Early Attempts With A Square Lattice
In papers published in 1973 and 1976, Hardy, Pomeau and de Pazzis introduced the first Lattice Boltzmann model, which is called the HPP model after the authors. In this model, the lattice is square, and particles can move to any of the four sites whose cells share a common edge. Particles cannot move diagonally.
If two particles collide head-on, for example a particle moving to the left meets a particle moving to the right, the outcome will be two particles leaving the site at right angles to the direction they came in.
The HPP model lacked rotational invariance, which made the model highly anisotropic. This means for example, that the vortices produced by the HPP model are square-shaped.
Read more about this topic: Lattice Gas Automaton
Famous quotes containing the words early, attempts and/or square:
“Everyone in our culture wants to win a prize. Perhaps that is the grand lesson we have taken with us from kindergarten in the age of perversions of Dewey-style education: everyone gets a ribbon, and praise becomes a meaningless narcotic to soothe egoistic distemper.”
—Gerald Early (b. 1952)
“Museums, museums, museums, object-lessons rigged out to illustrate the unsound theories of archaeologists, crazy attempts to co-ordinate and get into a fixed order that which has no fixed order and will not be co-ordinated! It is sickening! Why must all experience be systematized?... A museum is not a first-hand contact: it is an illustrated lecture. And what one wants is the actual vital touch.”
—D.H. (David Herbert)
“If the physicians had not their cassocks and their mules, if the doctors had not their square caps and their robes four times too wide, they would never had duped the world, which cannot resist so original an appearance.”
—Blaise Pascal (1623–1662)