As the thermal radiation is one of the fundamental modes of heat transfer, therefore, this study looks at the influences of thermal radiation and magnetic field on the peristaltic flow of Jeffrey nanofluid in a tapered asymmetric channel. Two models of viscosity are debated in the present study, Model-(I), all parameters that are depended on viscosity in their definitions, behaves as a constant (as treated before in nanofluid researches). Model-(II), these known parameters are considered vary with the temperature of flow. Under the assumption of long wavelength and low Reynolds number, the problem rearranged. The resulting system of partial differential equations (PDEs) is accounted semi-analytically by means of multi-step differential transform method (Ms-DTM) technique, with aid of Mathematica 11. The streamlines graphs are offered in the terminus, which elucidate the trapping bolus phenomenon. As a special case, a comparison between the prior results and recent published results by Gnaneswara Reddy and Makinde [10] has been made and signified to prove the validity of the present results. The comparisons are shown in Table 1 and found to be widely agreed. The semi-analytical results had shown that, as the thermal radiation increases, the nanoparticles diameter and concentration of fluid increase (thermal radiation is a decreasing function in temperature when the temperature decreases, the diameter of the nanoparticles increases, i.e., the volume of nanoparticle and its concentration increase and become more effective near to tumor tissues). Consequently, it can be used as an agent for radiation therapy which generates rise in localized radiation doses and selectively target tumor cells for localized damages (radiotherapy of oncology).

peristalsis, Jeffrey Nanofluid, thermal radiation, temperature-dependent viscosity, magnetic field, tapered asymmetric channel, Ms-DTM.