The nanosize grain growth characteristics of spherical single-crystal titanium oxide （TiO2） during the rapid gaseous detonation reaction are discussed. Based on the experimental conditions and the Chapman-Jouguet th...The nanosize grain growth characteristics of spherical single-crystal titanium oxide （TiO2） during the rapid gaseous detonation reaction are discussed. Based on the experimental conditions and the Chapman-Jouguet theory, the Kruis model was introduced to simulate the growth characteristics of spherical TiO2 nanoparticles obtained under high pressure, high temperature and by rapid reaction. The results show that the numerical analysis can satisfactorily predict the growth characteristics of spherical TiO2 nanoparticles with diameters of 15-300 nm at different affecting factors, such as concentration of particles, reaction temperature and time, which are in agreement with the obtained experimental results. We found that the increase of the gas-phase reaction temperature, time, and particle concentration affects the growth tendency of spherical nanocrystal TiO2, which provides effective theoretical support for the controllable synthesis of multi-scale nanoparticles.展开更多
The performance of combustion driver ignited by multi-spark plugs distributed along axial direction has been analysed and tested. An improved ignition method with three circumferential equidistributed ignitors at main...The performance of combustion driver ignited by multi-spark plugs distributed along axial direction has been analysed and tested. An improved ignition method with three circumferential equidistributed ignitors at main diaphragm has been presented, by which the produced incident shock waves have higher repeatability, and better steadiness in the pressure, temperature and velocity fields of flow behind the incidence shock, and thus meets the requirements of aerodynamic experiment. The attachment of a damping section at the end of the driver can eliminate the high reflection pressure produced by detonation wave, and the backward detonation driver can be employed to generate high enthalpy and high density test flow. The incident shock wave produced by this method is well repeated and with weak attenuation. The reflection wave caused by the contracted section at the main diaphragm will weaken the unfavorable effect of rarefaction wave behind the detonation wave, which indicates that the forward detonation driver can be applied in the practice. For incident shock wave of identical strength, the initial pressure of the forward detonation driver is about 1 order of magnitude lower than that of backward detonation.展开更多
基金This research was financially supported by the Fundamental Research Funds for the Central Universities No. 2014QNA76, the Natural Science Foundation of Jiangsu Province No. BK20140178, the National Natural Science Foundation of China Nos. 11502282 and 41572263, the China Scholarship Council No.201506425040. Center of collaborative innovation in resource utilization and eco- logical restoration of the old industrial base. This is scientific research platform, temporarily with support number.
文摘The nanosize grain growth characteristics of spherical single-crystal titanium oxide （TiO2） during the rapid gaseous detonation reaction are discussed. Based on the experimental conditions and the Chapman-Jouguet theory, the Kruis model was introduced to simulate the growth characteristics of spherical TiO2 nanoparticles obtained under high pressure, high temperature and by rapid reaction. The results show that the numerical analysis can satisfactorily predict the growth characteristics of spherical TiO2 nanoparticles with diameters of 15-300 nm at different affecting factors, such as concentration of particles, reaction temperature and time, which are in agreement with the obtained experimental results. We found that the increase of the gas-phase reaction temperature, time, and particle concentration affects the growth tendency of spherical nanocrystal TiO2, which provides effective theoretical support for the controllable synthesis of multi-scale nanoparticles.
基金State Science and Technology CommitteeNational Natural Foundation of Science of China (19082012)+1 种基金 Chinese Academy of SciencesProject of National High Technology of China.
文摘The performance of combustion driver ignited by multi-spark plugs distributed along axial direction has been analysed and tested. An improved ignition method with three circumferential equidistributed ignitors at main diaphragm has been presented, by which the produced incident shock waves have higher repeatability, and better steadiness in the pressure, temperature and velocity fields of flow behind the incidence shock, and thus meets the requirements of aerodynamic experiment. The attachment of a damping section at the end of the driver can eliminate the high reflection pressure produced by detonation wave, and the backward detonation driver can be employed to generate high enthalpy and high density test flow. The incident shock wave produced by this method is well repeated and with weak attenuation. The reflection wave caused by the contracted section at the main diaphragm will weaken the unfavorable effect of rarefaction wave behind the detonation wave, which indicates that the forward detonation driver can be applied in the practice. For incident shock wave of identical strength, the initial pressure of the forward detonation driver is about 1 order of magnitude lower than that of backward detonation.
