Aim To investigate the effects of the incident orientation on the microwave attenuation. Methods Attenuation allowing microwave signal transmitting in an oblique or vertical direction through the solid propellant ex...Aim To investigate the effects of the incident orientation on the microwave attenuation. Methods Attenuation allowing microwave signal transmitting in an oblique or vertical direction through the solid propellant exhaust plume was computed, and the experiments were performed utilizing a lab scale solid rocket motor with a fully expanded nozzle. Results The predicted results accord well with the experimental results. Conclusion The microwave attenuation in the oblique path is greater than that in the vertical path.展开更多
To better understand potential pollutant formations during combustion of conventional hydrocarbon fuels blended with oxygenated fuels, detailed influences of ethanol as fuel additive on small polycyclic aromatic hydro...To better understand potential pollutant formations during combustion of conventional hydrocarbon fuels blended with oxygenated fuels, detailed influences of ethanol as fuel additive on small polycyclic aromatic hydrocarbons(PAHs) precursors, aldehydes, ketene and other important intermediate species in premixed fuel-rich low-pressure ethylene flames are distinguished among dilution, thermal and chemical effects of additives. Dominant effects of ethanol addition on each species are underlined respectively. Ethylene oxidation process is delayed when ethylene is substituted by ethanol. The influence of ethanol dilution and thermal effects on ethylene consumption are larger than chemical effects. CO mole fractions slightly decrease mainly as a result of dilution and thermal effects of added ethanol. The reductions in small PAHs precursors(acetylene and propargyl) are attributed to dilution and thermal effects of ethanol addition instead of chemical effects. The ethanol chemical effects promote formations of hazardous pollutants formaldehyde and acetaldehyde, and especially are responsible for the significant increase of acetaldehyde. C2H6, C4H2 and C4H4 mole fractions decrease in a similar way with acetylene and propargyl as ethanol is added. Ethanol used here only serves as a prototype of oxygenated additive, and identification method in this work is more universal which can be easily extended for analyzing other fuel blends of hydrocarbon and oxygenated fuels.展开更多
文摘Aim To investigate the effects of the incident orientation on the microwave attenuation. Methods Attenuation allowing microwave signal transmitting in an oblique or vertical direction through the solid propellant exhaust plume was computed, and the experiments were performed utilizing a lab scale solid rocket motor with a fully expanded nozzle. Results The predicted results accord well with the experimental results. Conclusion The microwave attenuation in the oblique path is greater than that in the vertical path.
基金supported by the National Natural Science Foundation of China(Grant No.51306091)the Jiangsu Provincial Natural Science Foundation of China(Grant Nos.BK20140034,BK20130758)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.30920140111005)the Jiangsu Provincial Project of"Six Talent Summit"(Grant No.2014-XNY-002)
文摘To better understand potential pollutant formations during combustion of conventional hydrocarbon fuels blended with oxygenated fuels, detailed influences of ethanol as fuel additive on small polycyclic aromatic hydrocarbons(PAHs) precursors, aldehydes, ketene and other important intermediate species in premixed fuel-rich low-pressure ethylene flames are distinguished among dilution, thermal and chemical effects of additives. Dominant effects of ethanol addition on each species are underlined respectively. Ethylene oxidation process is delayed when ethylene is substituted by ethanol. The influence of ethanol dilution and thermal effects on ethylene consumption are larger than chemical effects. CO mole fractions slightly decrease mainly as a result of dilution and thermal effects of added ethanol. The reductions in small PAHs precursors(acetylene and propargyl) are attributed to dilution and thermal effects of ethanol addition instead of chemical effects. The ethanol chemical effects promote formations of hazardous pollutants formaldehyde and acetaldehyde, and especially are responsible for the significant increase of acetaldehyde. C2H6, C4H2 and C4H4 mole fractions decrease in a similar way with acetylene and propargyl as ethanol is added. Ethanol used here only serves as a prototype of oxygenated additive, and identification method in this work is more universal which can be easily extended for analyzing other fuel blends of hydrocarbon and oxygenated fuels.
