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Hybrid nanofluids can be designed to exhibit multiple functionalities, such as improved thermal conductivity, electrical conductivity, and magnetic properties. Magnetic hybrid nanofluids are gaining recognition in various mainstream applications, including heat transfer, solar systems, acoustic applications, and more. Further, hybrid nanofluids improve the thermal efficiency of radiators, efficiency of heating, ventilation, and air conditioning systems and drug delivery systems. Their notable advantage lies in their capacity to enhance the thermophysical properties of the constituent particles. Peristalsis of MHD hybrid nanomaterial $({\mathrm{\text{Al}}}_2{\mathrm{\text{O}}}_3-{\mathrm{\text{TiO}}}_2+\mathrm{\text{water}})$ in symmetric channel is emphasized. Darcy–Forchheimer law explores nonlinear nature of porous media. Effects of Joule heating and viscous dissipation are considered. The viscosity of fluid depends on temperature. The dimensionless system after invoking lubrication approach is analyzed numerically. Characteristics of prominent variables on the quantities under interest are examined. Comparative analysis of heat transfer rate of hybrid nanofluid and nanofluid are also discussed in detail. Heat transfer rate of system increases by increasing the quantity of nanomaterial in the fluid. Therefore, the temperature of the fluid decreases and the efficiency of the system increases.

CVFEM usage for modeling of nanomaterial flow style in a permeable elliptical tank including Lorentz effect was scrutinized in the current research. Hybrid material with use of homogeneous model was applied and radiation term has been involved in governing equations. Outputs have been depicted in contours and plots. In addition, a new formula for Nu was reported. Augment of Nu by considering greater permeability can be explained by stronger temperature gradient in cases with higher Da. Nanomaterial flow becomes suppressed with augment of Ha which results in lower Nu. As Ha was augmented from 0 to 20, 18% reduction was reported in Nu. Permeability has favorable influence on nanomaterial flow and the impact of Ha is the opposite of permeability.

To decrease the exergy drop, a new style of tape with an inset of the obstacle has been applied in the current utilized heat exchanger. Numerical technique was chosen to discover the solution of the equations for the current application. Hybrid nanopowders were added into a base fluid and an experimental formulation was utilized for involving the new working fluid. Addition of nanopowder and insertion of obstacle over the tape lead to augmentation of productivity of unit and help the system to minimize the irreversibility. Checking the correctness of the procedure in the modeling has been tested and proved to be in nice agreement. Two configurations for geometry of tube have been compared in two levels of Re. The regime of fluid is turbulent and the generation of grid has been done with considering the limitation of $Y^{+}$. With the insertion of obstacle in the lowest level of Re, the swirl flow increases and $S_{\mathrm{\text{gen}},f}$ augments about 252.6% while $S_{\mathrm{\text{gen}},h}$ reduces about 21.22%. The value of heating term is much higher than the friction term, so Xd declines by 21.21%. With the use of new configuration of turbulator, elevating $V_{\mathrm{\text{in}}}$ leads to elevation of $S_{\mathrm{\text{gen}},f}$ by 24.21% but $S_{\mathrm{\text{gen}},h}$ declines about 83.39%. Adding the turbulator with obstacle, $T_w$ decreases about 0.22% when Re $=$ 2e4.

A mathematical theory was developed to simulate how magnetic force causes hybrid nanopowder to move through space. This numerical approach was created by combining the FEM and FVM, and triangular elements were used to create the grid. Iron oxide and MWCNT mixture were dispersed in water, and the hybrid nanomaterial’s properties were assessed using earlier empirical formulas. Gravity force can participate in the phenomena because there is a hot, wavy wall on the bottom side. Radiation flux impact was added, and different permeability spaces were used. A counterclockwise eddy is formed inside the domain as an output of gravity force and with the increase of Da, it divides into two vortexes. Additionally, increasing Da causes about a 75% increase in eddy power and increases iso-temperature distortions. The velocity decreases by between 82.5% and 90% as Lorentz terms are considered for flow equations, depending on the amount of Da. When Ra is taken into account at $\mathrm{\text{Da}}=10-2$, $\mathrm{\text{Ha}}=60$, Nu increases by about 27.75%. When $\mathrm{\text{Ha}}=0$, Nu increases by about 10.59% as permeability increases. With the use of MHD, Nu decreases by 43.26% when Ra and permeability are at their highest points.

To examine the hybrid nanomaterial transportation within a permeable region, a numerical approach was applied. The permeable domain was filled with a mixture of water with hybrid nanomaterial (Fe₃O${}_4+$ MWCNT). The wavy below wall experiences uniform flux but the top circular wall maintains at cold temperature. Magnetic field in $x$-direction was applied and non-Darcy formulation was applied for applying permeability effect. Gravity forces help the transportation of hybrid nanomaterial and magnetic forces reduce the speed of nanomaterial. Imposing nanomaterial can decline the irreversibility. For simulation of equations, CVFEM was applied and Bejan and Nu numbers were calculated. Verification test depicts the nice agreement and contours for irreversibility have been presented. By imposing Ha, the Be augments about 4.36% while Nu declines around 13.32%. By selecting greater Da, the Nu intensifies around 8.95% while Be declines about 4.35%. Nu elevates around 93.78% with an augment of Ra while Be drops around 52.75%.

Hybrid nanomaterial exergy drop and thermal manners were examined in this work with involving the porous media in middle part of the pipe. Moreover, to augment the rotational velocity, disturber device was applied in test section. The two sections near the entrance and outlet were in absence of disturber and porous zone because of importance of shun of backflow and reach of fully developed condition. Laminar flow with assume of homogeneous mixture for hybrid nanomaterial (Al₂O${}_3+\mathrm{\text{MWCNT}}$ and water) results in final model with involving the non-Darcy approach for permeable media. Finite volume approach was applied for achieving the outputs which are exergy loss (Xd) and hydrothermal behavior. Use of additives results in lower Xd more than 7.7% when $\mathrm{\text{Re}}=10\mathrm{\text{Da}}=\mathrm{\text{1e2}}$. With growth of Re, the Xd declines around a bit greater than 19%. Utilizing higher permeability allows the hybrid nanofluid moves quicker and exergy loss augments less than 10.5%.

The solvent-free hybrid nanomaterial consisting of multiwall carbon nanotubes (MWNTs) and silica nanoparticles are prepared by a facile route. The content of MWNTs/silica nanoparticles is up to 20 wt.%. The hybrid nanomaterial exhibits liquid-like behavior in the absence of solvent at room temperature.