فهرست نشریات علمی دسترسی آزاد ایران

In this study, the effect of wall roughness on flow pattern, performance, and erosion rate in an axial gas cyclone is investigated. Gas cyclones are widely used in various industries such as food processing, dryers, and the cement industry for separating solid particles from gas flow due to their flexibility, low maintenance costs, and efficiency in air pollution control. Numerical modeling is conducted using turbulence models, surface roughness models, the discrete phase model (DPM), and the erosion model to analyze key parameters such as pressure drop, tangential velocity, axial velocity, separation efficiency, and wall erosion rate. The results indicate that increasing wall roughness reduces tangential velocity, thereby decreasing centrifugal force, which negatively affects particle separation efficiency. On the other hand, increasing wall roughness leads to a reduction in pressure drop, which is considered an advantage in cyclone design. Erosion rate analysis also shows that the highest erosion occurs in the lower conical section of the cyclone, and increasing wall roughness can reduce erosion. Overall, this study reveals that wall roughness has conflicting effects on cyclone performance—reducing pressure drop on one hand while decreasing separation efficiency on the other. Therefore, optimizing surface roughness is essential to achieve a balance between these two factors in the design of axial gas cyclones. The results showed that increasing wall roughness reduced tangential velocity by up to 18%, cyclone collection efficiency dropped by approximately 12% for particles larger than 25 μm, while pressure drop decreased by around 9%, which can be considered beneficial in energy-sensitive applications. The highest erosion rate was observed at the cone tip of the cyclone, and wall roughness helped reduce average erosion by nearly 15%.