Use of the dimensional multiphase lattice Boltzmann method to simulate the Rayleigh-Taylor instability

Resumo

Recently, the authors have proposed a modification of the traditional lattice Boltzmann method (LBM) that dispends the need of the variables convertion to the lattice space. Thus, all variables are used directly in physical units. This modification simplify the implementation of real problems. Considering this model, in this work we discuss a validation test of a multiphase problem: the Rayleigh-Taylor instability. One of the experiments performed by Wadell et al. (2001) is reproduced and the numerical results are compared with the experimental data. Our results showed a good accuracy, concerning both the amplitude of the instability and the shape of the multiphase structures. Next, the terminal velocity of the structures was compared with theoretical predictions from the literature, showing also a good agreement. The results evidenced the capability of the method to deal with multiphase problems in real operational conditions, as all the comparisons with both experimental and theoretical predictions showed a good accuracy.