Combinatorial mechanics is the name given by
my collaborators and me to describe a special body of problems
that may be seen as dual to the standard question of mechanical
engineering: Instead of asking for a design to bear a given load,
we ask how a given design should be loaded. For example, one
canonical question is how to place loads on a structure so that
the resultant center of gravity lies as close as possible to a
given target point. This is the problem of stowing cargo in
planes, trucks, or ships.
Heuristics for balancing turbine fans, with S. V. Amiouny and J. H. Vande Vate;
Operations Research 48(4):591-602 (2000). A turbine is easier to balance if it has a number of
blades that is evenly divisible by 4.