A pulse detonation engine (PDE) is one of candidates of aerospace engines for supersonic cruse. In the paper, a supersonic nozzle ejector is designed to increase thrust of single pulse detonation for methane-oxygen an...A pulse detonation engine (PDE) is one of candidates of aerospace engines for supersonic cruse. In the paper, a supersonic nozzle ejector is designed to increase thrust of single pulse detonation for methane-oxygen and hydrogen-oxygen mixtures. The design method is based on the conventional characteristic method and inlet condition is averaged value of detonations of methane-oxygen and hydrogen-oxygen mixtures. Comparison of thrusts with a design nozzle and no nozzle (straight- type) is conducted to ensure the designed nozzle performance. Furthermore, the flow velocity, temperature and velocity of the designed nozzle are calculated to ensure its appropriateness with the commercial software ANSYS CFX. Consequently, we succeed in increasing the thrusts of the single pulse detonation with the nozzle, which are 1.4 and 2.0 times as large as ones of straight- type for methane-oxygen and hydrogen-oxygen mixtures respectively.展开更多
The breakthrough developments in geospatial technologies and the increasing availability of spatial data make geoinformation a business and a decisional element to the management.Hence,it is important to have a manage...The breakthrough developments in geospatial technologies and the increasing availability of spatial data make geoinformation a business and a decisional element to the management.Hence,it is important to have a management plan to factor in practical and feasible data sources,in building geo applications.The authors of this paper are motivated by the fact that right data sources could outclass in-house resources in various application scenarios.This paper outlines pragmatic cases for the tangible benefits of the existing potential data and expeditious patterns for digital earth.This work also proposes‘good-enough’solutions based on the pragmatic cases,available literature,and the 3D city model developed that could be sufficient in contriving the objectives of the common public usage and open business models.To demonstrate this approach,the paper encapsulated the low-cost development of virtual 3D city model using publicly available cadastral data and web services.展开更多
文摘A pulse detonation engine (PDE) is one of candidates of aerospace engines for supersonic cruse. In the paper, a supersonic nozzle ejector is designed to increase thrust of single pulse detonation for methane-oxygen and hydrogen-oxygen mixtures. The design method is based on the conventional characteristic method and inlet condition is averaged value of detonations of methane-oxygen and hydrogen-oxygen mixtures. Comparison of thrusts with a design nozzle and no nozzle (straight- type) is conducted to ensure the designed nozzle performance. Furthermore, the flow velocity, temperature and velocity of the designed nozzle are calculated to ensure its appropriateness with the commercial software ANSYS CFX. Consequently, we succeed in increasing the thrusts of the single pulse detonation with the nozzle, which are 1.4 and 2.0 times as large as ones of straight- type for methane-oxygen and hydrogen-oxygen mixtures respectively.
文摘The breakthrough developments in geospatial technologies and the increasing availability of spatial data make geoinformation a business and a decisional element to the management.Hence,it is important to have a management plan to factor in practical and feasible data sources,in building geo applications.The authors of this paper are motivated by the fact that right data sources could outclass in-house resources in various application scenarios.This paper outlines pragmatic cases for the tangible benefits of the existing potential data and expeditious patterns for digital earth.This work also proposes‘good-enough’solutions based on the pragmatic cases,available literature,and the 3D city model developed that could be sufficient in contriving the objectives of the common public usage and open business models.To demonstrate this approach,the paper encapsulated the low-cost development of virtual 3D city model using publicly available cadastral data and web services.
