click here for News and Media coverage 

modeling forest fire by a paperburning experiment: a realization of the interface growth mechanism,
click to view pdf
Jun Zhang, Y.C. Zhang, P. Alstrom and M. T. Levinsen
Physica A, 189, 383 (1992)

Abstract:
We present an experiment on the propagation front of a flameless fire on a thin piece of paper. We find that fire fronts on a piece
of paper follow quite well selfaffine scaling statistics, with the roughening exponent \chi around 0,70, well above the value 1/2
in the theoretical interface growth model using Gaussian noise. This discrepancy may be due to an anomalously singular behavior of
the noise distribution, consistent with some recent studies.

stochastic transition intermittency in pipe flows: experiment and model,
click to view pdf
Jun Zhang, D. Stassinopoulos, P. Alstrom and M. T. Levinsen
Physics of fluids, 6, 1722 (1994)

Abstract:
New experimental results at the onset of turbulence in a gravitydriven pipe flow are presented, and a simple phenomenological model
is introduced to describe the intermittent behavior observed. In this model slugs are stochastically produced at the pipe inlet, the the
decrease in velocity due to tuebulent friction is taken into account. The present approach shows that stochastic arguments accounts well
for several experimental observations at low intermittency factors. In particular, it is shown that special intermittency routes to
chaos are not needed to explain the exponentially decaying inverse cumulative distribution of laminar times.

periodic states in intermittent pipe flows: experiment and model,
click to view pdf
D. Stassinopoulos, J. Zhang, P. Alstrom and M. T. Levinsen
Physical Review E, 50, 1189 (1994)

Abstract:
We report an experimental study of a transition to periodic intermittency in pressuredriven pipe flows. The transition is preceded by a
rapid increase of the intermittency factor with pressure. To model intermittent pressuredriven flows, we introduce a general model, where
a fifthorder GinzburgLandau equation is coupled with a pressurevelocity relation that takes into account the frictional effect of the
turbulence on the flow velocity. We determine the phase diagram and show that the model gives a qualitative understanding of the transition
to periodic intermittency.

click here for News and Media coverage 
