Multi-scale Calculation of Rarefied Gas Transportation, Modern High-speed Aero-optics Mechanism and Methods
As for reentry spacecrafts, the direct simulation Monte - Carlo (DSMC) method is extended with the asymptotic preserving model based on mesoscopic physics model- Boltzmann equation, which enables the time step and the number of particles out of the limitation of Knudsen number. It therefore economically and accurately calculates the distribution of flow field within the reentry process from molecular zone, transition zone to the continuous flow zone.
This method is directly applied to the research of the modern high speed aero-optics mechanism including two aspects: One is the optic window design of optical imaging system of hypersonic aircraft. The other is a high speed flow visualization of PIV. These two applications are mutually support and traction. On one hand, the development of optical measurement techniques can promote the understanding of the flow field mechanism, thereby improving the design of the optic imaging system. On the other hand, aero-optics effects observed by the optic imaging system put forward new requirements for the understanding of the flow mechanism, thus promoting the development of optic flow diagnostic technology.
It can be seen that the important factors which integrated the two different applications in aero-optics are the recognition to the flow mechanism. This research will focus on the numerical algorithm to understand the flow mechanism, with the theoretical and experimental research on light field and flow field, thus gaining an insight into aero-optics coupling mechanism. Therefore, the overall goal of this study is to develop an efficient method and basic theory in order to promote the in-depth understanding of aero-optics flow mechanism.