Improvement of transfer phenomena rates in open chaotic flow of nanofluid under the effect of magnetic field: Application of a combined method

•Transfer phenomena rates of nanofluid chaotic flow with the presence of magnetic field are examined.•Effects of MHD field on the fluid flow are assessed for different application modes and directions.•A combined method linking between three promoting ways of heat exchange is investigated numerically.•Amelioration of 13% in heat transfer is recorded for the optimum case compared to the standard situation. Numerical investigation is carried out in the present research in order to assess the effects of a combined technique on heat transfer and fluid motion. A linking between three promoting ways to enhance transfer phenomena presented in terms of regime flow (chaotic flow), the fluid type (nanofluid) along with a non-intrusive means (magnetic induction) is considered throughout the current study. In this project, magnetohydrodynamic MHD field is applied with two different manners; either on the full geometry or partially on selected portions of the channel. Moreover, evolutions of local and average Nusselt numbers, thermal and velocity fields, average wall shear rate in addition to the flow patterns are examined for Hartmann number, Reynolds number and different scenarios of the MHD field application and direction. Findings illustrate that Nusselt number and therefore heat transfer is an increasing function with Ha number in the case of partial mode and transversal orientation of the MHD field. While it is either a constant, decreasing or slightly augmented function with Ha in the other applications. An amelioration of about 13% in heat transfer is recorded for the optimum case compared to the standard situation (without magnetic field). Besides, it is shown that Re number grows heat exchanges with an existing critical value of Re for the transversal orientation case, where the effect of the MHD mode on the average Nu number is differently.