The flow through a rotating U bend duct is investigated by means of visualization. The U bend duct has a cross section of 50 mm×50 mm and a ratio of bend mean radius R c to hydraulic diameter of the duct D of ...The flow through a rotating U bend duct is investigated by means of visualization. The U bend duct has a cross section of 50 mm×50 mm and a ratio of bend mean radius R c to hydraulic diameter of the duct D of 0.65. The rotation axis is parallel with the bend axis. Three cases with rotation number of Ro=-0.2, 0 and 0.2, respectively, are studied at a Reynolds number of 100 000. The results show that the combined effect of rotation and bend curvature strongly influences the flow field, especially in the downstream region of the bend. The evident difference among the flow patterns with different rotation number shows that the secondary flow induced by Coriolis force takes an important role in determining the flow structure.展开更多
Solid particle erosion is a micromechanical process that is influenced by flow geometry, material of the impacting surface, impact angle, particle size and shape, particle velocity, flow condition and fluid properties...Solid particle erosion is a micromechanical process that is influenced by flow geometry, material of the impacting surface, impact angle, particle size and shape, particle velocity, flow condition and fluid properties. Among the various factors, particle size and velocity have been considered to be the most important parameters that cause erosion. Particle size and velocity are influenced by surrounding flow velocities and carrying fluid properties. Higher erosion rates have been observed in gas-solid flow in geometries where the flow direction changes rapidly, such as elbows, tees, valves, etc, due to local turbulence and unsteady flow behaviors. This paper presents the results of a Computational fluid dynamic (CFD) simulation of dilute gas-solid flow through a U-Bend and the dynamics behavior of entrained solid particles in the flow. The effect of liquid and gas velocities on location of erosion were investigated for 50, 100, 150, 200, 250 and 300 microns sand particles. Three different fluid velocities of 15, 30.48 and 45 m/s were used in the CFD analysis. The magnitude and location of erosion presented in the paper can be used to determine the areas susceptible to maximum erosive wear in elbows and U-bends, along with corresponding rate of metal loss in these areas.展开更多
文摘The flow through a rotating U bend duct is investigated by means of visualization. The U bend duct has a cross section of 50 mm×50 mm and a ratio of bend mean radius R c to hydraulic diameter of the duct D of 0.65. The rotation axis is parallel with the bend axis. Three cases with rotation number of Ro=-0.2, 0 and 0.2, respectively, are studied at a Reynolds number of 100 000. The results show that the combined effect of rotation and bend curvature strongly influences the flow field, especially in the downstream region of the bend. The evident difference among the flow patterns with different rotation number shows that the secondary flow induced by Coriolis force takes an important role in determining the flow structure.
文摘Solid particle erosion is a micromechanical process that is influenced by flow geometry, material of the impacting surface, impact angle, particle size and shape, particle velocity, flow condition and fluid properties. Among the various factors, particle size and velocity have been considered to be the most important parameters that cause erosion. Particle size and velocity are influenced by surrounding flow velocities and carrying fluid properties. Higher erosion rates have been observed in gas-solid flow in geometries where the flow direction changes rapidly, such as elbows, tees, valves, etc, due to local turbulence and unsteady flow behaviors. This paper presents the results of a Computational fluid dynamic (CFD) simulation of dilute gas-solid flow through a U-Bend and the dynamics behavior of entrained solid particles in the flow. The effect of liquid and gas velocities on location of erosion were investigated for 50, 100, 150, 200, 250 and 300 microns sand particles. Three different fluid velocities of 15, 30.48 and 45 m/s were used in the CFD analysis. The magnitude and location of erosion presented in the paper can be used to determine the areas susceptible to maximum erosive wear in elbows and U-bends, along with corresponding rate of metal loss in these areas.
基金support of the Science and Technology Research project of Hebei University(Grant No.ZD2018088)sponsored by the Natural Science Foundation of Hebei Province(E2020402052)the Key R&D Projects in Hebei Province(20374503D).
