Gate valve has various placements in the practical usages.Due to the effect of gravity,particle trajectories and erosions are distinct between placements.Thus in this study,gas-solid flow properties and erosion in gat...Gate valve has various placements in the practical usages.Due to the effect of gravity,particle trajectories and erosions are distinct between placements.Thus in this study,gas-solid flow properties and erosion in gate valve for horizontal placement and vertical placement are discussed and compared by using Euler-Lagrange simulation method.The structure of a gate valve and a simplified structure are investigated.The simulation procedure is validated in our published paper by comparing with the experiment data of a pipe and an elbow.The results show that for all investigated open degrees and Stokes numbers(St),there are little difference of gas flow properties and flow coefficients between two placements.It is also found that the trajectories of particles for two placements are mostly identical when St << 1,making the erosion independent of placement.With the increase of St,the distinction of trajectories between placements becomes more obvious,leading to an increasing difference of the erosion distributions.Besides,the total erosion ratio of surface T for horizontal placement is two orders of magnitudes larger than that for vertical placement when the particle diameter is 250 μm.展开更多
The dashboard is the most important part of the large inner decoration of cars;it should not only have enough strength and rigidity,but also have a harmonious body model which can unify the theme.Besides,it needs to r...The dashboard is the most important part of the large inner decoration of cars;it should not only have enough strength and rigidity,but also have a harmonious body model which can unify the theme.Besides,it needs to reach the goal of lightweight.In order to achieve these three goals,the car dashboard is made by engineering-plastics and adopts the technology of injection moulding.This paper introduces the keys of design and the advanced technology of large injection moulding for car dashboard.展开更多
基金supported by National Natural Science Foundation of China(Grant No.21276241)etc
文摘Gate valve has various placements in the practical usages.Due to the effect of gravity,particle trajectories and erosions are distinct between placements.Thus in this study,gas-solid flow properties and erosion in gate valve for horizontal placement and vertical placement are discussed and compared by using Euler-Lagrange simulation method.The structure of a gate valve and a simplified structure are investigated.The simulation procedure is validated in our published paper by comparing with the experiment data of a pipe and an elbow.The results show that for all investigated open degrees and Stokes numbers(St),there are little difference of gas flow properties and flow coefficients between two placements.It is also found that the trajectories of particles for two placements are mostly identical when St << 1,making the erosion independent of placement.With the increase of St,the distinction of trajectories between placements becomes more obvious,leading to an increasing difference of the erosion distributions.Besides,the total erosion ratio of surface T for horizontal placement is two orders of magnitudes larger than that for vertical placement when the particle diameter is 250 μm.
文摘The dashboard is the most important part of the large inner decoration of cars;it should not only have enough strength and rigidity,but also have a harmonious body model which can unify the theme.Besides,it needs to reach the goal of lightweight.In order to achieve these three goals,the car dashboard is made by engineering-plastics and adopts the technology of injection moulding.This paper introduces the keys of design and the advanced technology of large injection moulding for car dashboard.
