Semnan University Press Journal of Heat and Mass Transfer Research 2345-508X Articles in Press 2026 05 09 Numerical Study of the impact of peritoneal fluid and its convection on magnetic nanoparticle hyperthermia in the treatment of peritoneal metastasis مطالعه عددی تاثیر مایع صفاقی و همرفت آن بر گرمادرمانی نانوذرات مغناطیسی در درمان متاستاز صفاقی 10605 10.22075/jhmtr.2026.37513.1732 EN M.H. Tavakoli Physics Department, Bu-Ali Sina University 0000-0002-4829-8913 Mohadese Ranjbaran Department of Physics, Faculty of Science, Bu-Ali Sina University, Hamadan Zahra Keshtpour Amlashi Cancer Research Center, Hamadan University of Medical Sciences, Hamadan Safoora Nikzad Department of Medical Physics, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan Journal Article 2025 04 27 Objective: This study evaluates magnetic nanoparticle hyperthermia for treating peritoneal metastasis, focusing on the effect of ascitic fluid and convection on tumor heating and healthy tissue. <br /> Methods: Magnetic nanoparticles (MNPs) were applied to raise tumor temperature to 42–46°C under an alternating magnetic field. Finite element simulations were used to calculate magnetic field distribution (Maxwell’s equations), heat generated by MNPs (Rosensweig model), temperature in the tumor and surrounding solid tissue (Pennes bioheat equation), and fluid temperature and convection in the peritoneal cavity (Navier–Stokes equations). <br /> Results: Induction heating in the tumor was unaffected by ascitic fluid, though overall heat in the peritoneal cavity increased. Heat generated by MNPs was lowest at the tumor center and highest near the surface, with ascitic fluid enhancing heat production. Tumor temperature reached 45–46°C without ascitic fluid but decreased to 43–44°C when convection was present. Healthy tissue temperature remained below 44.2°C in both scenarios. Convective cooling in the fluid was the dominant factor influencing temperature distribution, causing non-uniform heating within the tumor. Conclusion: Magnetic nanoparticle hyperthermia effectively targets tumor tissue while protecting healthy tissue. The presence of ascitic fluid significantly alters temperature distribution through convection, highlighting the importance of considering fluid dynamics in treatment planning.