The operating conditions of vent system for underground gas storage was introduced. The numerical simulation of the diffusion process of natural gas was conducted using process hazard analysis software tool （PHAST） ...The operating conditions of vent system for underground gas storage was introduced. The numerical simulation of the diffusion process of natural gas was conducted using process hazard analysis software tool （PHAST） with gas release velocity greater than 40 000 m^3/h. The effects of release velocity, atmospheric stability and wind speed on the diffusion area, flash fire, explosion and spray fire of natural gas were analyzed. The results show that the higher release velocity is, the bigger explosive area is; the stabler atmosphere is, the less natural gas diffuses; the lower wind speed is, the less natural gas diffuses, and the lower diffusion speed is, the bigger dangerous area is. Moreover, wind speed also has an effect on flash fire and heat radiation. In order to ensure safety of vent process of natural gas storage, the release velocity should be controlled and atmospheric conditions should be considered at the same time.展开更多
The numerical solution of large scale multi-dimensional convection diffusion equations often requires efficient parallel algorithms.In this work,we consider the extension of a recently proposed non-overlapping domain ...The numerical solution of large scale multi-dimensional convection diffusion equations often requires efficient parallel algorithms.In this work,we consider the extension of a recently proposed non-overlapping domain decomposition method for two dimensional time dependent convection diffusion equations with variable coefficients. By combining predictor-corrector technique,modified upwind differences with explicitimplicit coupling,the method under consideration provides intrinsic parallelism while maintaining good stability and accuracy.Moreover,for multi-dimensional problems, the method can be readily implemented on a multi-processor system and does not have the limitation on the choice of subdomains required by some other similar predictor-corrector or stabilized schemes.These properties of the method are demonstrated in this work through both rigorous mathematical analysis and numerical experiments.展开更多
文摘The operating conditions of vent system for underground gas storage was introduced. The numerical simulation of the diffusion process of natural gas was conducted using process hazard analysis software tool （PHAST） with gas release velocity greater than 40 000 m^3/h. The effects of release velocity, atmospheric stability and wind speed on the diffusion area, flash fire, explosion and spray fire of natural gas were analyzed. The results show that the higher release velocity is, the bigger explosive area is; the stabler atmosphere is, the less natural gas diffuses; the lower wind speed is, the less natural gas diffuses, and the lower diffusion speed is, the bigger dangerous area is. Moreover, wind speed also has an effect on flash fire and heat radiation. In order to ensure safety of vent process of natural gas storage, the release velocity should be controlled and atmospheric conditions should be considered at the same time.
基金the National Natural Science Foundation of China(No.10571017)supported in part by the National Natural Science Foundation of China(No.60533020)supported in part by NSF DMS 0712744
文摘The numerical solution of large scale multi-dimensional convection diffusion equations often requires efficient parallel algorithms.In this work,we consider the extension of a recently proposed non-overlapping domain decomposition method for two dimensional time dependent convection diffusion equations with variable coefficients. By combining predictor-corrector technique,modified upwind differences with explicitimplicit coupling,the method under consideration provides intrinsic parallelism while maintaining good stability and accuracy.Moreover,for multi-dimensional problems, the method can be readily implemented on a multi-processor system and does not have the limitation on the choice of subdomains required by some other similar predictor-corrector or stabilized schemes.These properties of the method are demonstrated in this work through both rigorous mathematical analysis and numerical experiments.
