Search

The improved thermal assessment of nano‐particles in presence of magnetic force, thermal radiation and activation energy involve dynamic applications in thermal engineering, industrial processes, and modern technologies. The bioconvection pattern in various nanoparticles attributes novel bio‐technology applications like bio‐fuels petroleum engineering, enzymes, bio‐sensors, and many more. On this end, present theoretical analysis endeavors to examine the thermal characteristics of time dependent Williamson nanofluid confined by an unsteady stretched radioactive Riga plate. Here, nanofluid bioconvection is developed by the combined aspects of buoyancy forces and magnetic field with collaboration of motile microorganisms and nanoparticles. Present analysis is further carried out in presence of activation energy, nonlinear thermal radiation and chemical reaction. The whole exploration is exposed to convective Nield constraints on boundary. The dimensionless form of formulated nonlinear system is achieved with utilization of apposite transformations and then approximate solution is elucidated by shooting technique. The graphical interpretation for numerous relevant parameters on velocity, concentration, temperature and motile microorganism profiles are displayed. The results reveal that an increasing variation in velocity is noticed with modified Hartmann. An increasing nanofluid temperature is associated with Williamson parameter and temperature ratio constant. Moreover, the motile microorganism distribution enhances with bioconvected Lewis and mixed convection constant. [ABSTRACT FROM AUTHOR]

Recently, nanoengineering has evolved to utilize nanoparticles along with base liquids to enhance the thermal attributes of pure liquids. The industry today also highly relies upon thermal machine performances, and the use of nanomaterials is the key to serve this purpose. In this research, the applications of the slip phenomenon are addressed for bioconvection applications in a non-Newtonian "Eyring–Powell" nanofluid model confined by a stretching sheet. The activation energy and nonlinear thermal radiation are taken as novel impacts during the study. The flow has been saturated by Darcy–Forchheimer porous space. The fundamental laws are attributed to formulate the governing expressions. The numerical simulations are continued employing a shooting scheme to obtain the solutions. The executive and novel physical importance of parameters that governs the flow is addressed for nanofluid velocity, temperature, concentration, and microorganisms' profiles. The observations reveal that presence of slip parameter control the velocity but improve the heat and mass transportation phenomenon. The nanoparticles concentration increases with inertial forces and activation energy. Moreover, the bioconvection Lewis number declines the microorganism profile while increasing trend is noted for higher values of slip parameter. [ABSTRACT FROM AUTHOR]

The ultra-high significances of thermal radiation, magnetic field and activation energy in thermal enhancement processes allow significant applications in chemical and mechanical engineering, modern technology and various thermal engineering eras. The improvement in energy resources and production became one of the major challenges for researchers and scientists for sustained development in industrial growths. Beside this, the bioconvection assessment in nanomaterials conveys prestigious applications in biotechnology like bio-sensors, enzymes, petroleum industry, bio-fuels and many more. In view of such renewable applications, present exploration discloses unsteady two-dimensional flow of third-grade nanomaterial accommodating gyrotactic microorganisms induced by unsteady stretched Riga sheet in porous medium. The formulated flow problem is further scrutinized by utilizing the chemical reaction, activation energy, thermal radiation and magnetic aspects. The convective Nield constraints are further subjected in the current investigation. Apposite transformations are used to condense the nonlinear developed problem into dimensionless ordinary form. The numerical solution of such similar flow problem is presented via shooting technique. The detailed graphical illustrations of the dimensionless temperature, nanoparticles concentration, velocity and motile microorganisms for physical significance of diverse relevant parameters are deliberated. Furthermore, numerical data of local Sherwood, Nusselt and motile density numbers is designated in tabular form. Study accentuated that velocity increases for higher modified Hartmann and material constants, while the effects of buoyancy ratio and bioconvected Rayleigh numbers are rather opposite. The temperature, microorganism and concentration distributions were enhanced for unsteady parameter. It is also acknowledged that the concentration distribution is enhanced for activating the energy number. Moreover, the microorganism distribution enhances for concentration difference and magneto-porous constants, while bioconvected Lewis and Peclet numbers show conflicting trend. [ABSTRACT FROM AUTHOR]

In the era of nano-engineering, the decomposition of nanoparticles with base liquids enhances the thermal performances of such base materials. Owing to the tremendous demand for high thermal performances in industries, the use of nanoparticles becomes more fascinating. In most nanofluid analyses, the thermal inspection of non-Newtonian is based on the assumption of constant viscosity. However, considering viscosity as a function of temperature is more beneficial to improve the transportation of mass and heat transfer phenomenon. This theoretical analysis addresses the narrative role of partial slip and temperature-dependent viscosity in the bioconvection assessment of Maxwell nanofluid confined by a stretched surface. The nonlinear thermal radiation and activation energy applications are encounter as a novel impact. The formulated set of coupled and nonlinear flow problems is numerically presented with proper execution of shooting algorithm. The comparative task for verifications is done against previous investigations with excellent confirmation claim. The graphical exploration because of flow parameters is reported for the nanofluid velocity, temperature, concentration, and microorganisms. The observations are summarized in the conclusion part. [ABSTRACT FROM AUTHOR]

Here theoretical analysis of heat, mass and motile microorganisms transfer rates in Casson fluid flow over stretched permeable surface of cylinder is studied. Investigated is carried out in the presence of suspended nanoparticles and self-propelled gyrotactic microorganisms. The effects of buoyancy forces, magnetic field and thermal radiation are considered. The nanoparticles with suitable suspension are stabilized through mutual effects of buoyancy forces and bioconvection. Furthermore, activation energy and Darcy- Forchheimer effects on bio nanofluid flow are accounted. The constitutive theories are executed to develop the model formulation. The obtained model is made dimensionless trough appropriate transformations. The dimensionless flow model is tackled by built-in algorithm of shooting technique. Impact of flow controlling constraints parameters is physically elaborated by making graphical illustrations. The outcomes based on numerical data against essential engineering formulations like surface drag force, Nusselt, density and Sherwood numbers are tabulated. Main outcomes are successfully summarized in terms of closing remarks. [ABSTRACT FROM AUTHOR]

Owing to the growing interest of bioconvection flow of nanomaterials, many investigations on this topic have been performed, especially in this decade. The bioconvection flow of nanofluid includes some novel significance in era of biotechnology and bio-engineering like bio-fuels, microbial enhanced oil recovery, enzymes, pharmaceutical applications, petroleum engineering, etc. The current analysis aims to explore the various thermal properties of Sutterby nanofluid over rotating and stretchable disks with external consequences of variable thermal conductivity, heat absorption/generation consequences, activation energy and thermal radiation. The considered flow problem is changed into dimensionless form with convenient variables. The numerical structure for the obtained non-dimensional equations is numerically accessed with built-in shooting technique. The consequences of various physical parameters are observed for enhancement of velocity, temperature, concentration and motile microorganism. It is noted that both axial and tangential velocity components decrease with Reynolds number and buoyancy ratio parameter. The nanofluid concentration improves with activation energy and concentration Biot number. Moreover, an improved microorganisms profile is noticed with microorganism Biot number and bioconvection Rayleigh number. [ABSTRACT FROM AUTHOR]

The present work focuses on the numerical investigations of the existence of oxytactic microorganisms on the bioconvection flow of nano-encapsulated phase change material (NEPCM) inside an annulus. The novel geometry of an annulus contains an inner wavy cylinder and an outer circular cylinder considering a rotational circular velocity of an inner wavy cylinder. The incompressible smoothed particle hydrodynamics (ISPH) method solved the dimensionless form of controlling equations. The novel annulus between the embedded circular cylinder and the outer circular cylinder can be applied in the tube bundles in heat exchangers. Further, rotation of an inner wavy cylinder in a circular cavity can be used in thermal fin's vibration and cooling of the electric devices. The effects of pertinent parameters such as a rotational frequency number ω , bioconvection Rayleigh number Ra b , thermal radiation Rd , Lewis number Le , and Hartmann number Ha on the contours of oxygen concentration ϕ , temperature θ , heat capacity ratio Cr , oxytactic microorganisms N , and velocity field V as well as the average Nusselt & Sherwood numbers Nu ¯ and Sh ¯ are conducted. Increasing ω enhances the maximum of V by 56.6% and lowers Nu ¯. The variations of Ra b are enhanced the contours of N and maximized the velocity field from 0.86 at Ra b = 1 to 8.22 at Ra b = 100 due to the power in bioconvection flow. Increasing Le diminishes the strength of oxygen concentration ϕ and microorganisms N. Increasing Ha from 0 to 50 slows down the velocity field's maximum by 47.2 % and enhances the value of Nu ¯. [ABSTRACT FROM AUTHOR]

A three-dimensional (3-D) investigation of micropolar nanofluid has been presented under the novel impact of nonlinear thermal radiation, activation energy and magnetohydrodynamic features. The induced flow is reflected by a rotating disk which rotates with uniform velocity along z -directions. The fundamental features of Brownian diffusion and thermophoretic assessment is determined by following Buongiorno's nanofluid model. The nanofluid contains gyrotactic microorganisms for which bioconvection pattern is examined for stability assessment. The model flow problem under the certain flow assumptions are retained into the set of dimensionless eqs. A numerical procedure is employed to achieve the solution of such equations. The prime features of parameters against velocity, temperature, concentration and microorganism profiles are graphically examined with justified physical consequences. The numerical computations for wall shear stress, effective local Nusselt number, local Sherwood number and local motile density number are elaborated in terms of numerical data. The simulated theoretical results yield dynamic applications in era of thermal engineering and bio-technology area [ABSTRACT FROM AUTHOR]

The aim of current attempt is to visualize the flow of ('modified') second-grade nanofluid with heat, motile microorganisms and mass transfer rates over stretching surface. The modified second grade fluid is utilized to analyze the rheological behavior. The energy equation is modified with presence of heat absorption and generation effects. In order to stabilize the suspension of nanoparticles, the concept of microorganisms has been introduced. Further present flow analysis is performed with Nield boundary conditions. The formulated equations are first reduced in to dimensionless form by using similarity variables. The approximate solution of these locally similar nonlinear ordinary differential equations is calculated by using shooting method through computational software MATLAB. The calculated results are carefully compared with earlier studies and found an excellent agreement. The ascendancy of interesting parameters like generalized second-grade parameter Brownian motion, thermophoresis effects, Peclet number are examined for multiple values of power law index. It is found that velocity profile declined effectively by buoyancy ratio parameter and bioconvection Rayleigh number. The temperature and concentration profiles enhanced with thermophoretic parameter. It is further observed that motile microorganism profile depressed with Brownian movement parameter and Prandtl number. A prominent demising temperature profile has been noted for shear thickening case as compared to shear thinning. • Modified second-grade nanofluid with motile microorganisms is studied. • Present flow analysis is performed with Nield boundary conditions. • The flow is considered over a stretching surface in two-dimensional channel. • MATLAB software is used to execute the numerical shooting algorithm. • A numerical comparison is also presented for the governing parameters. [ABSTRACT FROM AUTHOR]

On account of fabrication of nano bio-materials applications in various industrial and technological manufacturing systems, bioconvection in nanofluid has become famous in recent years. This investigation is made by adopting bioconvected flow of Oldroyd-B nanofluid over stretched sheet which assumed to be oscillatory. The periodically moving sheet generates the flow. The thermal radiations effects are also encountered in the energy equation. Three independent variables governed by the flow equations are diminished into two independent variables. The series solution for transformed ordinary differential equations is calculated by homotopy analysis method. In present investigation, thermal radiation for linearized Rosseland's assumption is studied in one parametric approach instead of two parametric approaches. Here, the temperature profile does not depend upon Prandtl number and radiation parameter but combination of these two which is termed as effective Prandtl number. Significance of flow parameters on effective local Nusselt number, local Sherwood number and local motile density number is evaluated in tabular form. It is noted that the temperature of nanoparticles effectively enhanced by increasing buoyancy ratio and Rayleigh number. The concentration profile increases with buoyancy ratio and bioconvected Rayleigh number. The higher values of bio-convected Peclet number lead to be decrement of motile microorganism profile. The results presented here can play effective role for enhancement of efficiency of heat transfer devices and microbial fuel cells. • Bioconvected flow of Oldroyd-B nanofluid over stretched sheet is considered. • The periodically moving sheet generates the flow. • The thermal radiations effects are also encountered in the energy equation. • Local Nusselt number, local Sherwood number and local motile density number are evaluated in tabular form. [ABSTRACT FROM AUTHOR]