The apparent viscosity for the flat plate control matches the
rated viscosity of the fluid independent of the direction of motion,
up until viscous heating effects are observed. The surface textures
reduce the apparent viscosity from the flat plate reference independent
of the direction of motion, which matches results given
by Johnston et al. [8] and Qiu and Khonsari [13] for symmetric
textures. Smaller gaps experience a larger change in apparent
viscosity.