  We present a "module-based hybrid" Uncertainty Quantification (UQ) framework
for general nonlinear multi-physics simulation. The proposed methodology,
introduced in [\hyperlink{ref1}{1}], supports the independent development of
each \emph{stochastic} linear or nonlinear physics module equipped with the
most suitable probabilistic UQ method: non-intrusive, semi-intrusive or
intrusive; and provides a generic framework to couple these stochastic
simulation components. Moreover, the methodology is illustrated using a common
"global" uncertainty representation scheme based on generalized polynomial
chaos (gPC) expansions of inputs and outputs. By using thermally-driven cavity
flow as the multi-physics model problem, we demonstrate the utility of our
framework and report the computational gains achieved.
