Journal of Engineering Mathematics最新文献_第3页

Numerical simulations of shallow-water sloshing coupled to horizontal vessel motion in the presence of a time-dependent porous baffle 存在随时间变化的多孔挡板时浅水荡流与水平船只运动耦合的数值模拟

IF 1.3 4区工程技术

Journal of Engineering Mathematics Pub Date : 2024-06-24 DOI: 10.1007/s10665-024-10376-w

M. R. Turner

{"title":"Numerical simulations of shallow-water sloshing coupled to horizontal vessel motion in the presence of a time-dependent porous baffle","authors":"M. R. Turner","doi":"10.1007/s10665-024-10376-w","DOIUrl":"https://doi.org/10.1007/s10665-024-10376-w","url":null,"abstract":"Shallow-water fluid sloshing in the Lagrangian Particle Path formulation, with the addition of an energy-extracting porous baffle, is simulated numerically using a symplectic numerical scheme which captures, in an essential way, the energy exchange. The fluid motion in a rectangular vessel is dynamically coupled to a surface-piercing porous baffle. The fluid transmission through the baffle is characterized by a nonlinear Darcy–Forchheimer model equation. The numerical scheme is symplectic, based on the implicit-midpoint rule, and thus is strategically designed to maintain the energy partition between the fluid and vessel throughout numerous time steps. Our results demonstrate the non-conservative nature of the system, with the porous baffle effectively dissipating energy from the overall system. Furthermore, we present findings that demonstrate the role of time-periodic variations in baffle porosity on energy dissipation. By manipulating the frequency and magnitude of this time-dependent variability, it is established that a greater amount of energy can be extracted from the system compared with the optimal fixed porosity baffle. These results shed new light on potential strategies for enhancing energy dissipation in such configurations.","PeriodicalId":50204,"journal":{"name":"Journal of Engineering Mathematics","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141520754","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: 0

Buckling phenomenon of vertical beam/column of variable density carrying a top mass 承载顶部质量的密度可变垂直梁/柱的屈曲现象

IF 1.3 4区工程技术

Journal of Engineering Mathematics Pub Date : 2024-06-24 DOI: 10.1007/s10665-024-10378-8

Mustafa Turkyilmazoglu

{"title":"Buckling phenomenon of vertical beam/column of variable density carrying a top mass","authors":"Mustafa Turkyilmazoglu","doi":"10.1007/s10665-024-10378-8","DOIUrl":"https://doi.org/10.1007/s10665-024-10378-8","url":null,"abstract":"This study focuses on modeling ideal nonuniform standing beams and towers supporting a constant top mass. We also analyze their dynamical stability, as determining the design parameters influencing their shape and stability holds significant value for structural engineering. Initially, we employ a statical mechanics approach to balance the mechanical and gravitational forces. By solving an initial-value problem, we derive the cross-sectional areas of the columns. Our findings reveal that these areas, rather than the shapes, are the primary contributors to the engineering performance of the columns. Additionally, the top mass acts as a multiplying factor for the cross-sectional areas, and the density distribution along the column determines whether the top should be heavier or lighter. Furthermore, we demonstrate that exponential, parabolic, or linear cross-sections with significantly wider base profiles are crucial for accommodating heavier top loads. Moving on to the dynamical analysis, we consider two ideal tower configurations: FC and SC. Numerical and analytical results reveal that higher modes exhibit shorter amplitudes. FC modes necessitate higher design parameters to resist buckling phenomena, whereas SC modes show lower resistance to vibrational deflections. In terms of stability, a heavier top mass enhances the vertical beam’s stability, while towers with parabolic bases are more susceptible to instabilities.","PeriodicalId":50204,"journal":{"name":"Journal of Engineering Mathematics","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141520755","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: 0

A Nusselt number correlation for a superhydrophobic solid sphere encapsulated in a perfect plastron 封装在完美质体中的超疏水性固体球体的努塞尔特数相关性

IF 1.3 4区工程技术

Journal of Engineering Mathematics Pub Date : 2024-06-22 DOI: 10.1007/s10665-024-10377-9

Zavier Berti, M. R. Flynn

{"title":"A Nusselt number correlation for a superhydrophobic solid sphere encapsulated in a perfect plastron","authors":"Zavier Berti, M. R. Flynn","doi":"10.1007/s10665-024-10377-9","DOIUrl":"https://doi.org/10.1007/s10665-024-10377-9","url":null,"abstract":"Surface-attached air bubbles are known to provide lubricating (i.e., drag reducing) benefits but their contribution to inhibiting heat transfer is not as well understood. The present theoretical study considers Stokes flow around a solid sphere and uses matched asymptotic expansions to estimate the degree of thermal insulation offered by an encapsulating air layer of uniform thickness. Key to our analysis is to derive an expression for the Nusselt number in terms of the air layer thickness and the Péclet number, (text{ Pe}_w), of the surrounding liquid, here assumed to be water. This latter parameter, which characterizes advective to diffusive heat transport, is assumed to be small such that our zeroth- and first-order solutions are, respectively, proportional to (text{ Pe}_w^0) and (text{ Pe}_w^1). Although small (text{ Pe}_w) favors small free stream velocities, forced convection will dominate over natural convection only if the free stream velocity (and/or the solid sphere radius) exceeds a certain threshold. This requirement constrains the solution space; on the other hand, it is straightforward to generalize our analysis so that it considers fluid pairs other than water and air.","PeriodicalId":50204,"journal":{"name":"Journal of Engineering Mathematics","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141528911","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: 0

Stabilizing an adverse density difference in the presence of phase change 在出现相变时稳定不利的密度差

IF 1.3 4区工程技术

Journal of Engineering Mathematics Pub Date : 2024-06-18 DOI: 10.1007/s10665-024-10372-0

Lewis Johns, Ranga Narayanan

引用次数: 0

Size-dependent free vibration analysis of multidirectional functionally graded nanobeams via a nonlocal strain gradient theory 通过非局部应变梯度理论对多向功能分级纳米梁进行尺寸相关自由振动分析

IF 1.3 4区工程技术

Journal of Engineering Mathematics Pub Date : 2024-06-01 DOI: 10.1007/s10665-024-10373-z

M. Guerroudj, Ahmed Drai, A. Daikh, Mohammed Sid Ahmed Houari, B. Aour, M. A. Eltaher, M. Belarbi

引用次数: 0

Vertically integrated unconfined groundwater flow on sloping base 倾斜基面上垂直整合的无约束地下水流

IF 1.3 4区工程技术

Journal of Engineering Mathematics Pub Date : 2024-06-01 DOI: 10.1007/s10665-024-10360-4

Otto D. L. Strack

引用次数: 0

Vortex shedding from bluff bodies: a conformal mapping approach 崖体涡流脱落：保形映射法

IF 1.3 4区工程技术

Journal of Engineering Mathematics Pub Date : 2024-05-22 DOI: 10.1007/s10665-024-10367-x

Vijay Matheswaran, Thomas K. DeLillo, L. Scott Miller

引用次数: 0

Melting, Soret and Dufour effect on MHD Casson fluid flow over a stretching sheet with slip conditions 具有滑移条件的拉伸片上 MHD 卡松流体流动的熔融、索雷特和杜富尔效应

IF 1.3 4区工程技术

Journal of Engineering Mathematics Pub Date : 2024-05-22 DOI: 10.1007/s10665-024-10364-0

Surbhi Sharma, Mamta Goyal, Amit Dadheech

引用次数: 0

A generalized approach to solving the mixed boundary value problem governing self-diffusiophoresis 解决自扩散流混合边界值问题的通用方法

IF 1.3 4区工程技术

Journal of Engineering Mathematics Pub Date : 2024-05-21 DOI: 10.1007/s10665-024-10344-4

Alicia Boymelgreen, T. Miloh

引用次数: 0

Alternating minimization algorithm with a probability generating function-based distance measure 基于概率生成函数的距离测量交替最小化算法

IF 1.3 4区工程技术

Journal of Engineering Mathematics Pub Date : 2024-05-18 DOI: 10.1007/s10665-024-10349-z

Ranusha Rajakrishnan, Seng Huat Ong, Choung Min Ng

{"title":"Alternating minimization algorithm with a probability generating function-based distance measure","authors":"Ranusha Rajakrishnan, Seng Huat Ong, Choung Min Ng","doi":"10.1007/s10665-024-10349-z","DOIUrl":"https://doi.org/10.1007/s10665-024-10349-z","url":null,"abstract":"The Expectation Maximization (EM) algorithm, a popular method for maximum likelihood estimation of parameters, requires a complete data space and construction of a conditional expectation. For many statistical models, these may not be straightforward. This paper proposes a simpler Alternating Minimization (AM) algorithm using a probability generating function (pgf)-based divergence measure for estimation in univariate and bivariate distributions. The performance of the estimation method is studied for the negative binomial and Neyman Type-A distributions in the univariate setting, while for bivariate cases, the bivariate Poisson and the bivariate negative binomial distributions are considered. Comparison is made with direct optimization of pgf-based divergence measure and maximum likelihood (ML) estimates. Results produced via AM in both simulated and real-life datasets show an improvement in comparison to direct pgf optimization, especially in the bivariate setting, with the execution time showing an improvement for large sample sizes when compared to ML. Goodness-of-fit tests show that the pgf divergence measure with AM estimates mostly perform similarly to the ML estimates in terms of power of the test.","PeriodicalId":50204,"journal":{"name":"Journal of Engineering Mathematics","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141059987","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: 0