decisive factor in attaining their goal. For that they build on the immaterial strength that develops with the deterioration of the body and from which they construct the concept of rouh (soul). This is expressed through the formation of contradictory binaries: body versus soul and body versus mind. The article shows that the hunger strike not only is a political strategy for liberation; it also moves into a spiritualization of the struggle. It uses and problematizes Foucault's “technologies of the self” to theorize the specific formation of subjectivity in the Palestinian hunger strike under colonial conditions, and it contributes to theories of subjectivation. The hunger strikers, in their interaction with the dispossession of the colonial power, invent technologies of resistance to transcend the colonial and carceral constraints on their freedom and create the capacity for the transformation from a submissive subject to a resistant one.

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