The effects of three factors （i.e., drop height h, hopper outlet diameter do, and material temperature T] on the dust generation rate derived from a free falling particle stream were investigated via filll factorial ...The effects of three factors （i.e., drop height h, hopper outlet diameter do, and material temperature T] on the dust generation rate derived from a free falling particle stream were investigated via filll factorial experiments. The correlation between the three factors and dust generation rate was also analysed. Results show that Tand h affect the first fugitive dust rate largely, whereas the second fugitive dust rate is mainly dominated by h and do. Through analysing the first fugitive dust percentage data, it is found that h and T should be considered first for higher temperatures and lower flow rates, whereas h and do can be considered under contrasting conditions, and h should be controlled in the remaining two sets of conditions. Relationships between the influencing factors and total and first fugitive dust rates were developed via multiple regression to quantify the dust emission rates for different contact surfaces （rigid or water）.展开更多
Jupiter is one of the major targets for planetary exploration,and dust in the Jovian system is of great interest to researchers in the field of planetary science.In this paper,we review the five dust populations outsi...Jupiter is one of the major targets for planetary exploration,and dust in the Jovian system is of great interest to researchers in the field of planetary science.In this paper,we review the five dust populations outside the ring system:grains in the region of the Galilean moons,potential dust from plumes on Europa,Jovian stream particles,particles in the outer region of the Jovian system ejected from the irregular satellites,and dust in the region of the Trojan asteroids.The physical environment for the dust dynamics is described,including the gravity,the magnetic field and the plasma environment.For each population,the dust sources are described,and the relevant perturbation forces are discussed.Observations and results from modeling are reviewed,and the distributions of the individual dust populations are shown.The understanding of the Jovian dust environment allows to assess the dust hazard to spacecraft,and to characterize the material exchange between the Jovian moons,their surface properties and distribution of non-icy constituents.展开更多
文摘The effects of three factors （i.e., drop height h, hopper outlet diameter do, and material temperature T] on the dust generation rate derived from a free falling particle stream were investigated via filll factorial experiments. The correlation between the three factors and dust generation rate was also analysed. Results show that Tand h affect the first fugitive dust rate largely, whereas the second fugitive dust rate is mainly dominated by h and do. Through analysing the first fugitive dust percentage data, it is found that h and T should be considered first for higher temperatures and lower flow rates, whereas h and do can be considered under contrasting conditions, and h should be controlled in the remaining two sets of conditions. Relationships between the influencing factors and total and first fugitive dust rates were developed via multiple regression to quantify the dust emission rates for different contact surfaces （rigid or water）.
基金the European Space Agency under the project“Jovian Micrometeoroid Environment Model”(JMEM)(Contract No.4000107249/12/NL/AF)at the University of Oulu,and by the Academy of Finland under the project“Earth and Near-Space System and Environmental Change”.
文摘Jupiter is one of the major targets for planetary exploration,and dust in the Jovian system is of great interest to researchers in the field of planetary science.In this paper,we review the five dust populations outside the ring system:grains in the region of the Galilean moons,potential dust from plumes on Europa,Jovian stream particles,particles in the outer region of the Jovian system ejected from the irregular satellites,and dust in the region of the Trojan asteroids.The physical environment for the dust dynamics is described,including the gravity,the magnetic field and the plasma environment.For each population,the dust sources are described,and the relevant perturbation forces are discussed.Observations and results from modeling are reviewed,and the distributions of the individual dust populations are shown.The understanding of the Jovian dust environment allows to assess the dust hazard to spacecraft,and to characterize the material exchange between the Jovian moons,their surface properties and distribution of non-icy constituents.
