*5.5. Drag Force Coe*ffi*cient and Heat Transfer Rate*

Influence of Hartmann number *M*, Hall current parameter m, stretching parameter γ<sup>1</sup> and γ2, and Reynolds number on Skin friction coefficients for MWCNTs and SWCNTs at both disks is portrayed in Table 4. Skin coefficient friction decrease by increasing the value of Hall current parameter m and Hartmann number *M* at lower and upper disk for both MWCNTs and SWCNTs, while increasing behavior for *Re* and scaled stretching parameter γ<sup>1</sup> for disk at *z* = 0 and stretching parameter γ<sup>2</sup> for the disk at *z* = *h*(*t*) for both MWCNTs and SWCNTs.

**Table 4.** Numerical values of drag force coefficient at lower and upper disk for SWCNTs and MWCNTs when *A*<sup>1</sup> = 0.5, Pr = 6.7, Ω = 0.5, *S* = 0.4, *k*1 = 0.1, *k*2 = 0.1, *m* = 0.5, *Sc* = 1.


Table 5 is erected to depict the impact of numerous parameters on heat transfer rate. It is gathered that rate of heat transfer is a decreasing function of unsteadiness parameter and Prandtl number at lower disk for both MWCNTS and SWCNTs, while it is a decreasing function of Reynolds number at lower disk and increasing function of Reynolds number at upper disk for both MWCNTs and SWCNTs.


**Table 5.** Numerical values of heat transfer rate at lower and upper disk for SWCNTs and MWCNTs when Ω = 0.5, γ<sup>1</sup> = 0.1, γ<sup>2</sup> = 0.4, *k*1 = 0.1, *k*2 = 0.1, *m* = 0.5, *Sc* = 1.
