Imran Ullah

Imran Ullah


Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 April 2017 in Journal of King Saud University – Science
Verified
Journal Article
Open access
IUImran Ullah
Imran Ullah
SSSharidan Shafie
Sharidan Shafie
IKIlyas Khan
Ilyas Khan
The effect of slip condition on MHD free convective flow of non-Newtonian fluid over a nonlinearly stretching sheet saturated in porous medium with Newtonian heating is analyzed. The governing nonlinear coupled partial differential equations with auxiliary conditions are transformed into the system of coupled ordinary differential equations via similarity transformations and then solved numerically using Keller-box method. The results for skin friction coefficient and the reduced Nusselt number are obtained and compared with previous results in the literature and are found to be in excellent agreement. Results show that the slip parameter reduces the velocity of Casson fluid and enhances the shear stress. It is also observed that slip effect is more pronounced on temperature profile in comparison with velocity profile. It is also seen that velocity and dimensionless temperature are increasing functions of Newtonian heating parameter. Further, temperature gradient is an increasing function of thermal buoyancy parameter and Newtonian heating parameter whereas a decreasing function of porosity parameter and nonlinear stretching sheet parameter

1 June 2020 in Heliyon
Verified
Journal Article
Open access
AJAhmad Banji Jafar
Ahmad Banji Jafar
SSSharidan Shafie
Sharidan Shafie
IUImran Ullah
Imran Ullah
In this article, we numerically investigate the influence of thermal radiation and heat generation on the flow of an electrically conducting nanofluid past a nonlinear stretching sheet through a porous medium with frictional heating. The partial differential equations governing the flow problems are reduced to ordinary differential equations via similarity variables. The reduced equations are then solved numerically with the aid of Keller box method. The influence of physical parameters such as nanoparticle volume fraction ϕ, permeability parameter K, nonlinear stretching sheet parameter n, magnetic field parameter M, heat generation parameter Q and Eckert number Ec on the flow field, temperature distribution, skin friction and Nusselt number are studied and presented in graphical illustrations and tabular forms. The results obtained reveal that there is an enhancement in the rate of heat transfer with the rise in nanoparticle volume fraction and permeability parameter. The temperature distribution is also influenced with the presence of K, Q, R and ϕ. This shows that the solid volume fraction of nanoparticle can be used in controlling the behaviours of heat transfer and nanofluid flows.

24 October 2016 in PLOS ONE
Verified
Journal Article
Open access
PDF file
IUImran Ullah
Imran Ullah
KBKrishnendu Bhattacharyya
Krishnendu Bhattacharyya
SSSharidan Shafie
Sharidan Shafie
IKIlyas Khan
Ilyas Khan
Numerical results are presented for the effect of first order chemical reaction and thermal radiation on mixed convection flow of Casson fluid in the presence of magnetic field. The flow is generated due to unsteady nonlinearly stretching sheet placed inside a porous medium. Convective conditions on wall temperature and wall concentration are also employed in the investigation. The governing partial differential equations are converted to ordinary differential equations using suitable transformations and then solved numerically via Keller-box method. It is noticed that fluid velocity rises with increase in radiation parameter in the case of assisting flow and is opposite in the case of opposing fluid while radiation parameter has no effect on fluid velocity in the forced convection. It is also seen that fluid velocity and concentration enhances in the case of generative chemical reaction whereas both profiles reduces in the case of destructive chemical reaction. Further, increase in local unsteadiness parameter reduces fluid velocity, temperature and concentration. Over all the effects of physical parameters on fluid velocity, temperature and concentration distribution as well as on the wall shear stress, heat and mass transfer rates are discussed in detail.

12 April 2019 in Symmetry
Verified
Journal Article
Open access
PDF file
IUImran Ullah
Imran Ullah
TATawfeeq Abdullah Alkanhal
Tawfeeq Abdullah Alkanhal
SSSharidan Shafie
Sharidan Shafie
KNKottakkaran Sooppy Nisar
Kottakkaran Sooppy Nisar
IKIlyas Khan
Ilyas Khan
OMOluwole Daniel Makinde
Oluwole Daniel Makinde
The aim of the present analysis is to provide local similarity solutions of Casson fluid over a non-isothermal cylinder subject to suction/blowing. The cylinder is placed inside a porous medium and stretched in a nonlinear way. Further, the impact of chemical reaction, viscous dissipation, and heat generation/absorption on flow fields is also investigated. Similarity transformations are employed to convert the nonlinear governing equations to nonlinear ordinary differential equations, and then solved via the Keller box method. Findings demonstrate that the magnitude of the friction factor and mass transfer rate are suppressed with increment in Casson parameter, whereas heat transfer rate is found to be intensified. Increase in the curvature parameter enhanced the flow field distributions. The magnitude of wall shear stress is noticed to be higher with an increase in porosity and suction/blowing parameters.

28 November 2016 in Discover Nano
Verified
Journal Article
Open access
PDF file
IUImran Ullah
Imran Ullah
IKIlyas Khan
Ilyas Khan
SSSharidan Shafie
Sharidan Shafie
In the present work, the effects of chemical reaction on hydromagnetic natural convection flow of Casson nanofluid induced due to nonlinearly stretching sheet immersed in a porous medium under the influence of thermal radiation and convective boundary condition are performed numerically. Moreover, the effects of velocity slip at stretching sheet wall are also examined in this study. The highly nonlinear-coupled governing equations are converted to nonlinear ordinary differential equations via similarity transformations. The transformed governing equations are then solved numerically using the Keller box method and graphical results for velocity, temperature, and nanoparticle concentration as well as wall shear stress, heat, and mass transfer rate are achieved through MATLAB software. Numerical results for the wall shear stress and heat transfer rate are presented in tabular form and compared with previously published work. Comparison reveals that the results are in good agreement. Findings of this work demonstrate that Casson fluids are better to control the temperature and nanoparticle concentration as compared to Newtonian fluid when the sheet is stretched in a nonlinear way. Also, the presence of suspended nanoparticles effectively promotes the heat transfer mechanism in the base fluid.

1 November 2017 in Chemical Engineering Science
Verified
Journal Article
Closed access
IUImran Ullah
Imran Ullah
SSSharidan Shafie
Sharidan Shafie
OMOluwole Daniel Makinde
Oluwole Daniel Makinde
IKIlyas Khan
Ilyas Khan