R. Sivaraj

Bio: R. Sivaraj is an academic researcher from VIT University. The author has contributed to research in topics: Nanofluid & Stagnation point. The author has an hindex of 3, co-authored 6 publications receiving 23 citations.

Numerical simulation of blood nanofluid flow over three different geometries by means of gyrotactic microorganisms: Applications to the flow in a circulatory system:

Abstract: Biomedical engineers, medical scientists, and clinicians are expressing a notable interest in the measurement of blood flow rate because it is used to detect cardiovascular diseases such as atheros...

Exploring the heat transfer and entropy generation of Ag/Fe[Formula: see text]O[Formula: see text]-blood nanofluid flow in a porous tube: a collocation solution.

Abstract: Evaluating the entropy generation is essential in thermal systems to avoid the unnecessarily wasted thermal energy during the thermal processes. Nowadays, researchers are greatly fascinated to scrutinize the entropy generation in a human system because it is utilized as a thermodynamic approach to understand the heat transfer characteristics of cancer systems or wounded tissue and their accessibility status. Further, numerous nanoparticles have been employed as an agent to control the heat transfer of blood and wounded tissue. As a result, the present model manifests the entropy generation, flow characteristics and heat transport of Ag/Fe $$_3$$ O $$_4$$ -blood flow of a nanofluid in a permeable circular tube with the influence of variable electrical conductivity and linear radiation. Nonlinear transport equations are converted into ordinary differential equations by suitable similarity variables which are solved with weighted residual method. Significant parameters like Reynolds number, dimensionless permeability parameter, extending/contracting parameter, Eckert number and Hartmann number on the radial pressure, axial velocity, radial velocity and temperature are explored through graphs. The obtained results show that temperature distribution of Fe $$_3$$ O $$_4$$ nanoparticles is higher than Ag nanoparticle, in case of suction. The dimensionless permeability parameter has an opposite nature on the radial pressure for the suction and injection cases. Growing values of Hartmann number enhance the total entropy generation for the cases of suction and injection.

Impacts of temperature-dependent viscosity and variable Prandtl number on forced convective Falkner–Skan flow of Williamson nanofluid

Abstract: Fluid viscosity is considered as constant in several boundary layer analyses, but this fluid property can change remarkably when the temperature difference exists in the boundary layer. The Prandtl number and Schmidt number can also change significantly as the fluid viscosity changes depending on temperature. Therefore, this framework is exploring the consequences of varying viscosity and varying Prandtl number on Falkner–Skan flow of Williamson nanofluid over a wedge, plate and stagnation point. The Buongiorno nanofluid model has been employed to manifest the fluid transport properties of the Williamson nanofluid. Similarity transformations are utilized to transform the governing equations into ordinary differential equation and solved numerically using Runge–Kutta (RK) Fehlberg method. Williamson fluid velocity, temperature, concentration, skin friction factor, rate of heat transfer and rate of mass transfer are investigated with emerging parameters, and the outcomes are presented graphically. Computed results manifest that the Williamson nanofluid expresses the opposite nature in velocity and temperature for higher values of Weissenberg number parameter. Positive values of variable viscosity parameter diminish the significance of variable Prandtl number and variable Schmidt number in the boundary layer. Furthermore, it is noticed that the Williamson nanofluid temperature is higher over a plate compared with wedge and stagnation point cases.

Stability Analysis of Casson Nanofluid Flow over an Extending/Contracting Wedge and Stagnation Point

Abstract: This numerical study is conducted to scrutinize the dual solutions and stability analysis of the flow of Casson nanofluid past a permeable extending/contracting wedge and stagnation point. Momentum, heat and mass transfer behaviors of the Casson nanofluid have been modeled with the use of the Buongiorno nanofluid model. Suitable self-similarity variables are employed to convert the fluid transport equations into ordinary differential equations and the bvp4c MATLAB solver is used to solve the equations. The impacts of active parameters on fluid transport properties are illustrated graphically. The outcomes of the present analysis reveal that the influence of Casson fluid parameter on velocity and temperature distributions obtained from the first and second solutions exhibit the opposite natures. From the stability analysis, it is found that the thermophoresis and Brownian motion effects acquire the same critical point value on Nusselt number. The temperature distribution of the Casson nanofluid is higher over the wedge than stagnation point. The two solutions are found for the limited range of extending/contracting parameter. The detailed stability test is carried out to determine which of the two solutions is physically realizable and stable.

Entropy generation of tangent hyperbolic nanofluid flow over a circular cylinder in the presence of nonlinear Boussinesq approximation: a non-similar solution

Abstract: The analysis of entropy generation has received notable attention in the study of nanofluids because the prime objective of nanofluids is to admit high heat fluxes. The entropy production can be utilized to generate the entropy in any irreversible heat transfer process which is important in thermal machines. This work presents to explore the fluid transport characteristics and entropy generation of a tangent hyperbolic nanofluid over a horizontal circular cylinder with the influence of nonlinear Boussinesq approximation. The dimensionless nonlinear partial differential equations have been solved by using an implicit finite difference Keller box scheme. The impacts of active parameters on the flow field like Weissenberg number, power-law index, magnetic field, mixed convection, Brownian motion, thermal convention, thermophoresis and radiation are illustrated with graphs and tables. The current results exposed that the nanofluid velocity enhances for enhancing the mixed convection parameter. Isotherms thickness is escalated with increasing values of radiation parameter. Total entropy generation rises for higher values of dimensionless temperature ratio parameter.

Swimming of microbes in blood flow of nano-bioconvective Williamson fluid

Abstract: As blood flow patterns are employed in the diagnosis of circulatory disorders such as arteriosclerotic disease, bioengineers and medical scientists are interested in blood flow identification via the circulatory system. Researchers used non-Newtonian fluid models to measure blood flow cardiovascular system (e.g., hyperbolic tangent fluid, Powell Erying fluid, Casson fluid, Williamson fluid, etc.) as these fluids provide a rheological representation of blood with a more detailed thinning component. In this study, blood is taken as Williamson's fluid, and flow velocity is unsteady towards the stretching/shrinking surface in consonance with exothermic/endothermic function. The theology of gyrotactic microorganisms (GM) is addressed to nanofluid to stabilise nanoparticles due to bioconvection. A finite-difference computational approach evaluates the mathematical model followed by a stability and convergence analysis. The nanofluid blood velocity characteristics, temperature, concentration, and microorganisms are discussed following the diagrams. The skin friction, Nusselt number, Sherwood number and the microorganisms density are evaluated and clarified in detail. Besides, iso-concentrations and iso-microorganisms are configured for various factors to assess the nanofluid blood flows' boundary line thickness. The present analysis may be useful for many hyperthermia therapies, such as cancer treatment, tumour therapy and cardiac surgery, and applications in microbial fuel cells, microfluidic systems, and heat transfer contrivances.

Dynamics of water conveying SWCNT nanoparticles and swimming microorganisms over a Riga plate subject to heat source/sink

Abstract: Electromagnetohydrodynamic (EMHD) is very important because of its numerous advantages such as flow control in fluidics networks, fluid pumping, thermal reactors, mixing, fluid stirring, liquid chromatography, and micro coolers. Based on the above applications in this article discussed the electromagnetic forces on the SWCNT/water flow with microorganisms over a Riga plate subject to slip effects. In addition, the uniform heat source/sink effect is used in the energy equation, as well as the thermophoretic effect in the concentration equation. The governing nonlinear system of partial differential equations (PDEs) was reduced to ordinary differential equations (ODEs) by applying the appropriate similarity variables. Hence, Runge-Kutta-Fehlberg (RKF-45) method was applied to numerically solve the extremely nonlinear system. Based on the analysis of the results, it is worth concluding that raising the role of slip effects lowers the velocity, temperature, and concentration curves, while increasing the solid volume fraction increases the temperature, concentration, and motile microorganism density.

A numerical study of the ferromagnetic flow of Carreau nanofluid over a wedge, plate and stagnation point with a magnetic dipole

Abstract: Present communication mainly addresses the fluid transport characteristics of ferromagnetic Carreau nanofluid over a porous wedge, plate, and stagnation point with magnetic dipole effect for shear thinning/shear thickening cases. Suitable self-similarity variables are employed to convert the fluid transport equations into ordinary differential equations which are solved with the use of the Runge-Kutta-Fehlberg (RKF) approach. To check the accuracy of the present model, numerical results for various thermophoretic values for the cases of shear thinning/shear thickening, have been compared with the results obtained by using bvp4c (MATLAB) which divulges good agreement. Influence of active parameters like ferromagnetic-hydrodynamic interaction, thermophoretic, dimensionless distance, Brownian diffusion, suction/injection, Weissenberg number are graphically presented. Computed results manifest that shear thinning and shear thickening fluids express the opposite nature in fluid velocity and temperature for higher values of Weissenberg number. Among the wedge, plate and stagnation point of the plate, the magnitude of heat transfer over the plate is significant for increasing Ferromagnetic-hydrodynamic interaction parameter. Furthermore, it is noticed that higher values of suction/injection parameter decline the fluid temperature over a plate, wedge and stagnation point of a flat plate.