Presented herein is an experimental study on the combustion of B4C/KNO3 binary pyrotechnic system.Combustion products were tested using X-ray diffraction(XRD),scanning electron microscopy(SEM),and energy dispersive sp...Presented herein is an experimental study on the combustion of B4C/KNO3 binary pyrotechnic system.Combustion products were tested using X-ray diffraction(XRD),scanning electron microscopy(SEM),and energy dispersive spectrometer(EDS).According to the results of tests and CEA calculation,the combustion reaction equation was established.The flames and burning rates were recorded by a high speed camera and a spectrophotometer.The effect of B4C particle size on the thermal sensitivity of B4C/KNO3 was investigated by differential scanning calorimetry(DSC)techniques.In addition,a reliable method for calculating the flame temperature was proposed.Based on the results of experiments,the combustion reaction mechanism was briefly analyzed.The burning rate,flame temperature and thermal sensitivity of B4C/KNO3 increase with the decrease of B4C particle size.The mass ratio of B4C/KNO3 has a great effect on combustion properties.Oxidizer-rich compositions have low flame temperatures,low burning rates,and provide green light emission.The combustion reactions of fuel-rich compositions are vigorous,and the B4C/KNO3 with mass ratio of 25:75 has the highest burning rate and the highest flame temperature.展开更多
It is a valuable issue to explore whether a flame can radiate microwaves,in spite of the electric field formed in the flame.Presented herein is an experimental study on a series of flames with millimeterwave radiation...It is a valuable issue to explore whether a flame can radiate microwaves,in spite of the electric field formed in the flame.Presented herein is an experimental study on a series of flames with millimeterwave radiation in the combustion of pyrotechnic films.The pyrotechnic films were composed of ultrafine red phosphorus(P),sodium nitrate(NaNO_3),Polyvinyl Alcohol(PVA) and some additives such as chopped carbon fibers(CFs) and aluminized glass fibers(GFs).The combustion temperatures and millimeter-wave radiation signals of the flames were measured,the millimeter-wave emissivity and spectral radiant exitance were calculated to describe the millimeter-wave radiation intensity.The results demonstrate that the flame of the pyrotechnic films based on P/NaNO_3/CFs can radiate millimeter waves,and different materials and their proportion have a great effect on the millimeter-wave radiation intensity.展开更多
基金The support for this work was provided by the National Natural Science Foundation of China(Project No.51676100).
文摘Presented herein is an experimental study on the combustion of B4C/KNO3 binary pyrotechnic system.Combustion products were tested using X-ray diffraction(XRD),scanning electron microscopy(SEM),and energy dispersive spectrometer(EDS).According to the results of tests and CEA calculation,the combustion reaction equation was established.The flames and burning rates were recorded by a high speed camera and a spectrophotometer.The effect of B4C particle size on the thermal sensitivity of B4C/KNO3 was investigated by differential scanning calorimetry(DSC)techniques.In addition,a reliable method for calculating the flame temperature was proposed.Based on the results of experiments,the combustion reaction mechanism was briefly analyzed.The burning rate,flame temperature and thermal sensitivity of B4C/KNO3 increase with the decrease of B4C particle size.The mass ratio of B4C/KNO3 has a great effect on combustion properties.Oxidizer-rich compositions have low flame temperatures,low burning rates,and provide green light emission.The combustion reactions of fuel-rich compositions are vigorous,and the B4C/KNO3 with mass ratio of 25:75 has the highest burning rate and the highest flame temperature.
基金support for this work was provided by the National Natural Science Foundation of China(Project No.51676100)。
文摘It is a valuable issue to explore whether a flame can radiate microwaves,in spite of the electric field formed in the flame.Presented herein is an experimental study on a series of flames with millimeterwave radiation in the combustion of pyrotechnic films.The pyrotechnic films were composed of ultrafine red phosphorus(P),sodium nitrate(NaNO_3),Polyvinyl Alcohol(PVA) and some additives such as chopped carbon fibers(CFs) and aluminized glass fibers(GFs).The combustion temperatures and millimeter-wave radiation signals of the flames were measured,the millimeter-wave emissivity and spectral radiant exitance were calculated to describe the millimeter-wave radiation intensity.The results demonstrate that the flame of the pyrotechnic films based on P/NaNO_3/CFs can radiate millimeter waves,and different materials and their proportion have a great effect on the millimeter-wave radiation intensity.
