Introduction: The classical kinetic theory models were the obvious choice for early DSMC work, but were found to have serious shortcomings that have been overcome by phenomenological models that have been introduced in the context of the DSMC method.
For elastic collisions, the classical hard sphere and Maxwell molecules lead
to fixed and unrealistic temperature variations of the coefficient of viscosity and
should not be used for problems that involve large variations in temperature. The
Classical kinetic theory did not lead to any useful models for inelastic collisions.
For example, the rough sphere model retains the deficiencies of the hard sphere
model with regard to the transport properties, it is unable to deal with the quantum
effects that cause most gases to have fewer than three rotational degrees of freedom
and has a fixed and unrealistically fast rotational relaxation time. This problem
was solved in the context of the DSMC method by the introduction of the Larsen-
New molecular models for DSMC
The extension of the quantum vibration model to include dissociation was first presented
at the RGD26 meeting as a physically realistic extension of the model. The results
were so encouraging that an attempt was made to develop phenomenological models for
the other reactions. That for the endothermic exchange and chain reactions is analogous
to the dissociation condition, but has only recently evolved to a fully satisfactory
state. The new chemisty model was termed the Quantum-
The implementation of the Q-
Unlike the TCE model, The Q-
Unlike the TCE model, the Q-
The latest developments with regard to Q-
NOTE: There is a typo in the text following Eq. (5) in that the symmetry factor is 1 for unlike and 2 for like molecules. Also, in the first paragraph in the second column of the following page, imax should be i*.
The supplementary material for the paper included an interactive graphical program
for the evaluation of the parameters that ensure that the Q-