Mechanical Engineering
Seyed Masoud Vahedi; Farzad Parvaz; Mohsen Khandan Bakavoli; Mohammad Kamali
Abstract
Separation of suspended droplets in a fluid flow has been a great concern for scientists and technologists. In the current study, the effect of the surface roughness on flow field and the performance of a gas-oil cyclone is studied numerically. The droplets and the turbulent airflow inside the cyclone ...
Read More
Separation of suspended droplets in a fluid flow has been a great concern for scientists and technologists. In the current study, the effect of the surface roughness on flow field and the performance of a gas-oil cyclone is studied numerically. The droplets and the turbulent airflow inside the cyclone are considered to be the discrete and continuous phases respectively. The Reynolds stress model (RSM) is employed to simulate the complex, yet strongly anisotropic, flow inside the cyclone while the Eulerian-Lagrangian approach is selected to track droplet motion. The results are compared to experimental studies; according to the results, the tangential and axial velocities, pressure drop, and Euler number decrease when the surface roughness increases. Moreover, the cyclone efficiency drops when the vortex length decreases as a result of a rise in surface roughness. The differences between the numerical and experimental results become significant at higher flow rates. By calculating the impact energy of droplets and imposing the film-wall condition on the walls, splash does not occur.
Mechanical Engineering – Applied Design
Seyed Masoud Vahedi; Farzad Parvaz; Mohammad Kamali; Hasti Jafari Jebeli
Abstract
The effect of adding extra inlet channels on the operation of the Stairmand Cyclone has been investigated numerically. The Reynolds stress model (RSM) and Eulerian-Lagrangian method were used to investigate the complex turbulent flow and cyclone performance. The impacts of one-way coupling and two-way ...
Read More
The effect of adding extra inlet channels on the operation of the Stairmand Cyclone has been investigated numerically. The Reynolds stress model (RSM) and Eulerian-Lagrangian method were used to investigate the complex turbulent flow and cyclone performance. The impacts of one-way coupling and two-way coupling models on the cyclone efficiency and the calculation of cut-off size diameter were examined. The results showed that a rise in channel number increases the tangential velocity and extends the Rankine vortex region. Moreover, in the four-inlet cyclone, the direction of flow changes unlike the one-inlet and two-inlet cyclones, and it behaves like a jet flow. According to the results, the collection efficiency and cut-off size diameter of the four-inlet cyclone are respectively about 10.78% higher and 35% lower than those of one-inlet configuration. Therefore, the performance of four-inlet cyclone is the highest among the three investigated configurations due to high tangential and axial velocities. A cyclone with more inlets has a more symmetrical flow pattern. Consequently, the four-inlet cyclone has the lowest flux of erosion among the others. The results of cyclone performance reveal a slight difference between one-way coupling and two-way coupling models.
