*4.2. Temperature Profile*

Figure 14 shows the effect of Reynolds number *Re* on heat transfer. The larger values of *Re* increase the temperature of ZnO-C2H6O<sup>2</sup> and Au-ZnO/C2H6O2. It has been observed in Figure 15 that as the stretching parameter *k*<sup>6</sup> increases, the temperature of ZnO-C2H6O<sup>2</sup> and Au-ZnO/C2H6O<sup>2</sup> increase. These observations indicate that the fluid temperature and its related layer are incremented for higher estimations of *k*6. The rotation parameter Ω cannot generate an extra heating to the system as shown in Figure 16. Temperature *θ*(*ζ*) is decreased on increasing the parameter Ω. The physical reason is that enhancement in Ω causes to improve the internal source of energy, that is why the fluid temperature is reduced. The system gets the parameter *Pr* for the designated values 1.00, 3.50, and 6.00 during the process and increases the temperature shown through Figure 17. The direct relation of *Pr* and thermal conductivity increases the thickness of thermal boundary layer. Larger values of *Pr* generate the high diffusion of heat transfer. The temperature *θ*(*ζ*) is changed to lowest level after the exchange of high values of magnetic field parameter *M* as shown in Figure 18. The reason is that strong Lorentz forces resist the flow of nanoparticles, so causing no high collision among the nanoparticles, consequently, the temperature is decreased. Figure 19 depicts that with the increasing values of thermal radiation parameter *Rd*, the temperature *θ*(*ζ*) of ZnO-C2H6O<sup>2</sup> increases while the temperature of hybrid nanofluid Au-ZnO-C2H6O<sup>2</sup> decreases. The reason is that radiation enhances more heat in the working fluids.
