Since flight accidents due to aircraft icing occur from time to time,this paper proposes an array of impact rod-type plasma synthetic jet de-icing methods for aircraft icing problems.The impact rod-type plasma synthet...Since flight accidents due to aircraft icing occur from time to time,this paper proposes an array of impact rod-type plasma synthetic jet de-icing methods for aircraft icing problems.The impact rod-type plasma synthetic jet actuator(PSJA)is based on the traditional PSJA with an additional impact rod structure for better de-icing in the flight environment.In this work,we first optimize the ice-breaking performance of a single-impact rod-type PSJA,and then conduct an array of impact rod-type plasma synthetic jet ice-breaking experiments to investigate the relationship between crack expansion and discharge energy,ice thickness and group spacing.The results show that the impact force and impulse of a single-impact rod-type PSJA are proportional to the discharge energy,and there exists a threshold energy Qmin for a single actuator to break the ice,which is proportional to the ice thickness.Only when the discharge energy reaches above Qmin can the ice layer produce cracks,and at the same time,the maximum radial crack length produced during the ice-breaking process is proportional to the discharge energy.When the ice is broken by an array of impact rod PSJAs,the discharge energy and group spacing together determine whether the crack can be extended to the middle region of the actuator.When the group spacing is certain,increasing the energy can increase the intersection of cracks in the middle region,and the ice-fragmentation degree is increased and the ice-breaking effect is better.At the same time,the energy estimation method of ice breaking by an array of impact rod-type PSJAs is proposed according to the law when a single actuator is breaking ice.展开更多
The collision of a supercooled water droplet with a surface result an object creates ice accretion on the surface. The icing problem in any cold environments leads to severe damages on aircrafts, and a lot of studies ...The collision of a supercooled water droplet with a surface result an object creates ice accretion on the surface. The icing problem in any cold environments leads to severe damages on aircrafts, and a lot of studies on prevention and prediction techniques for icing have been conducted so far. Therefore, it is very important to know the detail of freezing mechanism of supercooled water droplets to improve the anti-and de-icing devices and icing simulation codes. The icing mechanism of a single supercooled water droplet impacting on an object surface would give us great insights for the purpose. In the present study, we develop a dual-luminescent imaging technique to measure the time-resolved temperature of a supercooled water droplet impacting on the surface under different temperature conditions. We apply this technique to measure the exact temperature of a water droplet, and to discuss the detail of the freezing process.展开更多
基金financially supported by National Natural Science Foundation of China(No.12002384)National Key Laboratory Foundation of China(No.614220220200107)+1 种基金National Science and Technology Major Project of China(No.J2019-II-0014-0035)Academician Workstation F0undation of the Green Aerotechnics Research Institute of Chongqing Jiaotong University(No.GATRI2020C06003)。
文摘Since flight accidents due to aircraft icing occur from time to time,this paper proposes an array of impact rod-type plasma synthetic jet de-icing methods for aircraft icing problems.The impact rod-type plasma synthetic jet actuator(PSJA)is based on the traditional PSJA with an additional impact rod structure for better de-icing in the flight environment.In this work,we first optimize the ice-breaking performance of a single-impact rod-type PSJA,and then conduct an array of impact rod-type plasma synthetic jet ice-breaking experiments to investigate the relationship between crack expansion and discharge energy,ice thickness and group spacing.The results show that the impact force and impulse of a single-impact rod-type PSJA are proportional to the discharge energy,and there exists a threshold energy Qmin for a single actuator to break the ice,which is proportional to the ice thickness.Only when the discharge energy reaches above Qmin can the ice layer produce cracks,and at the same time,the maximum radial crack length produced during the ice-breaking process is proportional to the discharge energy.When the ice is broken by an array of impact rod PSJAs,the discharge energy and group spacing together determine whether the crack can be extended to the middle region of the actuator.When the group spacing is certain,increasing the energy can increase the intersection of cracks in the middle region,and the ice-fragmentation degree is increased and the ice-breaking effect is better.At the same time,the energy estimation method of ice breaking by an array of impact rod-type PSJAs is proposed according to the law when a single actuator is breaking ice.
文摘The collision of a supercooled water droplet with a surface result an object creates ice accretion on the surface. The icing problem in any cold environments leads to severe damages on aircrafts, and a lot of studies on prevention and prediction techniques for icing have been conducted so far. Therefore, it is very important to know the detail of freezing mechanism of supercooled water droplets to improve the anti-and de-icing devices and icing simulation codes. The icing mechanism of a single supercooled water droplet impacting on an object surface would give us great insights for the purpose. In the present study, we develop a dual-luminescent imaging technique to measure the time-resolved temperature of a supercooled water droplet impacting on the surface under different temperature conditions. We apply this technique to measure the exact temperature of a water droplet, and to discuss the detail of the freezing process.
