液滴在运动气流中的变形和破碎问题在人们的日常生活和生产活动中广泛存在。液滴破碎过程对农林喷雾、工业生产中的表面喷涂以及内燃或火箭发动机中燃料的雾化与燃烧等均具有重要影响。本项目申请拟通过实验、理论分析和数值模拟相结合的方法，研究粘弹性液滴在气流作用下的变形、破碎过程、主要破碎模态和相应破碎机理。分析各参数（如Weissenberg 数、Weber 数、雷诺数、马赫数等）对液滴变形、破碎过程和破碎模态的影响规律，着重分析液滴粘弹性效应的影响。确定影响粘弹性液滴破碎过程和破碎模态的关键控制参数，并在相应参数空间中给出粘弹性液滴的临界破碎曲线。在此基础上，采用实验和数值模拟相结合的方法，分析激波作用下粘弹性液滴的破碎规律及相应破碎机理。

Aero-breakup of liquid drop occurs in various technical process, environmental science and everyday life, such as coatings, internal-combustion engines (for land-based power production), injection of gelled hypergolic fuels (for aero-propulsion). For each of these applications to work.efficiently, a certain droplet size is indispensable. The necessity for drops of a certain size clearly demonstrates the need to determine the conditions which lead to drop breakup and, consequently, to eventual drop sizes. In this proposal, the deformation and breakup of viscoelastic drops are studied based on both experimental test and theoretical analysis. The breakup process, breakup mode and corresponding instability mechanisms are main concerned. The influence of various parameters, e.g. Weissenberg number, Weber number, Ohnesorge number, Reynolds number and Mach number, on the droplet breakup are examined comprehensively. The key parameters, which dominate the breakup mode of the droplet, are classified. The critical curves, which delineate each breakup mode in the parameter space, are also presented. Furthermore, the characteristics of viscoelastic droplet breakup caused by shock wave are also examined by numerical simulation methods.