检索结果-南通市图书馆

Propulsion and Power Research 2017年第1期6卷 31-40页

作者： Macha Madhu Naikoti Kishan Ali j.chamkha Department of Mathematics Osmania UniversityHyderabad-7TSIndia Mechanical Engineering Department Prince Mohammad Bin Fahd UniversityAl-Khobar 31952Kingdom of Saudi Arabia

The problem of unsteady magnetohydrodynamic(MHD)boundary layer flow of a non-Newtonian Maxwell nanofluid over a stretching surface with thennal radiation is *** Maxwell model is used to characterize the non-Newtonian fluid *** appropriate similarity transformation Is employed to transform the governing partial differential equations of mass,momentum,energy and nanoparticle concentration into ordinary differential *** coupled non-linear ordinary differential equations are solved by using the variational finite element *** flow features and the heat transfer characteristics and nanoparticle volume fraction are analyzed and discussed in detail for several sets of values of the governing flow *** results for the skin-friction coefficient,local Nusselt number and the local Sherwood number are presented in tables for various values of the flow controlling parameters.

关键词： Unsteady flow Stretching surface Maxwell nanofluid Magnetohydrodynamic(MHD) Thermal radiation

Three-dimensional analysis of natural convection in nanofluid-filled parallelogrammic enclosure opened from top and heated with square heater

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

journal of Central South University 2019年第5期26卷 1077-1088页

作者： Abdullah A.A.A AL-RASHED Walid HASSEN Lioua KOLSI Hakan F. OZTOP Ali j. chamkha Nidal ABU-HAMDEH Department of Automotive and Marine Engineering Technology College of Technological Studiesthe Public Authority for Applied Education and TrainingKuwait Unité de Métrologie et des Systèmes énergétiques école Nationale d’IngénieursMonastirUniversity of MonastirTunisia College of Engineering Mechanical Engineering DepartmentHail UniversityHail CitySaudi Arabia Dept.Mech.Engineering Technology FacultyFirat UniversityTR-23119ElazigTurkey Department of Mechanical Engineering King Abdulaziz UniversityJeddahSaudi Arabia Mechanical Engineering Department Prince Sultan Endowment for Energy and EnvironmentPrince Mohammad Bin Fahd UniversityAl-Khobar 31952Saudi Arabia RAK Research and Innovation Center American University of Ras Al KhaimahP.O.Box 10021Ras Al KhaimahUnited Arab Emirates

A numerical study based on the finite volume method has been performed to study the three-dimension natural convection in a parallelogrammic top side opened cavity filled nanofluid with partially heated square at the bottom *** are obtained for different governing parameters such as nanoparticle concentration (φ) from 0 to 0.05,inclination angle of the back and front walls (α) from 5° to 75°,Rayleigh number from 10^3 to 10^5,and length of heater changer from 0.1 to *** main finding from the obtained result showed that the inclination angle and nanoparticle volume fraction affect the flow structure and enhance the heat transfer.

关键词： 3D analysis open enclosure partial heating parallelogram nanofluids

Regression analysis and features of negative activation energy for MHD nanofluid flow model:A comparative study

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Propulsion and Power Research 2023年第2期12卷 273-283页

作者： B.Kumara Prachi Abhinav Singhal R.Nandkeolyar Pulkit Kumar Ali j.chamkha School of Mathematics Thapar Institute of Engineering and TechnologyPatiala 147004PunjabIndia Department of Applied Sciences and Humanities RITRoorkee 247667India School of Sciences Christ(Deemed to be University)Delhi NCR 201003India Department of Mathematics National Institute of TechnologyJamshedpur 831014India Department of Applied Mechanics Indian Institute of TechnologyDelhi 110016India Faculty of Engineering Kuwait College of Science and TechnologyDoha DistrictKuwait

This article elucidates the impact of activation energy on magnetohydrodynamic(MHD)stagnation point nanofluid flow over a slippery surface in a porous regime with thermophoretic and Brownian *** activation energy is scarce in practice,but the impact of negative activation energy could not be neglected as it is noticed in chemical *** rate of some Arrhenius-compliant reactions is retarded by increasing the temperature and is therefore associated with negative activation energies,such as exothermic binding of urea or *** some processes,the temperature dependence of the pressure-induced unfolding and the urea-induced unfolding of proteins at ambient pressure give negative activation *** present mathematical model is solved with successive linearization method(a spectral technique).A comparison of results is made for negative and positive values of activation *** from it,the quadratic multiple regression model is discussed briefly and explained with bar *** is observed that with rise in unsteadiness parameter from 0 to 1(taking positive activation energy),skin friction and Sherwood number are increased by 9.36%and 19%respectively,and Nusselt number is decreased by 26%.However,for negative activation energy,9.36%and 112%enhancement is observed in skin friction and Sherwood number,respectively.

关键词： Negative activation energy Regression analysis Successive linearization method Porous medium

Transient free convection flow of a viscoelastic fluid over vertical surface

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2010年第5期31卷 557-564页

作者： H. M. DUWAIRI R. A. DAMSEH A. j. chamkha M. S. ABDEL-jABER Mechanical Engineering Department Faculty of Engineering and Technology The University of Jordan Mechanical Department Al-Husun University College Albalqa Applied University Manufacturing Engineering Department The Public Authority for Applied Education and Training Civil Engineering Department Faculty of Engineering and Technology The University of Jordan

In this paper, the viscoelsatic boundary layer flow and the heat transfer near a vertical isothermal impermeable surface and in a quiescent fluid are examined. The governing equations are formulated and solved numerically using MackCormak＇s technique. The results show excellent agreement with previously published results by a comparision. Representative results for the velocity and temperature profiles, boundary layer thicknesses, Nusselt numbers, and local skin friction coefficients are shown graphically for different values of viscoelsatic parameters. In general, it is found that the velocities increase inside the hydrodynamic boundary layers and the temperatures decrease inside the thermal boundary layers for the viscoelsatic fluid as compared with the Newtonian fluid due to favorable tensile stresses. Consequently, the coefficients of friction and heat transfer enhance for higher viscoelsatic parameters.

关键词： viscoelastic flows transient free convection heat transfer

Insight into the relationship between non-linear mixed convection and thermal radiation:The case of Newtonian fluid flow due to non-linear stretching

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Propulsion and Power Research 2023年第1期12卷 153-165页

作者： Amit Kumar Pandey Krishnendu Bhattacharyya Anil Kumar Gautam Sohita Rajput Mani Shankar Mandal Ali j.chamkha Dhananjay Yadav Department of Mathematics Institute of ScienceBanaras Hindu UniversityVaranasi-221005Uttar PradeshIndia Department of Mathematics Government General Degree CollegeKalnaeIBurdwan-713405West BengalIndia Faculty of Engineering Kuwait College of Science and TechnologyDoha DistrictKuwait Department of Mathematical and Physical Sciences University of NizwaOman

The current research focuses the light on the characterization of buoyancy-driven non-linear mixed convection and non-linear radiation in a Newtonian flow over a nonlinearly stretching vertical sheet,and this type of flow has useful applications in many industrial processes,such as the paper and pulp industry,polymer industry,electronic device cooling,solar collectors,gas turbine plants,and nuclear *** appropriate transformations,governing PDEs for non-linear mixed convection are reduced to higher-order non-linear ODEs and those are numerically *** with tabular presentations of computed results,the graphical representations are generated to elucidate the effects of involved parameters on convection transport properties and their *** demonstrates that flow velocity increases near the surface and decreases away from the surface as the non-linear convection parameter ***,increments in the thermal buoyancy,temperature ratio and non-linear radiation parameters result in the boost of *** temperature decreases as linear and non-linear buoyancy-related parameters(non-linear convection and thermal buoyancy parameters)are of higher *** contrast,the temperature rises with two non-linear thermal radiation-related parameters(thermal ratio and non-linear radiation parameters).For greater values of the non-linear stretching related parameter,a lower velocity and a higher temperature are *** non-linear convection,thermal buoyancy,thermal ratio and non-linear radiation parameters contribute toward the reduction of the magnitude of surface-drag force and growth of the surface cooling ***,with the non-linearity in surface stretching there are significant percentage hikes of surface-drag force magnitude and surface cooling rate.

关键词： Non-linear mixed convection Non-linear thermal radiation Non-linear stretching sheet Newtonian fluid

Influence of various shapes of nanoparticles on unsteady stagnation-point flow of Cu-H_(2)O nanofluid on a flat surface in a porous medium:A stability analysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2022年第4期31卷 404-413页

作者： Astick Banerjee Krishnendu Bhattacharyya Sanat Kumar Mahato Ali j.chamkha Department of Mathematics Sidho-Kanho-Birsha UniversityPurulia 723104India Department of Mathematics Institute of ScienceBanaras Hindu UniversityVaranasi 221005India Faculty of Engineering Kuwait College of Science and TechnologyDoha DistrictKuwait

The nanofluid and porous medium together are able to fulfill the requirement of high cooling rate in many engineering ***,here the impact of various shapes of nanoparticles on unsteady stagnation-point flow of Cu-H_(2)O nanofluid on a flat surface in a porous medium is ***,the thermal radiation and viscous dissipation effects are *** problem governing partial differential equations are converted into self-similar coupled ordinary differential equations and those are numerically solved by the shooting *** computed results can reveal many vital findings of practical ***,dual solutions exist for decelerating unsteady flow and for accelerating unsteady and steady flows,the solution is *** presence of nanoparticles affects the existence of dual solution in decelerating unsteady flow only when the medium of the flow is a porous *** different shapes of nanoparticles are not disturbing the dual solution existence range,though it has a considerable impact on thermal conductivity of the *** shapes of nanoparticles act differently to enhance the heat transfer characteristics of the base fluid,i.e.,the water *** the other hand,the existence range of dual solutions becomes wider for a larger permeability parameter related to the porous *** the cooling rate of the heated surface,it rises with the permeability parameter,shape factor(related to various shapes of Cu-nanoparticles),and radiation *** surface drag force becomes stronger with the permeability ***,with growing values of nanoparticle volume fraction,the boundary layer thickness(BLT)increases and the thermal BLT becomes thicker with larger values of shape *** decelerating unsteady flow,the nanofluid velocity rises with permeability parameter in the case of upper branch solution and an opposite trend for the lower branch is *** thermal BLT is thicker with radiation *** to the ex

关键词： Cu-H_(2)O nanofluid various shapes of nanoparticles unsteady stagnation-point flow dual solutions stability analysis

Application of Multi-Step Differential Transform Method on Flow of a Second-Grade Fluid over a Stretching or Shrinking Sheet

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

American journal of Computational Mathematics 2011年第2期1卷 119-128页

作者： M.M Rashidi Ali j. chamkha M Keimanesh 不详

In this study, a reliable algorithm to develop approximate solutions for the problem of fluid flow over a stretching or shrinking sheet is proposed. It is depicted that the differential transform method (DTM) solutions are only valid for small values of the independent variable. The DTM solutions diverge for some differential equations that extremely have nonlinear behaviors or have boundary-conditions at infinity. For this reason the governing boundary-layer equations are solved by the Multi-step Differential Transform Method (MDTM). The main advantage of this method is that it can be applied directly to nonlinear differential equations without requiring linearization, discretization, or perturbation. It is a semi analytical-numerical technique that formulizes Taylor series in a very different manner. By applying the MDTM the interval of convergence for the series solution is increased. The MDTM is treated as an algorithm in a sequence of intervals for finding accurate approximate solutions for systems of differential equations. It is predicted that the MDTM can be applied to a wide range of engineering applications.

关键词： Non-Newtonian Fluid Stretching Surface Shrinking Sheet Multi-Step Differential Transform Method (MDTM)

Natural Convection of Water-Based Nanofluids in a Square Enclosure with Non-Uniform Heating of the Bottom Wall

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

journal of Modern Physics 2013年第2期4卷 147-159页

作者： Nader Ben-Cheikh Ali j. chamkha Brahim Ben-Beya Taieb Lili Département de Physique Faculté des Sciences de Tunis Campus Universitaire El-Manar Tunisia Manufacturing Engineering Department The Public Authority for Applied Education and Training Shuweikh Kuwait

In this paper, a numerical study of natural convection in a square enclosure with non-uniform temperature distribution maintained at the bottom wall and filled with nanofluids is carried out using different types of nanoparticles. The remaining walls of the enclosure are kept at a lower temperature. Calculations are performed for Rayleigh numbers in the range 5 × 103 ≤ Ra ≤ 106 and different solid volume fraction of nanoparticles 0 ≤ χ ≤ 0.2. An enhancement in heat transfer rate is observed with the increase of nanoparticles volume fraction for the whole range of Rayleigh numbers. It is also observed that the heat transfer enhancement strongly depends on the type of nanofluids. For Ra = 106, the pure water flow becomes unsteady. It is observed that the increase of the volume fraction of nanoparticles makes the flow return to steady state.

关键词： Natural Convection Unsteady State Nanofluids Solid Volume Fraction Heat Transfer Enhancement