CFD Simulation of Concentration Sensor

Abstract

This thesis deals with the CFD modelling of a NaCl concentration sensor, specifically its pressure drop, but also velocity and pressure profile. The main goal of the work is twofold: firstly, to confirm whether the simulations are suitable to describe the fluid behaviour in the sensor, secondly, to improve sensor design. Firstly, the original sensor was simulated and the simulation results were compared with the experimental ones. After the first simulation, the match was not satisfactory, due to the inappropriate mesh, therefore the new type of mesh was used. After that, the sensitivity analysis was done to find out, how the simulation is influenced by the geometry changes. It was found that even a very small geometry change can greatly affect the overall pressure drop in the sensor. The next aim was to design a completely new sensor, which will have lower pressure drop than the original one. Two NaCl concentration sensor designs were performed. Although the first one had a lower pressure drop, it was tricky to manufacture it and there was also a risk of fluid leakage. The second design was made and the obtained experimental results were compared with the simulation. Unfortunately, the match between results was not satisfactory. On the other hand, the aim to obtain lower pressure drop was successfully reached.