Abstract
This paper presents a microwave approach to investigate the wake velocity distribution of hypervelocity projectile. The ballistic range measurement is carried out to model the transport of hypervelocity object on the ground. An X-band horn antenna sends a continuous sinusoidal wave with f c = 8.7 GHz to the hypervelocity object and detects the reflected signal. The continuous wavelet transform is utilized to obtain the Doppler frequency shift, and the wake velocity is calculated based on the theory of the Doppler effect. The validity of this experiment is confirmed by comparing the measured projectile velocity with that achieved by a laser-based velocity meter. As a contactless method, this approach does not interfere with the wake flow field. Therefore, the velocity distribution achieved in this paper exhibits better accuracy compared with that obtained from other contact approaches.
Highlights
The hypervelocity projectile generates plasma sheath around its body and leaves wake flow field behind
It is easy to see that three plots exhibit similar frequency distribution when the target flies through and the Doppler frequency shift caused by the projectile itself is much higher than that caused by the wake
In summary, this paper presents a contactless approach to obtain the wake velocity distribution of hypervelocity projectile in ballistic range measurement
Summary
The hypervelocity projectile generates plasma sheath around its body and leaves wake flow field behind. As a frequently used facility in aerodynamic research, has been widely applied to model the transport of hypervelocity object or reentering spacecraft under ambient pressure in ground test [1]. Later in 1970, they compared the sphere wake velocity achieved by sequential spark method with that measured by electrostatic probe, hot wire and sequential schlieren approaches [4]. Compared with the sequential schlieren technique, the rest methods are contact approaches that may destroy the wake flow field and only record the local wake velocity. The velocity measured with sequential schlieren method is relatively lower than that achieved with other three as it measures the average velocity over the whole wake
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
