Plasma-assisted combustion technology has been a hot spot in aero-engines andscramjet-engines.The electron density is a key discharge parameter related to the active-particledensity.The latter has been considered play...Plasma-assisted combustion technology has been a hot spot in aero-engines andscramjet-engines.The electron density is a key discharge parameter related to the active-particledensity.The latter has been considered playing an important role in the above applications bythe kinetic effect.In this work,an atmospheric pressure air plasma collisional-radiative model con-sidering the excited states of atomic nitrogen and oxygen is built based on previous widely kineticinvestigations of molecules and radicals,as well as their excited states.The excited states,especiallythe atomic nitrogen and oxygen states were less investigated in previous works.The emission inten-sity distributions from the model have a good agreement with those measured in the glide arcplasma with two discharge modes,as well as the microwave plasma.Based on the kinetics of molec-ular and atomic emitting states,the line-ratio method is presented to determine the electron density.The N_(2)(337 nm)/O(844 nm)and N_(2)(337 nm)/NO(γ)line ratios are used for the glide arc plasma andmicrowave plasma torch,respectively.Besides,the kinetics of the excited states involved with twoline-ratios are also investigated in the two types of discharges.Combined with the atmospheric pres-sure actinometry method,the kinetic effect of the plasma-assisted combustion can be revealed quan-titatively in the future.展开更多
In this paper, we reveal a direct relation between the generalized one-dimensional Carinena-Ranada- Santander （ORS） model and the radial part of two-dimensional generalized Higgs model. By this relation, we construc...In this paper, we reveal a direct relation between the generalized one-dimensional Carinena-Ranada- Santander （ORS） model and the radial part of two-dimensional generalized Higgs model. By this relation, we construct a series of quasi-exactly solutions for the two-dimensional Higgs model from a solved generalized CRS model.展开更多
The isothermal compression tests were carried out on Gleeble-3500 thermal-mechanical simulation machine in a temperature range of 298-473 K and strain rate range of 0.001-10 s^-1. The experimental results show that th...The isothermal compression tests were carried out on Gleeble-3500 thermal-mechanical simulation machine in a temperature range of 298-473 K and strain rate range of 0.001-10 s^-1. The experimental results show that the flow stress data are negatively correlated with temperature for temperature softening, and the strain rates sensitivity of this composite increases with elevating temperature. Based on the experimental data, Johnson-Cook, modified Johnson-Cook and Arrhenius constitutive models were established. The accuracy of these three constitutive models was analyzed and compared. The results show that the values predicted by Johnson-Cook model could not agree well with the experimental values. The prediction accuracy of Arrhenius model is higher than that of Johnson-Cook model but lower than that of the Modified Johnson-Cook model.展开更多
基金supported by the National Key Lab of Aerospace Power System and Plasma Technology Foundation,China(No.6142202210101)the National Science and Technology Major Project,China(No.J2019-Ⅲ-0013-0056)+2 种基金the National Natural Science Foundation of China(No.52025064)supported by the National Natural Science Foundation of China(Nos.52350072 and 52277167)the Beijing Natural Science Foundation,China(No.1242030)。
文摘Plasma-assisted combustion technology has been a hot spot in aero-engines andscramjet-engines.The electron density is a key discharge parameter related to the active-particledensity.The latter has been considered playing an important role in the above applications bythe kinetic effect.In this work,an atmospheric pressure air plasma collisional-radiative model con-sidering the excited states of atomic nitrogen and oxygen is built based on previous widely kineticinvestigations of molecules and radicals,as well as their excited states.The excited states,especiallythe atomic nitrogen and oxygen states were less investigated in previous works.The emission inten-sity distributions from the model have a good agreement with those measured in the glide arcplasma with two discharge modes,as well as the microwave plasma.Based on the kinetics of molec-ular and atomic emitting states,the line-ratio method is presented to determine the electron density.The N_(2)(337 nm)/O(844 nm)and N_(2)(337 nm)/NO(γ)line ratios are used for the glide arc plasma andmicrowave plasma torch,respectively.Besides,the kinetics of the excited states involved with twoline-ratios are also investigated in the two types of discharges.Combined with the atmospheric pres-sure actinometry method,the kinetic effect of the plasma-assisted combustion can be revealed quan-titatively in the future.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11175089 and 11075077the National Basic Research Program of China under Grant No.2012CB921900
文摘In this paper, we reveal a direct relation between the generalized one-dimensional Carinena-Ranada- Santander （ORS） model and the radial part of two-dimensional generalized Higgs model. By this relation, we construct a series of quasi-exactly solutions for the two-dimensional Higgs model from a solved generalized CRS model.
基金Funded by the Program of International S&T Cooperation(No.2013DFA51230)the Opening Subject Fund of Ningbo University(No.zj1226)
文摘The isothermal compression tests were carried out on Gleeble-3500 thermal-mechanical simulation machine in a temperature range of 298-473 K and strain rate range of 0.001-10 s^-1. The experimental results show that the flow stress data are negatively correlated with temperature for temperature softening, and the strain rates sensitivity of this composite increases with elevating temperature. Based on the experimental data, Johnson-Cook, modified Johnson-Cook and Arrhenius constitutive models were established. The accuracy of these three constitutive models was analyzed and compared. The results show that the values predicted by Johnson-Cook model could not agree well with the experimental values. The prediction accuracy of Arrhenius model is higher than that of Johnson-Cook model but lower than that of the Modified Johnson-Cook model.
