Effect of a Uniform Magnetic Field on the Growth of a Gas Bubble in a Viscous, Supersaturated Nanofluid: Implemented to Fe ₃ O ₄ /Water Magnetic Nanofluid

ABSTRACT Several experimental studies revealed that magnetic fields have significant effects on nanofluids characteristics, which in turn should affect bubble dynamics in gas–nanofluids systems that may arise in applications of nanotechnology. We devote our effort to investigate the effect of magnetic field on the growth of gas bubbles by mass diffusion of supersaturated, dissolved gas in gas–nanofluid bubbly flow. The problem is solved analytically for a general nanofluid, then the results are implemented for magnetic nanofluids since they can be magnetically controllable; consequently, magnetic nanofluids have a wide range of applications, particularly in health care and agriculture. The results were validated by comparing them with the validated experimental studies for the case of magnetized water solution, where the results are in good agreement with the experimental results. The sensitivity analysis is investigated for the affecting parameters and its influence on the bubble growth cost. The findings reveal that the positively affected parameters on the bubble growth include the diffusivity coefficient, initial pressure difference and its coefficient, and the Jakob number which depends on initial supersaturation, on the contrary, the negatively affected parameters include magnetic nanofluid viscosity, initial void fraction, magnetic field intensity, electrical conductivity, and nanoparticles' volume fraction. Moreover, the evolution of the dynamic pressure balance at the bubble surface and the concentration distribution around the growing carbon dioxide bubble are investigated.