Evolution of Rayleigh-Taylor instability under interface discontinuous acceleration induced by radiation

Area of Science:

• Fluid dynamics
• Plasma physics
• Astrophysical phenomena

Background:

• Rayleigh-Taylor instability (RTI) is crucial in engineering and natural phenomena.
• Previous studies of interface discontinuous acceleration (IDA) RTI were limited to the linear stage.

Purpose of the Study:

• To investigate the complete evolution of IDA-RTI beyond the linear stage.
• To establish a theoretical framework and numerical simulations for IDA-RTI.

Main Methods:

• Numerical simulations of IDA-RTI evolution.
• Theoretical analysis introducing an effective acceleration (g_{eff}^{*}).

Main Results:

• IDA-RTI is equivalent to classical RTI with an effective acceleration, g_{eff}^{*}
• IDA-RTI occurs if and only if g_{eff}^{*} > 0, allowing instability when fluids have equal density or when heavy fluid supports light fluid.
• Quasisteady bubble and spike velocities were accurately predicted and validated against simulations.

Conclusions:

• The study provides a comprehensive understanding of IDA-RTI, extending beyond linear analysis.
• The effective acceleration criterion simplifies the conditions for IDA-RTI occurrence.
• Accurate prediction of velocities offers valuable insights for related physical systems.