**4. Results and Discussion**

This section explains the impact of flow on suction/injection permeable Reynolds number *Re*, contraction/expansion ratio parameter α, volume friction parameters *ϕs*<sup>1</sup> and *ϕs*2, magnetic parameter *M*, nanolayer thickness parameter *h*, Schmidt number *Sc*, exothermic/endothermic parameter λ, and dimensionless parameter *n* on the velocity, temperature, and concentration profiles (Figures 2–6). Figure 2 was plotted to show the effect of *M* on velocity profile *f* . It is shown that with a rising magnetic parameter velocity, the *f* component decreased. This is because by enhancing the magnetic value, Lorentz forces are produced, decreasing the axial momentum of fluid particles. We can conclude from this argument that transverse application of the magnetic field normalizes fluid velocity. The effect of *E* on the mass concentration profile is shown in Figure 3. It is noticed that the mass concentration profile decreased as the augmented value of the dimensionless activation energy parameter increased. The influence of nanolayer thickness on temperature is investigated and recorded in Figure 4. It is observed that the temperature decreased at the lower plate and increased at the upper plate when the value of the nanolayer thickness parameter was increased. Figure 5 depicts the influence of the volume fraction parameter on the temperature profile. It can be seen that the enhancement in volume fraction reduced the temperature in the interval −1 < *η* < 0 and increased in the interval 0 < *η* < 1. Figure 6 shows a comparison graph of effective thermal conductivity and noneffective thermal conductivity, increase in the values of volume fraction *ϕs*<sup>1</sup> and *ϕs*2; the effective thermal conductivity of hybrid nanofluids has a high heat transfer rate as compared to the non-effusive thermal conductivity of nanofluids. The reason is that noneffective thermal conductivity does not include the influence of the radius of particles and nanolayer thickness. Table 3 represents the variation in shear stress (*f*(−1)). Physically, shear stress (*f*(−1)) develops on the boundary of any real fluid flowing over a solid, along with liquids. According to the no-slip requirement, the float velocity has to be identical to the fluid velocity at a few stops from the boundary, even though the float velocity on the boundary has to be zero. The boundary layer is the location that lies between those spots. The shear pressure is inversely correlated with the fluid's stress rate for all Newtonian fluids in laminar float, with viscosity serving as the proportionality constant. At the bottom plate, the heat transfer rate (*θ* (−1)) and the mass transfer rate (*X* (−1)) for the suction and injection instances were calculated. The flow of thermal energy between physical systems is known as heat transfer (*θ* (−1)). The rate of heat transfer (*θ* (−1)) is determined by the temperatures of the systems and the quality of the intervening medium. The mass transfer (*X* (−1)) is a physical event that involves the observation of the net movement of generic particles from one point to another. For suction, *Re* is less than zero. Suction occurs when inertia is smaller than viscosity. It was noticed that as the value of the expansion/contraction ratio parameter moved from negative to positive, it decreased the shear stress, heat, and mass transfer rate. The enhancement in the heat and mass transfer rates was noticed when the activation energy parameter was increased. It was observed that the heat transfer rate increased with the augmented values of nanolayer thickness. The Prandtl number and nanolayer thickness were opposite to the Nusselt number. The reason is that the Prandtl number is the product of diffusive momentum and the inverse of thermal diffusivity. Increasing the Prandtl number, diffusivity increases together with momentum, while the coefficient of heat flux decreases. The heat transfer rate decreases due to an increase in exothermic and endothermic parameters. It was observed that the mass transfer rate decreased with the augmented values of *n*. For injection *Re* > 0 cases, injection occurred when inertia was greater than viscosity. It was observed that the effect of nanolayer thickness *h* and the Prandtl number had opposite impacts in both suction and injection cases on the heat transfer rate and *α*, *E*, *λ*, *ϕs*1, *ϕs*2, and *n* had the same impact in both suction and injection cases on shear stress (*f*(−1)), (*θ* (−1)) and mass transfer rate (*X* (−1)).

**Figure 2.** Effect of the magnetic parameter on velocity *f* .

**Figure 3.** Effect of activation energy on mass concentration.

**Figure 4.** Effect of nanolayer thickness on the temperature profile.

**Figure 5.** Effect of volume fraction on temperature.

**Figure 6.** Effect of thermal conductivity and effective thermal conductivity.

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**Table 3.** Variation in shear stress, heat, and mass transfer rate for suction and injection cases at the lower plate.
