We proposed a novel impact pneumatic cylinder with a reservoir connected to the inlet chamber so that the pneumatic cylinder can achieve a high speed. A reservoir with high-pressure air enabled the cylirider to achiev...We proposed a novel impact pneumatic cylinder with a reservoir connected to the inlet chamber so that the pneumatic cylinder can achieve a high speed. A reservoir with high-pressure air enabled the cylirider to achieve considerable＇acceleration when it began to Work. We established a mathematical model to simulate the behaviors of an impact pneumatic cylinder, focusing on the relationships of the maximum piston speed with the air supply pressure and the reservoir volume. The results show that the reservoir .can help significantly enhance the pneumatic system velocity. When the reservoir volume is less than double the cylinder volume, an increase in the reservoir volume is more effective in increasing the maximum piston velocity.展开更多
To investigate the influence of coherent structures in the gas-particle wake flow, direct numerical simulation (DNS) method was adopted to compute a two-dimensional particle laden wake flow. A high accuracy spectral e...To investigate the influence of coherent structures in the gas-particle wake flow, direct numerical simulation (DNS) method was adopted to compute a two-dimensional particle laden wake flow. A high accuracy spectral element method (SEM) was employed to simulate the gas flow field and a Lagrangian approach was used to compute the particles movement. Numerical results showed that at the same Stokes numbers, particles would be greatly impacted by the development of the coherent structure. But with different Stokes numbers, it can be seen that the large-scale vortex structures would influence the particle flow differently. While under different Reynolds numbers (150 and 200), there are no great changes in the particle laden flow.展开更多
文摘We proposed a novel impact pneumatic cylinder with a reservoir connected to the inlet chamber so that the pneumatic cylinder can achieve a high speed. A reservoir with high-pressure air enabled the cylirider to achieve considerable＇acceleration when it began to Work. We established a mathematical model to simulate the behaviors of an impact pneumatic cylinder, focusing on the relationships of the maximum piston speed with the air supply pressure and the reservoir volume. The results show that the reservoir .can help significantly enhance the pneumatic system velocity. When the reservoir volume is less than double the cylinder volume, an increase in the reservoir volume is more effective in increasing the maximum piston velocity.
文摘To investigate the influence of coherent structures in the gas-particle wake flow, direct numerical simulation (DNS) method was adopted to compute a two-dimensional particle laden wake flow. A high accuracy spectral element method (SEM) was employed to simulate the gas flow field and a Lagrangian approach was used to compute the particles movement. Numerical results showed that at the same Stokes numbers, particles would be greatly impacted by the development of the coherent structure. But with different Stokes numbers, it can be seen that the large-scale vortex structures would influence the particle flow differently. While under different Reynolds numbers (150 and 200), there are no great changes in the particle laden flow.
