飞行员头盔夜视镜系统气流吹袭性能研究

开展飞行员头盔夜视镜系统的高速气流吹袭试验，研究其气动特性和作用在人体颈椎上的力，评价其对弹射救生安全性的影响，为头盔夜视镜系统的设计和使用提供依据。采用高速气流吹袭台（敞开式风洞）吹袭的试验方法，将弹射座椅固定在吹袭台喷口前的台架上，试验假人（HYBRID Ⅱ型假人）端正地放置在弹射座椅上，试验假人穿抗荷服，佩戴头盔、夜视镜、供氧面罩。以850 km/h的吹袭速度作为试验的起点，按照试验设计确定的原则依次调整吹袭速度。夜视镜分下位（工作）和上位（非工作）2个状态进行试验，用高速摄像机记录头盔夜视镜在吹袭时的佩戴状态，测量试验假人颈椎下端的力和力矩。高速摄像机、力和力矩测量系统用高速气流吹袭台设定的时间基准同步测量。共进行了10发试验，其中5发试验夜视镜从头盔上吹脱，5发未吹脱；获得了各次试验中假人颈椎的受力曲线及夜视镜吹脱的时刻和轨迹。按照试验合格判据，吹袭速度均未超过850 km/h。头盔加装夜视镜后，相比头盔不加装夜视镜，气流吹袭性能下降，吹袭速度800 km/h以上颈椎力矩超标，700 km/h为临界点，600 km/h合格。建议将头盔夜视镜系统的气流吹袭性能包线限制在600 km/h以内。 

Windblast performance of pilot helmet-mounted night vision goggle system

High-speed windblast experiments of pilot helmet-mounted night vision goggle system were carried out to study its aerodynamic characteristics and the forces on human cervical vertebra, and to evaluate the influence on the safety of ejection life-saving, so as to provide a basis for the design and use of helmet-mounted night vision goggle system. The test was carried out by an open wind tunnel called high-speed windblast test platform. The ejection seat was fixed in front of the tunnel nozzle, and the HYBRID Ⅱ dummy was fastened on the ejection seat with anti-gravity suit, helmet with night vision goggles and oxygen mask. Taking 850 km/h as the starting speed, we adjusted the speed in turn according to the principle determined by the experimental design. The night vision goggles had lower and upper state, which corresponded to working and non-working state respectively. The helmet-mounted night vision goggles wearing state during the windblast was recorded by a high-speed camera, and the force and torque of the lower cervical vertebra of the test dummy were measured. The high-speed camera and force and torque measuring system used the time benchmark set by the windblast test system to achieve synchronous measurement. A total of ten tests were carried out, in five of which the night vision goggles were blown off the helmet, and in another five of which they were not. The force and torque curves of the cervical vertebra, and the time and trajectory of the goggles blown off were obtained in each test. According to the test criterion, the blowing speeds do not exceed 850 km/h. Compared with the helmet without night vision goggles, the windblast performance of helmet-mounted night vision goggles is relatively reduced. The cervical torque exceeds the standard when the speed is more than 800 km/h, 700 km/h is the critical point and 600 km/h is qualified. It is recommended to limit the windblast performance envelope of helmet-mounted night vision goggle system to 600 km/h.