Shock velocity increase due to a heterogeneity produced by a two-gas layer

Area of Science:

• Fluid Dynamics
• Shock Wave Propagation
• Gas Dynamics

Background:

• Understanding shock wave behavior in complex media is crucial for various applications.
• Previous studies often simplified gas mixtures, limiting applicability to real-world scenarios.

Purpose of the Study:

• To investigate shock propagation in a two-gas layer confined geometry.
• To compare shock dynamics in heterogeneous versus homogeneous equivalent density mixtures.
• To analyze shock front shape, velocity, and refraction patterns.

Main Methods:

• Shock tube experiments were conducted.
• Two-dimensional Eulerian numerical calculations were performed.
• Molecular diffusion was incorporated into numerical models.

Main Results:

• Shocks propagated faster in the two-gas layer than in the homogeneous mixture.
• The shock front became curved in the two-gas layer, featuring a triple point near the wall.
• A correlation was observed between shock front curvature angle and velocity increase.
• Irregular shock front refraction patterns at the gas interface were sustained.

Conclusions:

• Shock propagation is significantly modified by gas layering, leading to increased velocity and altered front dynamics.
• Numerical simulations incorporating molecular diffusion accurately replicate experimental observations.
• The findings provide insights into shock wave behavior in non-uniform gas environments.