CFD Analysis of Thermo-hydraulic Behaviour in the VVER-1000 Reactor Using COMSOL Multiphysics

¹ National Scientific Research institute of Renewable Energy Sources, Tashkent, Uzbekistan
² Bukhara State Medical Institute named after Abu Ali ibn Sino. Bukhara, Uzbekistan
³ Bukhara State Pedagogical Institute, Bukhara, Uzbekistan
⁴ Gulistan State University, Gulistan, Uzbekistan
⁵ Asia International University, Bukhara, Uzbekistan

^* Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.

Published online: 3 March 2026

Abstract

This article presents a two-dimensional Computational Fluid Dynamic (CFD) of the thermohydraulic behaviour of VVER -1000 reactor vessel based on COMSOL Multiphysics. The model works in a steady- state condition to examine the distribution of the flow of the coolant, along with temperature gradient and pressure differences in the reactor territory. Background conditions are specified as 515m²s/inlet flow rate and inflow temperature set at 563.15 K and natural convection imposed on the exterior of the reactor wall in order to model natural convection with the environment. The two stationary simulations provide finer results in terms of temperature, velocity and pressure contours which helps one evaluate flow uniformity and heat transfer properties. Scientific outputs are read and calculated across three sampling cut lines and found to show the effect that coolant interactions have on both local thermal conditions and pressure stability. The result of this work will help identify the VVER-1000 reactor cooling performance better and make a mathematical basis of future three- dimensional and transient analysis.