*4.4. Prandtl Number Effects*

Figure 8 shows how different values of the Prandtl number, *Pr*, affect the temperature and concentration distribution. As can be seen in Figure 8, increasing the *Pr* lowers the temperature and concentration. *Pr* is calculated by the amount of momentum to thermal diffusion. As the *Pr* rises, thermal and mass diffusion decreases, resulting in a smaller TBL and CBL, as it turned out to reduce *θ*(*η*) and *φ*(*η*).

**Figure 8.** Influence of the Prandtl number on *θ*(*η*) and *φ*(*η*).

*4.5. Thermophoresis and Brownian Motion Parameter Effects*

From Figure 9, we can see the behavior of *Nt* on *θ*(*η*) and *φ*(*η*). As is evident in the figure, *θ*(*η*) and *φ*(*η*) are both increased for *Nt*. Logically, *Nt* determines the intensity of the TBL and CBL. When *Nt* rises, the particles begin to move faster, leading to increased kinetic energy within the flow domain; this leads to a rise in *θ*(*η*) and TBL thickness. Similarly, a marginal change in *Nt* causes *φ*(*η*) to significantly enhance.

**Figure 9.** Influence of the thermophoresis parameter on *θ*(*η*) and *φ*(*η*).

The change in the *Nt* causes the fluid particles to move quickly, releasing surplus thermal energy and causing a rise in CBL thickness. As a result, *φ*(*η*), demonstrated in Figure 10, shows a significant increase. The temperature gradient is significantly affected by the Brownian motion parameter *Nb*. When *Nb* grows, it produces an increase in *θ*(*η*), which promotes the TBL thickness. Upgrading *Nb* causes faster fluid particle movement, and, as a result, a rise in *θ*(*η*) and TBL thickness is noted, as can be seen in Figure 10. As mentioned earlier, speeding up the particle movement diminishes the concentration gradient; the particles begin to migrate quickly from regions of greater to lower concentration when the mobility of the fluid particles upsurges, with an upsurge in *Nb*. Thus, an increase in *Nb* causes a drop in *φ*(*η*), as shown in Figure 10.

**Figure 10.** Influence of the Brownian motion parameter on *θ*(*η*) and *φ*(*η*).
