# M. M. RahmanSultan Qaboos University | SQU · Department of Mathematics

M. M. Rahman

Ph.D. in Applied Mathematics

Professor, Sultan Qaboos University, Oman

## About

135

Publications

31,952

Reads

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3,551

Citations

Citations since 2017

Introduction

My general field of research interest is Fluid Dynamics, particularly in the field of Nanofluidic phenomenon, Heat and Mass Transfer, MHD, Transport in Porous Media and Bio-Fluid Flows. My research group “Modelling of Nanofluid Flows” was awarded the “Most Active Research Group Award 2019” by the Sultan Qaboos University. Currently, we are working on magnetic nanofluids, transport of nanofluids in porous media under LTNE, and on the stability of Maxwell-Cattaneo fluids. I secured several grants.

Additional affiliations

June 2020 - present

May 2012 - June 2020

August 2008 - May 2012

Education

September 2000 - September 2003

January 1994 - December 1994

January 1991 - December 1993

## Publications

Publications (135)

In this article, we use magnetic nanoparticles to explore the three‐dimensional natural upward force flow within a quadrangular cuboid under the influence of a sloping magnetic flux. We consider three forms of thermic conditions on the bottom surface of the cavity, such as uniform surface temperature, constant heat flux, and temperature varied para...

Purpose
This paper aims to investigate numerically the free convective heat transfer efficiency inside a rectotrapezoidal enclosure filled with Al 2 O 3 –Cu/water hybrid fluid. The bottom wall of the cavity is uniformly heated, the upper horizontal wall is insulated, and the remaining walls are considered cold. A new thermophysical relation determi...

This paper presents a thermal instability analysis for the natural convective heat transport within a horizontal layer filled with nanoparticles using non-homogeneous dynamic model, which is performed analytically and numerically. For the linear stability analysis, both the oscillatory and non-oscillatory convection for free-free boundaries is inve...

We explore numerically the Darcy–Boussinesq convective flow of water, kerosene, and engine oil through the glass ball, aluminum foam and sandstone porous medium inside a right-angle trapezoidal enclosure taking into consideration of thermal stratification. The bottom and left walls of the enclosure are uniformly heated, whereas thermal insulation i...

Forced convection in laminar and turbulent regimes in porous channels received a considerable experimental and numerical development focussing on enhancing heat transfer and reducing pressure drop. Different types of fluids such as water, nanofluid, and hybrid fluids have been used as working fluids to reject heat from the cooled surfaces. In the p...

Nanofluid is a new class of fluid that aims to enhance heat transfer. Nanoparticles sedimentation may play a role in the heat extractions from a hot surface. Brownian and thermophoretic effects may help in understanding the sedimentation effects. In the present paper, we attempted to investigate these phenomena (Brownian motion and thermophoretic e...

Thermohydromagnetic performances of alumina–water nanofluid in a trapezoidal vessel that considered the inclined magnetic field were investigated numerically. The bottom wall of the enclosure is heated uniformly, whereas the upper wall is adiabatic. The remaining walls are kept cold. The mathematical problem was tackled through the Galerkin finite...

Nanofluids have enjoyed a widespread use in many technological applications due to their peculiar properties. Numerical simulations are presented about the unsteady behavior of mixed convection of Fe3O4-water, Fe3O4-kerosene, Fe3O4-ethylene glycol, and Fe3O4-engine oil nanofluids inside a lid-driven triangular cavity. In particular, a two-component...

Due to the growing needs of super coolant for industrial applications, in this article, we investigate experimentally as well as numerically the possible best heat transfer fluid. In this respect, we considered three nanofluids mixtures of Al2O3/water (concentrations of 0.2%vol and 0.3%vol) and 0.2%vol Fe3O4/water and 0.2%vol ND‐Fe3O4/water, and a...

Copper oxide makes an excellent nanomaterial for various efficient heat transfer devices because of its high specific surface area, lightweight, high specific heat capacity, and high thermal conductivity. Heat transfer intensification using nanofluids has strong potential to improve innovative cost-efficient chilling technologies. The present study...

Adding nanoparticles to fluid has led to a new class of fluids named as nanofluids.
Different concentrations and its effective cooling have attracted many engineering applications to
test this new fluid. Lately, important heat enhancement has been observed by dispersing two
distinct nanoparticles in the regular fluid. This type of hybrid nanofluid...

This paper investigates the entropy generations due to the multiple factors such as base fluid, nanoparticles, viscosity, and the inclined magnetic field for the convective flow of nanofluids inside a titled square enclosure considering local thermal nonequilibrium (LTNE) conditions. One of the walls of the enclosure is kept heated changing its pos...

Our present work studies the impacts of variable porosity and variable permeability on the transient buoyancy-induced heat transmission flow of Cu–H2O nanofluid through a holey medium (glass bead, aluminum foam and sandstone) inside a right-angle trapezoidal cavity considering thermal nonequilibrium states amid the solid matrix and the nanofluid. W...

Heat enhancement and heat storage are becoming important engineering topics related to renewable energy. Different fluid classes have been proposed, and various types of phase change materials have been used for energy storage. Nanofluids, which consist of nano metallic particles in liquids such as water, have been receiving a lot of attention rece...

In the present paper, unsteady natural convective heat transfer flow inside a square enclosure filled with nanofluids containing magnetic nanoparticles using nonhomogeneous dynamic model is investigated numerically. The horizontal top wall of the enclosure is considered a colder wall and the bottom wall is maintained at uniform temperature whereas...

Unsteady natural convection flow and heat transfer utilizing magnetic nanoparticles in the presence of a sloping magnetic field inside a square enclosure are simulated numerically following nonhomogeneous dynamic model. Four different thermal boundary conditions: constant, parabolic in space, sinusoidally in space, and time for the bottom hot wall...

In this work steady natural convection flow energized by an exothermic chemical reaction administered by Arrhenius kinetics inside a tilted nanofluid saturated porous square cavity under the action of a sloping magnetic field has been deliberated numerically following Buongiorno nanofluid model. It is assumed that there is a local thermal equilibri...

Two-dimensional transient natural convective flow in a vertical tube of plain and uneven side-walls containing cobalt-kerosene nanofluids is analyzed using a nonhomogeneous dynamic model. The vertical right wall of the enclosure is maintained at a constant low temperature and the left wall is heated by a uniform thermal condition whereas the horizo...

Two-dimensional transient natural convective flow in a vertical tube of plain and uneven side-walls containing cobalt-kerosene nanofluids is analyzed using a nonhomogeneous dynamic model. The vertical right wall of the enclosure is maintained at a constant low temperature and the left wall is heated by a uniform thermal condition whereas the horizo...

In this paper, the time-dependent natural convective heat transport in homocentric annuli containing nanofluids accompanying an oriented magnetic field using a nonhomogeneous dynamic mathematical model is numerically investigated. The analysis is carried out for four different shapes of inner walls such as triangular, square, elliptical and cylindr...

In this paper, the local thermal nonequilibrium conditions between the base fluid and the nanoparticles inside an inclined square enclosure have been investigated and analyzed numerically. The effects of magnetic field intensity and the geometry inclination angle on the heat exchange between base fluid and nanoparticles are also taken into account....

This paper analyzes heat transfer and fluid flow of natural convection in an inclined square enclosure filled with different types of nanofluids having various shapes of nanoparticles in the presence of oriented magnetic field. The Galerkin weighted residual finite element method has been employed to solve the governing non-dimensional partial diff...

In the present study, the detailed procedures of Galerkin weighted residual technique of finite element method (FEM) for solving two-dimensional incompressible natural convective flow of nanofluids using nonhomogeneous dynamic model are discussed for the first time. The physical domain is discretized by using unstructured triangular elements. The g...

In this paper, natural convective heat transfer flow inside an inclined square enclosure filled with different types of nanofluids having various shapes of the nanoparticles are investigated numerically using Galerkin weighted residual finite element technique. The effects of the Brownian diffusion of the nanoparticles, uniform heat source position...

In this paper, we have investigated unsteady natural convection flow and heat transfer inside a trapezoidal enclosure filled with nine different types of nanofluids having various shapes of the nanoparticle following Tiwari and Das mathematical model. The left and right walls of the enclosure are kept at different temperatures, while the top and bo...

In this paper three-dimensional axisymmetric stagnation-point boundary layer flow of nanofluids over a striated surface with anisotropic slip is analyzed considering various thermal boundary conditions and nanoparticle volume fractions. The mathematical nanofluid model of Buongiorno has been used. Using appropriate similarity transformations, the b...

In this paper, we have studied the problem of two-dimensional transient convective flow and heat transfer in nanofluids in a quarter-circular shape enclosure using newly proposed nonhomogeneous dynamic mathematical model. The round wall of the enclosure is maintained at constant low temperature and the variable thermal condition on the bottom heate...

In this paper, the problem of unsteady natural convective flow of nanofluids inside a semicircular shaped enclosure using the newly developed nonhomogeneous dynamic model has been investigated numerically. The Galerkin weighted residual finite element technique has been employed to solve the governing nonlinear and coupled dimensionless partial dif...

The analytical and numerical studies are performed to investigate the non-uniform heat generation/absorption effect on the boundary layer flow of an incompressible, electrically conducting nanofluid over a vertical plate in the presence of thermal radiation. The highly nonlinear governing equations along with the boundary conditions are converted i...

In this paper, the problem of unsteady convective flow of nanofluid in a horizontal semicircular-annulus using nonhomogeneous dynamic mathematical model has been investigated. The outer wall of the annulus is considered a colder wall and the inner is maintained at three different temperatures (constant, quadratic and sinusoidal) while two other wal...

Finite element simulation is performed visualizing heat flow through heatlines for a free convection flow and heat transfer in an air-filled prismatic enclosure. This configuration has applications in collecting solar energy in attic spaces of greenhouses and buildings having pitched roofs. The top inclined walls of the enclosure are considered at...

This paper deals with the problem of unsteady, laminar forced convective heat and mass
transfer flow of a viscous incompressible fluid with thermophoresis due to a porous rotating disk in the
presence of partial slip and magnetic field. The numerical simulation is carried out for the solution of
nonlinear partial differential equations by applying...

In this paper, we investigate the effects of second-order slip and magnetic field on the nonlinear mixed convection stagnation-point flow toward a vertical permeable stretching/shrinking sheet in an upper convected Maxwell (UCM) fluid with variable surface temperature. Numerical results are obtained using the bvp4c function from matlab for the redu...

The aim of the present study is to analyze numerically the steady boundary layer flow and heat transfer characteristics of Casson fluid with variable temperature and viscous dissipation past a permeable shrinking sheet with second order slip velocity. Using appropriate similarity transformations, the basic nonlinear partial differential equations h...

Purpose
– The laminar two-dimensional stagnation-point flow and heat transfer of a viscous incompressible nanofluid obliquely impinging on a shrinking surface is formulated as a similarity solution of the Navier-Stokes, energy and concentration equations. The model used for the nanofluid incorporates the effects of Brownian motion and thermophoresi...

This paper deals a numerical study of unsteady two-dimensional laminar forced convective hydrodynamic heat and mass transfer flow of a nanofluid along a porous wedge. The model incorporates the effects of thermophoresis and Brownian motion in the presence of variable suction. The dimensionless local similarity equations governing the model are solv...

In this paper we analyze unsteady two dimensional hydromagnetic forced convective heat transfer flow of a viscous incompressible micropolar fluid along a permeable wedge with convective surface boundary condition. The potential flow velocity has been taken as a function of the distance x and time t. The governing time dependent non-linear partial d...

This paper investigates thermophoretic deposition of micron sized particles on unsteady forced convective heat and mass transfer flow due to a rotating disk. Using similarity transformations the governing nonlinear partial differential equations are transformed into a system of ordinary differential equations that are then solved numerically by app...

The mixed convection boundary-layer flow on a vertical surface with an applied convective boundary condition is considered. Specific forms for the outer flow and surface heat transfer parameter are taken to reduce the problem a similarity system, which is seen to involve three parameters: m, the exponent of the outer flow; λ, the mixed convection p...

Purpose
– The purpose of this paper is to numerically solve the problem of steady boundary layer flow of a nanofluid past a permeable exponentially shrinking surface with convective surface condition. The Buongiorno’s mathematical nanofluid model has been used.
Design/methodology/approach
– Using appropriate similarity transformations, the basic p...

In this paper we have studied the problem of an unsteady hydromagnetic forced convective heat transfer slip flow over a porous rotating disk taking into account the temperature dependent density, viscosity and thermal conductivity. The governing non-linear partial differential equations of the flow are transformed into a set of non-linear ordinary...

This paper analyzes the combined effects of buoyancy force, mass flux, and variable surface temperature on the stagnation point flow and heat transfer due to a Jeffery fluid over a vertical surface.The governing nonlinear partial differential equations are transformed into a system of coupled nonlinear ordinary differential equations using similari...

In this paper we have studied the effects of temperature dependent fluid properties such as density, viscosity and thermal conductivity and variable Prandtl number on unsteady convective heat transfer flow over a porous rotating disk. Using similarity transformations we reduce the governing nonlinear partial differential equations for flow and heat...

The aim of this paper is to investigate numerically the steady boundary layer flow and heat transfer characteristics of nanofluids using Buongiorno's model past a permeable exponentially shrinking/stretching surface with second order slip velocity. Using appropriate similarity transformations, the basic nonlinear partial differential equations are...

This work investigates the thermophoretic deposition effect on a transient free convection hydromagnetic flow along an accelerated infinite inclined permeable surface in the presence of heat generation, suction (or injection), thermal diffusion, and diffusion-thermo taking into account that the surface temperature and concentration are time depende...

In this paper we investigate numerically the hydromagnetic boundary layer flow and heat transfer characteristics of a nanofluid using three types of nanoparticles (copper, aluminium oxide and titanium dioxide) having various shapes (spherical, cylindrical, arbitrary, etc) by considering three kinds of base fluids (water, ethylene glycol and engine...

A physical model is developed considering nonlinear slip flow with temperature dependent transport properties such as fluid viscosity and thermal conductivity over a wedge in the presence of space and temperature dependent heat generation (or absorption). The surface of the wedge is considered to be heated by the convection current from a hot fluid...

Heat transfer characteristics of a two-dimensional steady hydromagnetic natural convection flow of nanofluids over a non-linear stretching sheet taking into account the effects of radiation and convective boundary condition has been investigated numerically. The model used for the nanofluid incorporates the effects of Brownian motion and thermophor...

Two-dimensional steady natural convection heat transfer to water based nanofluids (TiO2-water, Al2Ol2-water, and Cu-water) flowing over a stretching cylinder has been investigated numerically. Using the similarity transformations, the continuity, momentum, and energy equations are reduced to a set of nonlinear, ordinary differential equations. Thes...

Nonlinear forced convective hydromagnetic flow of an unsteady biomagnetic fluid over a wedge with convective surface has been analyzed numerically. The highly nonlinear coupled governing equations for the momentum, energy, angular momentum for the blood corpuscles and the magnetic induction are reduced to ordinary differential similarity equations...

In this paper, we study the combined effects of internal heat generation and higher order chemical reaction on a steady two‐dimensional non‐Darcian forced convective flow of a viscous incompressible fluid with variable dynamic viscosity and thermal conductivity in a fluid saturated porous medium passing over a linear stretching sheet. Using similar...

This paper presents heat transfer process in a two-dimensional steady hydromagnetic convective flow of an electrically conducting
fluid over a flat plate with partial slip at the surface of the boundary subjected to the convective surface heat flux at
the boundary. The analysis accounts for both temperature-dependent viscosity and temperature depen...

Convective slip flow of slightly rarefied fluids over a wedge with thermal jump and temperature dependent transport properties such as fluid viscosity and thermal conductivity is studied numerically. Due to the appearance of a slip condition at the surface of the boundary no self similar solution can be found. Locally similar solutions are obtained...

In this paper we investigate convective heat transfer characteristics of steady hydromagnetic slip flow over a porous rotating disk taken into account the temperature dependent density, viscosity and thermal conductivity in the presence of Hall current, viscous dissipation and Joule heating. Using von-Karman similarity transformations we reduce the...

The dynamics of two compositionally buoyant columns of fluid rising in an infinite less buoyant fluid is studied in the presence of a uniform magnetic field, B 0. The fluid is thermally stably stratified and has a viscosity, ν, a thermal diffusivity, κ and magnetic diffusivity, η. The stability of the mean state to infinitesimal disturbances is gov...

In this paper we investigate the effects of thermophoresis on the forced convective laminar flow of a viscous incompressible fluid due to a rapidly rotating disk whose surface temperature is lower than the temperature of its surrounding fluid. The governing equations of continuity, momentum, energy and concentration are transformed using similarity...

In this paper we describe in detail spectral solution method for solving nonlinear mean field dynamo equations without inertial effects in a rapidly rotating spherical shell filled with electrically conducting fluid taken into account no-slip velocity boundary conditions in the core for a finitely conducting inner core and an insulating mantle. Sam...

The effects of variable electric conductivity and temperature dependent viscosity on hydromagnetic heat and mass transfer flow along a radiate isothermal inclined permeable surface in a stationary fluid in the presence of internal heat generation (or absorption) are analyzed numerically presenting local similarity solutions for various values of th...

This paper studies the heat transfer process in a two-dimensional steady hydromagnetic natural convective flow of a micropolar fluid over an inclined permeable plate subjected to a constant heat flux condition. The analysis accounts for both temperature dependent viscosity and temperature dependent thermal conductivity. The local similarity equatio...

An analysis has been carried out to obtain the effects of higher order chemical reaction on flow and mass transfer characteristics, of micropolar fluids past a nonlinear permeable stretching sheet immersed in a porous medium with variable concentration of the reactant. The local similarity solutions for the flow, microrotation and mass transfer are...

This paper investigates the effects of the fluid electric conductivity, non-uniform heat source (or sink), suction and variable surface heat flux on the two-dimensional steady hydromagnetic convective flow of a micropolar fluid (in comparison with the Newtonian fluid) flowing along an inclined permeable flat plate embedded in a fluid saturated poro...

An unsteady two-dimensional convective flow of a micropolar fluid along a moving vertical porous flat plate in the presence of a magnetic field has been studied numerically. The governing time-dependent boundary-layer equations are reduced to a set of non-linear ordinary differential equations by introducing a new class of similarity transformation...