Effects of molecular diffusivity on shock-wave structures in monatomic gases

Area of Science:

• Fluid Dynamics
• Non-equilibrium Thermodynamics
• Computational Physics

Background:

• Accurate shock-wave profile description is crucial for understanding gas dynamics.
• Existing hydrodynamic models face limitations in predicting shock structure, especially at higher Mach numbers.
• Constitutive equations derived from continuum flow models offer a promising avenue for improved accuracy.

Purpose of the Study:

• To investigate and improve the description of shock-wave profiles using advanced hydrodynamics models.
• To identify constitutive equations that enhance the prediction of shock structure in monatomic gases.
• To validate the model by including temperature profiles and ensuring non-negative entropy production.

Main Methods:

• Utilized constitutive equations from a thermomechanically consistent Burnett regime continuum flow model.
• Employed a finite difference global solution (FDGS) scheme for numerical computations.
• Extended analysis to include temperature profiles and entropy production, beyond traditional density profiles.

Main Results:

• Achieved better agreement for shock structure parameters in monatomic gases (Mach 1.0-11.0).
• Demonstrated improved accuracy compared to bivelocity hydrodynamics and Boltzmann equation expansion methods.
• Successfully incorporated temperature profiles and confirmed non-negativity of entropy production.

Conclusions:

• The developed hydrodynamic model with new constitutive equations provides a more accurate description of shock-wave profiles.
• This approach offers significant improvements over existing methods, particularly for predicting shock structure in monatomic gases.
• The inclusion of temperature and entropy production provides a more comprehensive understanding of shock phenomena.