Magneto-Hydrodynamic effects on Diesel/CNG bubbly flow enhanced by Fe₃O₄ Nanoparticles: Experimental and mathematical assessments

In the present study, the magneto hydrodynamic (MHD) was applied to the motion analysis of compressed natural gas (CNG) bubbles in laminar diesel flow after enhancing the liquid fuel with iron oxide nanoparticles (Fe₃O₄) in a horizontal pipe using experimental and mathematical approaches. Two distinct techniques were adopted for the experimental measurements: High speed video camera system (HSVC) and particle image velocimetry (PIV). The result of the PIV investigation indicates that increasing the intensity of the magnetic field changed the axial velocity profile of the diesel/nanoparticle mixture from the parabolic to a relatively flat shape. Whilst to illustrate the effect of magnetic field on bubble velocity, the axial and vertical components of the bubble velocity were computed by keeping track of the geometric center of the bubble from frame to frame recorded by HSVC. Moreover, the fundamental equation of motion of a single CNG bubble based upon Newton's law under a forced magnetic field were derived and presented. The origination processes of the velocity dispersion of the liquid and gas stages of the bubbly flow were equally discussed. The governing partial-differential equations were numerically determined by means of a 4th order Runge-Kutta method. The outcomes from the model solution indicate that at magnetic field intensity (B = 0), the comparison between mathematical and experimental results in literature for the average axial and perpendicular components of bubble velocity resulted in mean percentage differences of 10.4 % and 15.6 % respectively.