Teaching Experiences

  • Present Nov-2015

    Assistant Professor

    Bangladesh University of Engineering and Technology (BUET)

  • November-2015 May-2012

    Lecturer

    Bangladesh University of Engineering and Technology (BUET)

  • May-2012 October- 2011

    Lecturer

    Ahsanullah University of Science and Technology (AUST), Bangladesh

Education & Training

  • Ph.D On going

    Mathematical Modeling on Population Biology

    Bangladesh University of Engineering and Technology (BUET)

  • M. Phil 2017

    Computational Fluid Dynamics (CFD)

    Bangladesh University of Engineering and Technology (BUET)

  • M.Sc 2010

    Applied Mathematics

    University of Dhaka

  • B. Sc 2008

    Mathematics

    University of Dhaka

  • H.S.C 2002

    Science Group

    Jamalpur Govt Ashek Mahmud College

  • S.S.C 2000

    Science Group

    Jamalpur Govt Girl’s High School

Filter by type:

Sort by year:

Blood Flow Analysis Inside A Stenotic Artery Using Power-Law Fluid Model

R. Nasrin, Amzad Hossain, I. Zahan

Abstract

This paper is devoted to study numerically a recent development of a non-Newtonian blood flow model
for a stenosed artery in human blood vessel. For numerical investigation the blood flow modeling
method of this research begins with non-Newtonian power-law model. The governing system of equation
based on incompressible Navier-Stokes equations with externally imposed magnetic resonance has
been generalized to take into account the mechanical properties of blood. The intent of this research
is to examine the effects of inlet velocity and imposed magnetic field on the blood flow throughout the
artery. The Galerkin’s weighted residual method of finite element system has been employed to resolve
the governing system of equation with proper boundary conditions. The numerical simulation has been
conducted for various inlet velocities from 0.005 to 0.1m/s and magnetic field strength from 0 to 6
tesla with superior convergence of the iterative structure. Results have been shown in terms of velocity,
surface plot of velocity, pressure and viscosity contours. Cross-sectional plots of velocity and viscosity
magnitudes across the stenotic contraction have also been displayed graphically. Obtained results of the
blood flow simulations indicate that viscosity increases due to increasing values of inlet velocity of blood
and magnetic strength.

Performance analysis of hybrid/single nanofluids on augmentation of heat transport in lid‐driven undulated cavity

Rehena Nasrin, Saddam Hossain, Ishrat Zahan, Khandker Farid Uddin Ahmed, Hussain Fayaz

Abstract

This numerical study reveals the heat transfer performance
of hybrid/single nanofluids inside a liddriven
sinusoidal trapezoidal‐shaped enclosure. The
right and left inclined surfaces of the trapezium have
been considered as insulated, whereas the bottom
sinusoidal wavy and the flat top surfaces of the enclosure
as hot and cold, respectively. The governing
partial differential equations of fluid's velocity and
temperature have been resolved by applying the finite
element method. The implications of Prandtl number
(4.2‐6.2), Richardson number (0.1‐10.0), undulation
number (0‐3), nanoparticles volume fraction (0%‐3%),
and nanofluid/base fluid (water, water–copper (Cu),
water–Cu–carbon nanotube, water–Cu–copper oxide
(CuO), water–Cu–TiO2, and water–Cu–Al2O3) on the
velocity and temperature profiles have been studied.
Simulated findings have been represented by means
of streamlines, isothermal lines, and average Nusselt
number of above‐mentioned hybrid nanofluids for
varying the governing parameters. The comparison of
heat transfer rates using hybrid nanofluids and pure
water has been also shown. The heat transfer rate is
increased about 15% for varying Richardson number
from 0.1 to 10.0. Blending of two nanoparticles
suspension in base fluid has a higher heat transfer
rate—approximately 5% than a mononanoparticle.
Moreover, a higher average Nusselt number is obtained
by 14.7% using the wavy surface than the flat
surface of the enclosure. Thus, this study showed that
applying hybrid nanofluid may be beneficial to obtain
expected thermal performance.

Mixed convective hybrid nanofluid flow in lid-driven undulated cavity: effect of MHD and Joule heating

Ishrat Zahan, R. Nasrin, M. A. Alim

Abstract

A numerical analysis has been conducted to show the effects of magnetohydrodynamic (MHD) and Joule heating on heat transfer phenomenon in a lid driven triangular cavity. The heat transfer fluid (HTF) has been considered as water based hybrid nanofluid composed of equal quantities of Cu and TiO2 nanoparticles. The bottom wall of the cavity is undulated in sinusoidal pattern and cooled isothermally. The left vertical wall of the cavity is heated while the inclined side is insulated. The two dimensional governing partial differential equations of heat transfer and fluid flow with appropriate boundary conditions have been solved by using Galerkin's finite element method built in COMSOL Multyphysics. The effects of Hartmann number, Joule heating, number of undulation and Richardson number on the flow structure and heat transfer characteristics have been studied in details. The values of Prandtl number and solid volume fraction of hybrid nanoparticles have been considered as fixed. Also, the code validation has been shown. The numerical results have been presented in terms of streamlines, isotherms and average Nusselt number of the hybrid nanofluid for different values of governing parameters. The comparison of heat transfer rate by using hybrid nanofluid, Cu-water nanofluid, TiO2 -water nanofluid and clear water has been also shown. Increasing wave number from 0 to 3 enhances the heat transfer rate by 16.89%. The enhanced rate of mean Nusselt number for hybrid nanofluid is found as 4.11% compared to base fluid.

Effect of Conjugate Heat Transfer on Flow of Nanofluid in a Rectangular Enclosure

Ishrat Zahan, M.A. Alim

Abstract

An elaborate numerical study of developing a model regarding conjugate effect of fluid flow and heat transfer in a heat conducting vertical walled cavity filled with copper-water nanofluid has been presented in this paper. This model is mainly adopted for a cooling of electronic device and to control the fluid flow and heat transfer mechanism in an enclosure. The numerical results have been provided in graphical form showing effect of various relevant non-dimensional parameters. The relevant governing equations have been solved by using finite element method of Galerkin weighted residual approach. The analysis uses a two dimensional rectangular enclosure under conjugate convective conductive heat transfer conditions. The enclosure exposed to a constant and uniform heat flux at the left vertical thick wall generating a natural convection flow. The thicknesses of the remaining parts of the walls are assumed to be zero. The right wall is kept at a low constant temperature, while the horizontal walls are assumed to be adiabatic. A moveable divider is attached at the bottom wall of the cavity. The governing equations are derived for the conceptual model in the Cartesian coordinate system. The study has been carried out for the Rayleigh number Ra =106 and for the solid volume fraction. The investigation is to be arrived out at different non-dimensional governing parameters. The effect of convective heat transfer coefficient, divider position and thickness of solid wall on the hydrodynamic and thermal characteristic of flow has been analyzed. Results are to be presented in terms of streamlines, isotherms and average Nusselt number of the nanofluid for different values of governing parameters.

MHD effect on conjugate heat transfer in a nanofluid filled rectangular enclosure

Ishrat Zahan, R. Nasrin, MA. Alim

Abstract

In the present research a numerical solution has been carried out to investigate the problem of magnetohydrodynamics (MHD) conjugate natural convection flow in a rectangular enclosure filled with copper water nanofluid. The relevant governing equations have been solved numerically by using finite element method of Galerkin weighted residual approach. The investigation uses a two dimensional rectangular enclosure with heat conducting vertical wall and uniform heat flux. The effect of Hartmann number on the parameter Rayleigh number, divider position and solid volume fraction of nano particles on the flow and temperature fields are examined for the range of Hartmann number (Ha) of to 60. Parametric studies of the fluid flow and heat transfer performance of the enclosure for the pertinent parameters have also been performed. The numerical results have been provided in graphical form of streamlines and isotherms for various dimensionless parameters. It is found that the heat transfer rate increases with an increase of Rayleigh number and divider position but it decreases with an increase of the Hartmann number. It is also obtained that an increase of the solid volume fraction enhances the heat transfer performance. Finally, the implications of the above parameters have been depicted on the average Nusselt number of the fluid.

MHD effect on Solid fluid thermal Conductivity Ratio and Wall Thickness in a Nanofluid Filled Enclosure

Ishrat Zahan , M. A. Alim,

Abstract

The study of laminar magnetohydrodynamic (MHD) conjugate natural convection flow on an incompressible, viscous and electrically conducting fluid with heat conducting vertical wall and uniform heat flux is numerically investigated. In the analysis, a two dimensional rectangular enclosure filled with water-Cu nanofluid is used under conjugate convective conduction condition. The left side wall of the enclosure is kept at a constant heat flux which is maintained at ambient air temperature while a constant low temperature is used on the right wall. The horizontal walls are adiabatic. The governing model has been solved by using finite element method with Galerkin weighted residual simulation. The objective of the study is to examine the momentum and energy transport processes in a rectangular enclosure in presence of magnetic field. The outcome are shown in terms of parametric presentations of streamlines and isotherms for the parameter solid fluid thermal conductivity ratio and solid wall thickness on heat transfer and fluid flow inside the cavity for the range of Hartmann number (Ha) of 0 to 60. Moreover, the implications of the above parameters are depicted on the average Nusselt number (Nu) of the fluid. Finally, it is found that heat transfer and fluid flow can be controlled by the thickness of the solid wall and the thermal conductivity ratio.

Radiative Heat and Mass Transfer of an MHD Free Convection Flow Along a Stretching Sheet with Chemical Reaction, Heat Generation and Viscous Dissipation

Ishrat Zahan, M. A. Samad

Abstract

In the present study, an analysis is carried out to investigate the effect of chemical reaction and radiation on a steady two-dimensional magneto-hydrodynamics (MHD) heat and mass transfer free convection flow of a viscous incompressible fluid along a stretching sheet with heat generation along with the effect of viscous dissipation. The basic non-linear partial differential equations governing the flow field are reduced to a system of coupled non-linear ordinary differential equations by similarity transformations and the equations are solved numerically by applying Nachtsheim-Swigert shooting iteration technique along with sixth order Runge-Kutta integration scheme. The numerical results with respect to embedded parameters are displayed graphically for the non-dimensional velocity, temperature and concentration profiles. Finally the effects of the pertinent parameters which are of physical and engineering interest are presented in tabular form.

Hybrid nanofluid flow in combined convective lid-driven sinusoidal triangular enclosure

Ishrat Zahan, R. Nasrin, M. A. Alim

Abstract

A numerical analysis has been carried out on combined magnetoconvection in a lid driven triangular enclosure with sinusoidal wavy bottom surface filled with hybrid nanofluid composed of equal quantities of Cu and Al2O3 nanoparticles dispersed in water-based fluid. The enclosure left vertical wall is heated while the inclined side of the cavity is cooled isothermally and the bottom wavy wall is insulated. A heat conducting horizontal circular cylinder has been placed at the middle of the enclosure. In this research, the relevant governing equations have been solved by using finite element method of Galerkin weighted residual approach. The implication of Richardson number and solid volume fraction of nanoparticles on the flow structure and heat transfer characteristics has been performed in details while the Reynolds number, Hartmann number and Prandtl number considered as fixed. Results have been presented in terms of streamlines, isotherms and average Nusselt number of the hybrid nanofluid for different values of governing parameters. The numerical results indicate that the Richardson number have significance effect on the flow and heat transfer performance. Moreover, it is noticed that combination of two different nanoparticles suspension has a better performance of heat transfer.

Effects of Rayleigh number and Wall Conductivity on Conjugate Natural Convection of Nanofluid in a Heat Conducting Rectangular Vertical Walled Enclosure

Ishrat Zahan , M. A. Alim,

Abstract

The objective of this study is to numerically simulate the effect of conjugate heat transfer in a heat conducting vertical walled cavity filled with Copper-Water nanofluid. The analysis uses a two-dimensional rectangular enclosure under conjugate convective-conductive heat transfer conditions. The enclosure was subject to a constant conduction-convection uniform heat flux at the left wall generating a natural convection flow. The thicknesses of the other boundaries of the wall are assumed to be zero. The right wall is kept at a low constant temperature while the horizontal walls are assumed to be adiabatic. A heat conducting moveable divider is attached on the bottom horizontal wall. The study has been carried out for the Rayleigh number in the range of 104Ra ≤ 106 and for the solid volume fraction 0 ≤ ɸ ≤ 0.05. The investigation is to be arrived out at different non-dimensional governing parameters. The effect of Rayleigh number and solid fluid thermal conductivity ratio on the hydrodynamic and thermal characteristic of flow has been analyzed. Results are to be presented in terms of streamlines, isotherms and average Nusselt number of the nanofluid for different values of governing parameters.

At My Office

Room no.GA-22, 1st floor, Old academic Building, BUET

At My Work

At My Lab