A multiply-twisted helix, in which a one-dimensional array of components is twisted, producing a helix which if twisted itself produces a doubly-twisted helix, and so on, in which there are couplings between adjacent rounds of helices, was investigated using a cellular automaton and the spectral...

We present theory and experiments on the circular hydraulic jump in the stationary regime. The theory can handle the situation in which the fluid flows over an edge far away from the jump. In the experiments the external height is controlled, and a series of transitions in the flow structure...