CFD based design gas rotameters: Dynamic mesh transient simulation

Rotameters are variable-area flowmeters widely used in various industries. In this paper, a comprehensive discussion has been presented on simulation of transient behavior of a rotameter using Computational Fluid Dynamics (CFD) technique. Various methods of dynamic meshing and the reasons behind choosing the diffusion-based model have been discussed. 2D and 3D simulations were compared, and in the 2D simulation, triangular and quadratic meshes were compared, and their orthogonal quality changes due to dynamic mesh methods are shown. It was illustrated that triangular mesh cells preserve their orthogonal quality far more effectively. Moreover, the CFD simulation results were validated by comparing them with experimental data obtained from a real rotameter and it was found that the 3D simulation results are more consistent with experimental data than the 2D simulation results. A difference of less than 4% has been observed between the simulation and experimental results, indicating a reasonable agreement. The CFD solver configuration and simulation steps presented in this paper can be used to optimize rotameter designs and improve their performance. Additionally, the simulation results can provide valuable insights into the behavior of the rotameter, allowing designers to identify the potential areas for improvement and optimization of the design, accordingly.