The volume of fluid model is used to simulate magneto-hydrodynamics (MHD) for CNG-Diesel bubbly flow through a horizontal pipe. The modelling is carried out in ANSYS environment and the simulation of liquid/gas bubbly flow used FLUENT MHD Module for solving and post processing the MHD bubbly flow problem. This study is divided into two models: in the first model, the dynamics of CNG bubbles formation emanating from nozzle in mixer under influencing of magnetic field is explained. While, in the second model, the dynamics of bubbly flow through horizontal pipe under influence of a magnetic field is explained. The simulation analysis was able to investigate well the MHD effects on bubble formation in liquid/gas mixers with different conditions and the two-phase MHD flow line effect. The influence of magnetic field on the axial fuel velocity, gas volume fraction along horizontal pipe was simulated. The results showed that gas bubbles move toward the upper wall under the buoyancy force effect and these bubbles expand vertically in the fuel flow, and the gas volume fraction values increased with increasing the magnetic field density. Also, the axial fuel velocity decreases and the behavior tend to flatten with increasing of the magnetic intensity. © 2018 Author(s).