Abstract:
The physical grounds of droplet breakdown in a flow behind a transient shock wave in accordance with one of possible sheet stripping mechanisms (shedding of a liquid boundary layer) are considered. The analysis is performed on the basis of data of high-speed shadowgraphy of the droplet behavior behind the shock wave in the range of the Weber numbers We = 200–2200, measurements of the breakdown induction period, and registration of the ablation character. The condition of instability of the liquid surface by the sheet stripping mechanism and the criterion of interface breakdown are formulated with the use of parameters of an adjoint boundary layer in the fluid. On this basis and with due allowance for previous investigations, a dependence of the delay of droplet breakdown by this mechanism on the fluid characteristics and flow parameters is derived.
Keywords:aerodynamic breakdown of droplets, shock waves, mechanism of liquid sheet stripping, parametric analysis.