Quarterly Journal of Mechanics and Applied Mathematics最新文献_第9页

Diffraction by an impedance strip II. Solving Riemann-Hilbert problems by OE-equation method 阻抗条衍射II。用e -方程方法求解Riemann-Hilbert问题

IF 0.9 4区工程技术

Quarterly Journal of Mechanics and Applied Mathematics Pub Date : 2014-12-01 DOI: 10.1093/qjmam/hbv011

A. Shanin, A. I. Korolkov

引用次数: 3

Diffraction by an impedance strip I. Reducing diffraction problem to Riemann-Hilbert problems 阻抗条衍射1 .将衍射问题化为黎曼-希尔伯特问题

IF 0.9 4区工程技术

Quarterly Journal of Mechanics and Applied Mathematics Pub Date : 2014-12-01 DOI: 10.1093/qjmam/hbv010

A. Shanin, A. I. Korolkov

引用次数: 5

Free-surface hydrodynamics of a submerged prolate spheroid in finite water depth based on the method of multipole expansions 基于多极展开法的有限水深下淹没长形球体的自由表面流体力学

IF 0.9 4区工程技术

Quarterly Journal of Mechanics and Applied Mathematics Pub Date : 2014-11-01 DOI: 10.1093/QJMAM/HBU016

I. Chatjigeorgiou, T. Miloh

{"title":"Free-surface hydrodynamics of a submerged prolate spheroid in finite water depth based on the method of multipole expansions","authors":"I. Chatjigeorgiou, T. Miloh","doi":"10.1093/QJMAM/HBU016","DOIUrl":"https://doi.org/10.1093/QJMAM/HBU016","url":null,"abstract":"Summary Free-surface hydrodynamics of a submerged elongated (prolate) spheroid in water of finite depth is considered by employing spheroidal harmonics and the method of multipole expansions. In particular, we present semi-analytic solutions for both the wave making resistance and wave diffraction fundamental problems. Although these two cases are generally treated separately, it is demonstrated here that by using the present general methodology, the analytic procedures of these two problems are quite similar and thus the corresponding solutions can be obtained by using almost a single effort. The motion of the prolate spheroid is rectilinear and steady in a direction parallel to the undisturbed free surface and rigid planar bottom. The ambient wave field is assumed to be monochromatic with an arbitrary inclination angle with respect to the body’s major axis. The Green’s function based solution, employs Havelock’s formula for the ultimate image singularity system which avoids redundant surface integrations and solving integral equations. Numerical simulations of the linearized Kelvin-Neumann problem for the hydrodynamic forces and moments exerted on the moving spheroid for different depths of submergence and flow parameters are presented and compared against the existing data, given mainly for spherical shapes. The present method is claimed to be simpler to implement and more versatile, yet more accurate with respect to existing codes. Aside from free surface hydrodynamics, it can be also extended to other harmonic practical problems involving interacting ellipsoidal geometries in confined domain.","PeriodicalId":56087,"journal":{"name":"Quarterly Journal of Mechanics and Applied Mathematics","volume":"67 1","pages":"525-552"},"PeriodicalIF":0.9,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/QJMAM/HBU016","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61239392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13

The use of helical coordinate systems 螺旋坐标系的使用

IF 0.9 4区工程技术

Quarterly Journal of Mechanics and Applied Mathematics Pub Date : 2014-11-01 DOI: 10.1093/QJMAM/HBU017

E. Vachagina, A. Kadyirov

引用次数: 11

The scattering properties of a system of structures in water waves 水波中结构系统的散射特性

IF 0.9 4区工程技术

Quarterly Journal of Mechanics and Applied Mathematics Pub Date : 2014-11-01 DOI: 10.1093/QJMAM/HBU021

M. Mciver

引用次数: 8

On three methods for explicit handling of convolutions as applied to brownian excursions and parisian barrier options 三种显式处理卷积的方法应用于布朗漂移和巴黎势垒选择

IF 0.9 4区工程技术

Quarterly Journal of Mechanics and Applied Mathematics Pub Date : 2014-11-01 DOI: 10.1093/QJMAM/HBU022

M. Schröder

引用次数: 2

Homogenisation for hexagonal lattices and honeycomb structures 六边形晶格和蜂窝结构的均质化

IF 0.9 4区工程技术

Quarterly Journal of Mechanics and Applied Mathematics Pub Date : 2014-11-01 DOI: 10.1093/QJMAM/HBU019

M. Makwana, R. Craster

引用次数: 11

Rivulet flow round a horizontal cylinder subject to a uniform surface shear stress 受均匀表面剪应力作用而绕水平圆柱体流动的小溪

IF 0.9 4区工程技术

Quarterly Journal of Mechanics and Applied Mathematics Pub Date : 2014-11-01 DOI: 10.1093/QJMAM/HBU018

C. Paterson, Stephen K. Wilson, B. Duffy

{"title":"Rivulet flow round a horizontal cylinder subject to a uniform surface shear stress","authors":"C. Paterson, Stephen K. Wilson, B. Duffy","doi":"10.1093/QJMAM/HBU018","DOIUrl":"https://doi.org/10.1093/QJMAM/HBU018","url":null,"abstract":"The steady flow of a slowly varying rivulet with prescribed flux in the azimuthal direction round a large stationary horizontal cylinder subject to a prescribed uniform azimuthal surface shear stress is investigated. In particular, we focus on the case where the volume flux is downwards but the shear stress is upwards, for which there is always a solution corresponding to a rivulet flowing down at least part of one side of the cylinder. We consider both a rivulet with constant non-zero contact angle but slowly varying width (i.e. de-pinned contact lines) and a rivulet with constant width but slowly varying contact angle (i.e. pinned contact lines), and show that they have qualitatively different behaviour. When shear is present, a rivulet with constant non-zero contact angle can never run all the way from the top to the bottom of the cylinder, and so we consider the scenario in which an infinitely wide two-dimensional film of uniform thickness covers part of the upper half of the cylinder and \"breaks\" into a single rivulet with constant non-zero contact angle. In contrast, a sufficiently narrow rivulet with constant width can run all the way from the top to the bottom of the cylinder, whereas a wide rivulet can do so only if its contact lines de-pin, and so we consider the scenario in which the contact lines of a wide rivulet de-pin on the lower half of the cylinder.","PeriodicalId":56087,"journal":{"name":"Quarterly Journal of Mechanics and Applied Mathematics","volume":"37 1","pages":"567-597"},"PeriodicalIF":0.9,"publicationDate":"2014-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/QJMAM/HBU018","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61239447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Freely floating structures trapping time-harmonic water waves 捕获时谐水波的自由浮动结构

IF 0.9 4区工程技术

Quarterly Journal of Mechanics and Applied Mathematics Pub Date : 2014-10-22 DOI: 10.1093/QJMAM/HBV003

N. Kuznetsov, O. Motygin

引用次数: 9

Hydrodynamics of fluid around a collapsing bubble in the spark bubble droplet generation process 火花气泡液滴产生过程中气泡崩塌周围流体的流体力学

IF 0.9 4区工程技术

Quarterly Journal of Mechanics and Applied Mathematics Pub Date : 2014-08-01 DOI: 10.1093/QJMAM/HBU011

A. Dadvand, Mazyar Dawoodian, B. Khoo

{"title":"Hydrodynamics of fluid around a collapsing bubble in the spark bubble droplet generation process","authors":"A. Dadvand, Mazyar Dawoodian, B. Khoo","doi":"10.1093/QJMAM/HBU011","DOIUrl":"https://doi.org/10.1093/QJMAM/HBU011","url":null,"abstract":"Summary This article aims to study in detail the bubble oscillation near confined free surfaces and the ensuing droplet formation using a combined boundary element-finite difference method. Three configurations are considered: (i) the bubble oscillation near a circular aperture made in a flat plate, (ii) the bubble oscillation inside and near the top opening of a vertical cylinder and (iii) the bubble oscillation between a perforated flat plate and a horizontal solid boundary. The effects of standoff distance on the bubble dynamics and on the surrounding fluid dynamics are examined. Completely different bubble shapes, free surface motions, jetting patterns and pressure distributions under different standoff distances could be observed in the present work. In addition, it was found that for the configurations (i) and (iii), the bubble reentrant jet is always directed away from the free surface. For the cylinder case, however, a critical standoff distance was found for which the pressure distribution in the fluid above and below the bubble are the same and the bubble takes the shape of an hourglass at the time of jet impact. For subcritical standoff distances the bubble reentrant jet is always away from the free surface. However, for supercritical standoff distances the direction of the reentrant jet is interestingly directed towards the free surface. Finally, the effect of plate and cylinder configurations on the resulting droplet dynamics was investigated. It was found that the driving force for the droplet formation is the initial velocity induced by the bubble reentrant jet rather than the pressure difference inside the liquid. Besides, in the cylinder case the droplet size is smaller and its pinch-off happens earlier than the plate case.","PeriodicalId":56087,"journal":{"name":"Quarterly Journal of Mechanics and Applied Mathematics","volume":"67 1","pages":"389-417"},"PeriodicalIF":0.9,"publicationDate":"2014-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1093/QJMAM/HBU011","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"61239740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3