Gaseous detonation propagating in a toroidal chamber was numerically studied for hydrogen/oxygen/nitrogen mixtures. The numerical method used is based on the three-dimensional Euler equations with detailed finiterate ...Gaseous detonation propagating in a toroidal chamber was numerically studied for hydrogen/oxygen/nitrogen mixtures. The numerical method used is based on the three-dimensional Euler equations with detailed finiterate chemistry. The results show that the calculated streak picture is in qualitative agreement with the picture recorded by a high speed streak camera from published literature. The three-dimensional flow field induced by a continuously rotating detonation was visualized and distinctive features of the rotating detonations were clearly depicted. Owing to the unconfined character of detonation wavelet, a deficit of detonation parameters was observed. Due to the effects of wall geometries, the strength of the outside detonation front is stronger than that of the inside portion. The detonation thus propagates with a constant circular velocity. Numerical simulation also shows three-dimensional rotating detonation structures, which display specific feature of the detonation- shock combined wave. Discrete burning gas pockets are formed due to instability of the discontinuity. It is believed that the present study could give an insight into the interest- ing properties of the continuously rotating detonation, and is thus beneficial to the design of continuous detonation propulsion systems.展开更多
Electro hydrodynamic analogue (EHA) method is applied to study the flow fields in the West Lake. It gives out a satisfactory result on water velocities and discharges of the bridge openings.
The Von-Karman vortex street flow behind a circular cylinder is successfully solved at Re= 100 for incompressible N- S equations in the form of stream function and vorticity. The method adopted here involves ADI - BGE...The Von-Karman vortex street flow behind a circular cylinder is successfully solved at Re= 100 for incompressible N- S equations in the form of stream function and vorticity. The method adopted here involves ADI - BGE schemes, a recent treatment of body boundary conditions and a new acceptable perturbation model. The solutions of the flow field obtained here are better than previous numerical ones and agree with the experimental data closer. Therefore, it can be used to study sound field numerically. The Curie equation is directly and numerically solved to analyze the distribution of sound sources and the characteristics of their radiated sound field at Re= 100 and to compare with the solution from the theory of vortex sound. It is shown that this method is successful.展开更多
基金supported by the National Natural Science Foundation of China (10872096)the Open Fund of State Key Laboratory of Explosion Science and Technology, Beijing University of Science and Technology (KFJJ09-13)
文摘Gaseous detonation propagating in a toroidal chamber was numerically studied for hydrogen/oxygen/nitrogen mixtures. The numerical method used is based on the three-dimensional Euler equations with detailed finiterate chemistry. The results show that the calculated streak picture is in qualitative agreement with the picture recorded by a high speed streak camera from published literature. The three-dimensional flow field induced by a continuously rotating detonation was visualized and distinctive features of the rotating detonations were clearly depicted. Owing to the unconfined character of detonation wavelet, a deficit of detonation parameters was observed. Due to the effects of wall geometries, the strength of the outside detonation front is stronger than that of the inside portion. The detonation thus propagates with a constant circular velocity. Numerical simulation also shows three-dimensional rotating detonation structures, which display specific feature of the detonation- shock combined wave. Discrete burning gas pockets are formed due to instability of the discontinuity. It is believed that the present study could give an insight into the interest- ing properties of the continuously rotating detonation, and is thus beneficial to the design of continuous detonation propulsion systems.
文摘Electro hydrodynamic analogue (EHA) method is applied to study the flow fields in the West Lake. It gives out a satisfactory result on water velocities and discharges of the bridge openings.
基金Supported by National Natural Science Foundation of China and National Education CommissionFoundation of China
文摘The Von-Karman vortex street flow behind a circular cylinder is successfully solved at Re= 100 for incompressible N- S equations in the form of stream function and vorticity. The method adopted here involves ADI - BGE schemes, a recent treatment of body boundary conditions and a new acceptable perturbation model. The solutions of the flow field obtained here are better than previous numerical ones and agree with the experimental data closer. Therefore, it can be used to study sound field numerically. The Curie equation is directly and numerically solved to analyze the distribution of sound sources and the characteristics of their radiated sound field at Re= 100 and to compare with the solution from the theory of vortex sound. It is shown that this method is successful.
