Insight into Significance of Nanoparticle Aggregation, Dust Particles, and Pollutant Sources on the Dynamics of EMHD Nanofluids

The study of heat and mass transport mechanisms in nanofluids is increasingly important due to issues related to contamination, such as dust particles, nanoparticle clusters, and other contaminants affecting the fundamental physics of flow. This study investigates a two-dimensional, steady, incompressible. Electromagnetic hydrodynamic (EMHD) nanofluid flow with nanoparticles under the influence of mass diffusion, nanoparticle aggregation, viscous dissipation, and pollutant generation. A system of nonlinear ordinary differential equations (ODEs) is developed from the governing coupled partial differential equations (PDEs) by applying appropriate similarity transformations and is then solved numerically using the bvp4c solver in MATLAB. Validation of this model is performed against prior studies of limiting cases, confirming its correctness. The effects of both homogeneous and aggregated nanoparticles on the velocity, temperature, and concentration distributions are analyzed. Results indicate that higher magnetic parameter results in lower velocities and larger thermal and mass diffusive boundary layers; whereas an increase in the electric field strength leads to increased flow velocities. Additionally, nanoparticle aggregation increases energy and mass storage within the fluid; however, it decreases heat and mass transfer rates at the wall. Furthermore, an increase in the source of pollutants to the fluid causes contaminants to accumulate in both the fluid phase and dust phase, indicating potential environmental impacts. Overall, these findings can be used to help optimize the design of cooling systems, electromagnetic flow systems, and pollution control processes.