A more complex initial setup could be constructed for experimental or numerical studies. Many distinct initial interfacial perturbations may be set up: the standard and inverted chevron shapes, enlarged double-bump, V, W, and sawtooth. The so-called "inclined shock tube" method of perturbing the fluid interface is created by inclining the shock tube with respect to the gravitational field. Tilted tank experiments consist of a tank filled with light fluid above heavy, which is then tilted onto one side of the apparatus. These experiments provide two-dimensional data for mix model development.