To improve the heat efficiency base fluids (water, engine oil, glycol), the interaction of nanoparticles (nanotubes, droplets, nanowires, metals and non-metals) into such traditional liquids is the most frequent mechanism and attained the researchers attention, especially in current decade. The nanofluid is a suspension of submerged solid particles in base fluids. The nano-materials convinced the applications in the field of nanotechnology, thermal engineering, industrial and bio-engineering. Following to such motivating applications in mind, current research reports the stagnation point flow of radiative micropolar nanofluid over an off centered rotating disk with applications of motile microorganisms. The novel dynamic of thermal radiation and activation energy are also incorporated. The appropriate transformations are utilized to reduce the partial differential equations into dimensionless forms. A numerical shooting scheme is used to obtain the approximate solution with MATLAB software. The effects of prominent parameter on velocity profile, nanofluid temperature, concentration of nanoparticles and microorganism profile are physically incorporated.

Applications of modified Darcy law and nonlinear thermal radiation in bioconvection flow of micropolar nanofluid over an off centered rotating disk

On the account of significance of bioconvection in biotechnology and several biological systems, valuable contributions have been performed by scientists in current decade. In current framework, a theoretical bioconvection model is constituted to examine the analyzed the thermally developed magnetized couple stress nanoparticles flow by involving narrative flow characteristics namely activation energy, chemical reaction and radiation features. The accelerated flow is organized on the periodically porous stretched configuration. The heat performances are evaluated via famous Buongiorno’s model which successfully reflects the important features of thermophoretic and Brownian motion. The composed fluid model is based on the governing equations of momentum, energy, nanoparticles concentration and motile microorganisms. The dimensionless problem has been solved analytically via homotopic procedure where the convergence of results is carefully examined. The interesting graphical description for the distribution of velocity, heat transfer of nanoparticles, concentration pattern and gyrotactic microorganism significance are presented with relevant physical significance. The variation in wall shear stress is also graphically underlined which shows an interesting periodic oscillation near the flow domain. The numerical interpretation for examining the heat mass and motile density transfer rate is presented in tubular form.

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Bioconvection flow in accelerated couple stress nanoparticles with activation energy: bio-fuel applications.

Abstract The evolution of compact density heat gadgets demands effective thermal transportation. The notion of nanofluid plays active role for this requirements. A comparative account for Maxwell nanofluids and Williamson nanofluid is analyzed. The bioconvection of self motive microorganisms, non Fourier heat flux and activation energy are new aspects of this study. This article elaborates the effects of viscous dissipation, Cattaneo–Christov diffusion for Maxwell and Williamson nanofluid transportation that occurs due to porous stretching sheet. The higher order non-linear partial differential equations are solved by using similarity transformations and a new set of ordinary differential equations is formed. For numerical purpose, Runge–Kutta method with shooting technique is applied. Matlab plateform is used for computational procedure. The graphs for various profiles .i.e. velocity, temperature, concentration and concentration of motile micro-organisms are revealed for specific non-dimensional parameters. It is observed that enhancing the magnetic parameter M , the velocity of fluid decreases but opposite behavior happens for temperature, concentration and motile density profile. Also the motile density profile decrease down for Pe and Lb . The skin friction coefficient is enhanced for both the Williamson and Maxwell fluid. 

https://www.nature.com/articles/s41598-021-04581-1.pdf

Exploring the magnetohydrodynamic stretched flow of Williamson Maxwell nanofluid through porous matrix over a permeated sheet with bioconvection and activation energy

Simultaneous features of Wu's slip, nonlinear thermal radiation and activation energy in unsteady bio-convective flow of Maxwell nanofluid configured by a stretching cylinder

\n Microorganism cells movement in the fluid is universal and affects many ecological and biological processes, including infection, reproduction, and marine life ecosystem. There are many biological and medical applications that require an understanding of the transport process in nanofluids containing a suspension of microorganism. The present problem deals with the bioconvection of Casson nanofluid containing a suspension of motile gyrotactic microorganisms over an inclined stretching sheet in the presence of thermal radiation, viscous dissipation, and chemical reaction and magnetic field. At the surface, the influence of the thermosolutal Marangoni convection and suction/injection impact are considered. The governing equations are solved numerically by using fourth-order Runge–Kutta–Fehlberg method with shooting technique. The impact of the major pertinent parameters on the velocity, temperature, nanoparticles concentration, and density of the motile microorganism is illustrated graphically. Finally, the correlations of various crucial parameters on skin friction, local Nusselt number, Sherwood number, and local motile microorganism density number are displayed through the graphs and tables.

Thermosolutal Marangoni Impact on Bioconvection in Suspension of Gyrotactic Microorganisms Over an Inclined Stretching Sheet

This paper investigates the generalized Zakharov–Kuznetsov (GZK) equation and generalized modified Zakharov–Kuznetsov equation in the presence of external periodic forcing term together with damping. An approximate analytical solution is obtained by employing the direct assumption technique. The framework staged here reveals number of beautiful wave features such as positive amplitude soliton, rare effective soliton, periodic rational soliton, kink type soliton, etc. Moreover, two new parameters along with a control function is introduced to extend the study of traveling wave solution and to create new types of solitary wave solution that are depicted from a numerical standpoint. It is noticed that the generalized wave solution for GZK in presence of external periodic forcing with a damping, positive potential soliton may transform into a rare effective soliton due to an increase in the nonlinearity of the system.

Approximate Analytical Solutions of Generalized Zakharov–Kuznetsov and Generalized Modified Zakharov–Kuznetsov Equations

http://amcm.pcz.pl/get.php?article=2021_2/art_06.pdf

Studies on the effect of kinematic viscosity on electron-acoustic cylindrical and spherical solitary waves in a plasma with trapped electrons

This article explores progressive solitary solution and shock solution for the dust–ion-acoustic waves (DIAWs) propagating in a collisional unmagnetized dusty plasma containing dust grains with negative dust charge, positive ions, neutral particles and Maxwellian electrons. In an earlier literature, Gao et al. in Braz. J. Phys. (2019) derived nonplanar KdV–Burgers (NKDVB) equation from the basic field equation utilizing reductive perturbation method (RPT). Further, assuming that conservation law holds in the system they obtained an approximate solitary wave solution, although the presence of Burgers term causes increase of the effect from viscosity and opposes the conservation law in the system. In that case, shock is wave usually generated due to the effect of strong anomalous dissipation. Being aware of the facts, simplified Hirota bilinear method is employed and shock-type wave solution is obtained. Again, if dissipation is weak, the balance between the dispersion and nonlinearity may lead to form solitary solution. Considering the case of weak dissipation, solitary wave solution is directly explored (without assuming conservation law) by applying a weighted residual method. Some 2D and 3D graphs are depicted to analyze the propagating behavior of nonplanar waves in different parametric spaces.

Subrata Roy

Papers

Thermosolutal Marangoni Impact on Bioconvection in Suspension of Gyrotactic Microorganisms Over an Inclined Stretching Sheet

Approximate Analytical Solutions of Generalized Zakharov–Kuznetsov and Generalized Modified Zakharov–Kuznetsov Equations

Studies on the effect of kinematic viscosity on electron-acoustic cylindrical and spherical solitary waves in a plasma with trapped electrons

Cylindrical and Spherical Dust–Ion-Acoustic Shock Solitary Waves by Korteweg–de Vries–Burgers Equation