A hybrid method for particle image velocimetry (PIV) is developed to overcome the limitations of the optical flow method applied to PIV images with large displacements. The main elements of the hybrid method include a cross-correlation scheme for initial estimation, a shifting scheme for generating a shifted image, and an optical flow scheme for obtaining a refined high-resolution velocity field. In addition, a preprocessing scheme is used for correcting the illumination intensity change. The accuracy of the hybrid method is evaluated through simulations in a parametric space in comparison with the typical correlation methods and optical flow method. Further quantitative comparisons are made in PIV measurements in a circular air jet.

This exploration aims to study the comparison of heat transfer capabilities of two nanofluid oblique, steady stagnation-point flow combinations comprising single-walled carbon/water (SWCNHs/water) and multiwalled carbon nanotube/water (MWCNTs/water) toward a stretching surface influenced by nonlinear thermal radiation employing the Xue model. This envisaged comparison model is inimitable and still scarce in the literature. Relying on the Tiwari–Das nanofluid model, a mathematical framework is constructed. The system of partial differential equations is converted using suitable transformations into an ordinary differential system of three equations, which is evaluated numerically using the bvp4c method. The physical behavior of significant parameters and their graphical representation are thoroughly examined. The results show that the SWCNHs/water nanofluid outperforms the MWCNTs/water nanofluid. It is further witnessed that SWCNH nanoparticle contained nanofluid has considerably greater thermal radiation than MWCNT nanoparticles. The envisaged model is also validated by comparing it with a published study.

The main objective of the present study is to explore the effects of electromagnetohydrodynamics electroosmotic flow of hybrid nanofluid through circular cylindrical microchannels. An analysis of hybrid nanofluid consisting of four different nanomaterials i.e., single and multiwall carbon nanotubes, silver, and copper is carried out. Yamada–Ota model is employed for the single and multi wall carbon nanotubes, whereas, Xue model is used for the Silver and Copper hybrid nanofluid for specifying the thermal conductivity. The imposed pressure gradient, electromagnetic field and electroosmosis actuated the fluid flow. The flow of heat transfer and Nusselt number with the account of various effects of Joule heating and viscous dissipation under the circumstances of constant heat flux are discussed graphically. The governing system of equations is molded into a system of coupled, nonlinear ordinary differential equations. The shooting technique is used to extract the numerical solutions of the converted system of equations. Also, the outturn of different parameters like Hartman number, the strength of lateral direction electric field, EDL (electric double layer) electrokinetic width, Joule heating parameters on the temperature, and velocity are investigated. The conversion of simple fluid to hybrid nanofluid has greatly alteration in the present model. It has enhanced the thermal properties of fluid. It is also noted that $$SWCNT-MWCNT$$ S W C N T - M W C N T based hybrid nanofluid has most influential impact on Nusselt number, temperature distribution and velocity of the fluid. This attempt is useful for the designing of effectual electromagnetic appliances and exquisite.

The nanofluid flows play a vital role in many engineering processes owing to their notable industrial usage and excessive heat transfer abilities. Lately, an advanced form of nanofluids namely “hybrid nanofluids” has swapped the usual nanofluid flows to further augment the heat transfer capabilities. The objective of this envisaged model is to compare the performance of two renowned hybrid nanofluid models namely Hamilton–Crosser and Yamada–Ota. The hybrid nanoliquid (TiO2-SiC/DO) flow model is comprised of Titanium oxide (TiO2) and Silicon carbide (SiC) nanoparticles submerged into Diathermic oil (DO). The subject flow is considered over a stretched surface and is influenced by the magnetic dipole. The uniqueness of the fluid model is augmented by considering the modified Fourier law instead of the traditional Fourier law and slip conditions at the boundary. By applying the suitable similarity transformations, the system of ordinary differential equations obtained from the leading partial differential equations is handled by the MATLAB solver bvp4c package to determine the numerical solution. It is divulged that the Yamada–Ota model performs considerably better than the Hamilton–Crosser flow model as far as heat transfer capabilities are concerned. Further, the velocity reduces on increasing hydrodynamic interaction and slip parameters. It is also noted that both temperature profiles increase for higher hydrodynamic interaction and viscous dissipation parameters. The envisioned model is authenticated when compared with an already published result in a limiting case.

Solar thermal systems have low efficiency due to the working fluid's weak thermophysical characteristics. Thermo-physical characteristics of base fluid depend on particle concentration, diameter, and shapes. To assess a nanofluid's thermal performance in a solar collector, it is important to first understand the thermophysical changes that occur when nanoparticles are introduced to the base fluid. The aim of this study is, therefore, to analyze the hydrodynamic and heat characteristics of two different water-based hybrid nanofluids (used as a solar energy absorber) with varied particle shapes in a porous medium. As the heat transfer surface is exposed to the surrounding environment, the convective boundary condition is employed. Additionally, the flow of nanoliquid between two plates (in parallel) is observed influenced by velocity slip, non-uniform heat source-sink, linear thermal radiation. To make two targeted hybrid nanofluids, graphene is added as a cylindrical particle to water to make a nanofluid, and then silver is added as a platelet particle to the graphene/water nanofluid. For the second hybrid nanofluid, CuO spherical shape particles are introduced to the graphene/water nanofluid. The entropy of the system is also assessed. The Tiwari-Das nanofluid model is used. The translated mathematical formulations are then solved numerically. The physical and graphical behavior of significant parameters is studied.

There are various implementations of common fluids in industrial and chemical processes. With the cooperation of the nanoparticles, the lower thermal properties of such fluids can be augmented. By using a new kind of nanofluid namely hybrid nanofluid, the heat transfer rate of such fluids can be boosted more quickly. The main intention of this research is on entropy analysis in the stagnant point flow of a hybrid nanofluid. The mixed convection nonlinear thermal radiative flow on a stretchable vertical sheet is examined under the influences of the induced magnetic field and chemical reactions. The impacts of Joule heating, partial slips and viscous dissipation are also involved. After the execution of the appropriate similarity transformations, the constituting equations of the flow problem emerge as the nonlinear dimensionless setup of ordinary differential equations. An amplification is examined in the velocity field, entropy generation, and induced magnetic field relative to the mixed convection parameter. With the improved Brinkman number, an augmentation is developed in the entropy of the system. Moreover, both the heat transfer rate and the surface drag force exhibit an accelerating behavior relative to the mixed convection parameter.

The current communication is designed by keeping in the mind high heat transfer capabilities of nanoliquids with the dispersion of diversified-natured nanoparticles in poorly conducting base liquids. Here, an amalgamation of metallic (Cu) and hybridization of metallic and non-metallic oxide (Cu-TiO2) nanoparticles to uplift thermophysical attributes of water is deliberated. The magnetically affected flow between rotating disks under the impact and permeability aspect is assumed. Empirical relations for effective dynamic viscosity, density, and heat capacitance to show mesmerizing features of obliged nanoparticles are also expressed. In addition, mathematical relations also depend on morphological factors like shape, size, and diameter of inducted nanoparticles. The mathematical formulation of the problem is conceded in the form of a system of ODEs after using similarity transformation on dimensional PDEs. Simulations of the complex coupled differential structure are solved by using a numerical approach by employing shooting and Runge–Kutta procedures jointly. The impact of flow concerning variables on associated distributions is revealed through tabular and graphical manner. Quantities of engineering interest associated with work like wall friction and thermal flux coefficients at walls of the disk are also calculated. It is deduced from an examination that the addition of metallic particles raises heat transfer more than non-metallic particles. A significant impression of magnetic field on shear stress is executed by hybrid nanoparticles along the surface of disks. In addition, elevation in Nusselt number and depreciation in skin friction coefficient is revealed against increasing magnitude of nanoparticle volume fraction. A positive trend in skin friction coefficient is manifested against the increasing magnitude of Reynold number. It is also observed that by increasing the size and shape of hybrid nanoparticles thermal conductivity and viscosity of the base fluid increases.

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