Numerical simulation of subsonic and transonic flow flieds and aerodynamic characteristics of anti-tank intelligent mine

Anti-tank intelligent mine is a kind of new intelligent anti-tank bomb relying on high precision detector.It can effectively capture and damage targets with wind resistance coefficient and other factors affecting its flight characteristics under consideration.This article is based on the three-dimensional model of intelligent mine.To analyze its subsonic and transonic flow fields and the change law of aerodynamic force factor with the growth of the angle of attack,computational fluid dynamics software is used for intelligent mine flow field numerical calculation and the change law of pressure center.The results show that the large drag coefficient is conducive to the stability of scanning.Drastic changes of the flow field near the intelligent mine will disable its scanning movement.The simulation results can provide a reference for scanning stability analysis,overall performance optimization and appearance improvement.

Molecular tagging techniques and their applications to the study of complex thermal flow phenomena

This review article reports the recent progress in the development of a new group of molecule-based flow diagnostic techniques, which include molecular tag- ging velocimetry （MTV） and molecular tagging thermometry （MTT）, for both qualitative flow visualization of thermally induced flow structures and quantitative whole-field mea- surements of flow velocity and temperature distributions. The MTV and MTT techniques can also be easily combined to result in a so-called molecular tagging velocimetry and ther- mometry （MTV＆T） technique, which is capble of achieving simultaneous measurements of flow velocity and temperature distribution in fluid flows. Instead of using tiny particles, the molecular tagging techniques （MTV, MTT, and MTV＆T） use phosphorescent molecules, which can be turned into long-lasting glowing marks upon excitation by photons of appropriate wavelength, as the tracers for the flow veloc- ity and temperature measurements. The unique attraction and implementation of the molecular tagging techniques are demonstrated by three application examples, which include： （1） to quantify the unsteady heat transfer process from a heated cylinder to the surrounding fluid flow in order to exam- ine the thermal effects on the wake instabilities behind the heated cylinder operating in mixed and forced heat convec- tion regimes, （2） to reveal the time evolution of unsteady heat transfer and phase changing process inside micro-sized, icing water droplets in order to elucidate the underlying physics pertinent to aircraft icing phenomena, and （3） to achievesimultaneous droplet size, velocity and temperature measure- ments of ＂in-flight＂ droplets to characterize the dynamic and thermodynamic behaviors of flying droplets in spray flows.