Aircraft icing has long been a plague to aviation for its serious threat to flight safety.Recently,researches about a newly proposed deicing method based on Plasma Synthetic Jet Actuator(PSJA)have just started.To meet...Aircraft icing has long been a plague to aviation for its serious threat to flight safety.Recently,researches about a newly proposed deicing method based on Plasma Synthetic Jet Actuator(PSJA)have just started.To meet the requirements of in-flight deicing,structure of PSJA needs to be adjusted.This paper completed the detailed design and experimental validation of a novel plasma striker,which was a modified version of PSJA.Influences of mass of the moving part and rod shapes on the ice-breaking performances were also studied.Besides,a“conical-nosed rod configuration”was proposed.Its purpose was to ensure a good ice-breaking performance of the plasma striker on long ice,by generating a splitting failure.Results show that,though mass of the moving part was just several grams,ice-breaking performance was better when the mass was lighter.The rectangular rod could generate an elliptical circumferential crack,whose major axis was parallel to the direction of the long side of the rectangular rod.And the“conical-nosed rod”concept was verified to be able to generate a splitting crack which can spread completely to the far end of long ice,and the crack direction was parallel to edge line of the cone.In general,the plasma striker has the advantages of simple structure,low energy consumption,little harm to the flow field and the aircraft skin.Simulations will be carried out in future works to study in detail the working process of the plasma striker.展开更多
从适用范围、试样要求、设备要求、试验过程、试验结果评定等方面对现行三项冲击试验标准中的夏比冲击试验方法进行对比。对比发现:ASTM A 370只规定了夏比冲击V型缺口,ASTM E 23和GB/T 229规定的夏比冲击缺口类型包括V型缺口、U型缺口...从适用范围、试样要求、设备要求、试验过程、试验结果评定等方面对现行三项冲击试验标准中的夏比冲击试验方法进行对比。对比发现:ASTM A 370只规定了夏比冲击V型缺口,ASTM E 23和GB/T 229规定的夏比冲击缺口类型包括V型缺口、U型缺口以及无缺口试样;ASTM A 370和ASTM E 23规定摆锤刀刃半径为8 mm,而GB/T 229规定摆锤刀刃半径可使用2 mm和8 mm两种;GB/T 229在试样保温方面的要求更加详尽。展开更多
In order to present basic guidance for system calibration of split Hopkinson pressure bar(SHPB) with the special shape striker,wave characteristics and dynamic responses of SHPB under striker impact were analyzed.Stre...In order to present basic guidance for system calibration of split Hopkinson pressure bar(SHPB) with the special shape striker,wave characteristics and dynamic responses of SHPB under striker impact were analyzed.Stress generated by the special shape striker tends to have a half-sine waveform and has little wave dispersion during its propagation.Impact velocities of the special shape striker and peak values of generated stress still have linear relation but with a different coefficient from that of cylindrical strikers.From stress histories on the surfaces of the input bar impacted by the special shape striker off-axially and obliquely,it is found that the misalignment impacts usually trigger wave distortion and amplitude decrease,which can be used to identify the poor system adjustment.Finally,the system calibration of SHPB with the special shape striker can be classified into four steps:system adjustment,wave distortion identification,measurement calibration and transmission calibration,where the measurement calibration factor and transmission calibration factor are elaborated and redefined.展开更多
基金co-supported by the National Natural Science Foundation of China(No.12002377,52075538,11872374),the Open Fund of the Key Laboratory of IcingAnti/De-Icing(No.1901IADL20190401)+1 种基金the Natural Science Foundation of Hunan Province(No.2020JJ5670,2020JJ2031)China Postdoctoral Science Foundation(No.2019M652754).
文摘Aircraft icing has long been a plague to aviation for its serious threat to flight safety.Recently,researches about a newly proposed deicing method based on Plasma Synthetic Jet Actuator(PSJA)have just started.To meet the requirements of in-flight deicing,structure of PSJA needs to be adjusted.This paper completed the detailed design and experimental validation of a novel plasma striker,which was a modified version of PSJA.Influences of mass of the moving part and rod shapes on the ice-breaking performances were also studied.Besides,a“conical-nosed rod configuration”was proposed.Its purpose was to ensure a good ice-breaking performance of the plasma striker on long ice,by generating a splitting failure.Results show that,though mass of the moving part was just several grams,ice-breaking performance was better when the mass was lighter.The rectangular rod could generate an elliptical circumferential crack,whose major axis was parallel to the direction of the long side of the rectangular rod.And the“conical-nosed rod”concept was verified to be able to generate a splitting crack which can spread completely to the far end of long ice,and the crack direction was parallel to edge line of the cone.In general,the plasma striker has the advantages of simple structure,low energy consumption,little harm to the flow field and the aircraft skin.Simulations will be carried out in future works to study in detail the working process of the plasma striker.
文摘从适用范围、试样要求、设备要求、试验过程、试验结果评定等方面对现行三项冲击试验标准中的夏比冲击试验方法进行对比。对比发现:ASTM A 370只规定了夏比冲击V型缺口,ASTM E 23和GB/T 229规定的夏比冲击缺口类型包括V型缺口、U型缺口以及无缺口试样;ASTM A 370和ASTM E 23规定摆锤刀刃半径为8 mm,而GB/T 229规定摆锤刀刃半径可使用2 mm和8 mm两种;GB/T 229在试样保温方面的要求更加详尽。
基金Projects(50904079,50934006) supported by the National Natural Science Foundation of ChinaProject(2010CB732004) supported by the National Basic Research Program of China
文摘In order to present basic guidance for system calibration of split Hopkinson pressure bar(SHPB) with the special shape striker,wave characteristics and dynamic responses of SHPB under striker impact were analyzed.Stress generated by the special shape striker tends to have a half-sine waveform and has little wave dispersion during its propagation.Impact velocities of the special shape striker and peak values of generated stress still have linear relation but with a different coefficient from that of cylindrical strikers.From stress histories on the surfaces of the input bar impacted by the special shape striker off-axially and obliquely,it is found that the misalignment impacts usually trigger wave distortion and amplitude decrease,which can be used to identify the poor system adjustment.Finally,the system calibration of SHPB with the special shape striker can be classified into four steps:system adjustment,wave distortion identification,measurement calibration and transmission calibration,where the measurement calibration factor and transmission calibration factor are elaborated and redefined.
