Evaluation of Pressure Drop and Flow Characteristics in the Evaporator of an Exhaust System for Trucks

Sammanfattning

This thesis evaluates the key parameters affecting pressure drop and streamlines in an exhaust system for trucks. The study includes a sensitivity analysis of an evaporation unit within the exhaust system using computational fluid dynamics (CFD) simulations and the design of a rig for data collection. It aims to find any significant effects of different design parameters such as the mixer blade number and various tolerances. These parameter variations are inspected via simulations and the results are compared with each other. That being done, the effect of different configurations and setups on pressure drop and flow characteristics are obtained. It is found that the provided backpressure and the flow being seamless are trade-offs against a better mixing and hence evaporation of urea. However, within the given tolerance values, there happened to be no significant effect on flow characteristics. In contrast, actual design changes such as the mixer blade number turned out to have a big impact on how the flow behaves. As a final addition to the design evaluations, a test rig is developed to inspect the actual outcome of these changes in real world. The test rig is designed in such a way that it allows the chosen parameters to be varied on the exhaust system and provides good amount of versatility and ease of use. The findings from this study contribute to the continuous improvement of exhaust systems and design features that provide enhanced efficiency and sustainability.