A study of pseudopotential lattice Boltzmann method with applications to thermal bubble nucleation
Abstract
The nature of the work dealt with in this thesis is mathematical modelling of multiphase
flows. The main objective of this doctoral work was to study multiphase lattice
Boltzmann models (LBM) and to develop an advanced pseudopotential model.
Specifically, advanced thermal lattice Boltzmann models were applied to study bubble
nucleation in nucleate pool boiling at subatmospheric pressures. The numerical
investigations carried out as part of this work follow the format well-established in the
literature and allow further studies in more complex geometries.
The work carried out contributes to current discussions in the literature and fulfils the
recommendations of a number of authors. Fluid-fluid interactions in the Yuan-Schaefer,
multipseudopotential interaction and piecewise linear equation of state methods were
investigated. Multipseudopotential interaction was established as a practicable method of
multiphase simulations by combination with the multiple relaxation time collision
operator, surface tension modification methods and with modified temperature double
distribution function and hybrid (4th order Runge-Kutta) thermal LBM models.
Thermal LBM simulations were found to agree well with experimental findings on the
influence of subatmospheric pressure on bubble nucleation. It was found that as pressure
is lowered in LBM simulations the size of bubbles nucleated increases, according to
bubble diameter ~ pressure-1
, with results falling in between experimental data for brass
and stainless steel tubes