Comparison of the Fluid Velocity of Water (H2O), Ammonia (NH3), and Mercury (Hg) in Pipes using ANSYS Simulation

Abstract

The flow behavior of fluids in piping systems is a fundamental aspect of thermal and hydraulic engineering, influencing numerous industrial processes such as cooling, heat transfer, and fluid transport. This study presents a comparative analysis of the flow velocity of three fluids—water, ammonia, and mercury —within a pipe using Computational Fluid Dynamics (CFD) simulations conducted in ANSYS Fluent. Each fluid was tested under identical geometric and boundary conditions to isolate the effects of density and viscosity on flow characteristics. The pipe model consisted of a straight section with an elbow, designed to observe changes in velocity distribution as the fluid changed direction. Simulation results revealed that all three fluids exhibited nearly identical average outlet velocities, with values of 0.520096 m/s for water, 0.520217 m/s for ammonia, and 0.520088 m/s for mercury. Despite slight variations in viscosity and density, the maximum difference between these values was only 0.0248%, indicating a negligible influence of fluid type on average flow velocity when inlet conditions are constant. Ammonia displayed the highest peak velocity due to its lower viscosity, while mercury showed the lowest as a result of its higher density. Overall, the study concludes that variations in fluid properties have minimal impact on velocity distribution under steady inlet velocity. Future research is recommended to explore the effects of temperature, pipe roughness, and turbulence to better understand fluid flow behavior in more complex industrial systems.