Non-Newtonian Flows

Everyday fluids such as blood, ketchup, toothpaste, shampoo, paint and lotion have complex rheology with varying viscosities. FLOW-3D models such fluids with non-Newtonian viscosities that are strain and/or temperature dependent. Shear and temperature dependent viscosities are described with either Carreau, the power law functions or simply through a tabular input. Time-dependent or thixotropic behavior, characteristic of some polymers, ceramic and semi-solid metals, can also be simulated.

Hand Lotion Pump

Velocity contours as lotion pulsates through nozzle

Hand lotion pumps are common, however, they are often associated with several design issues. It is important for the pump to work effectively without trapping air voids and generate a continuous stream of lotion. A good design would require less effort and would ideally direct the lotion to a desired place. FLOW-3D’s Moving Objects model is used to simulate the two balls that are used to regulate and constrain lotion within the pump. Several design variables can easily analyzed within the same stationary structured mesh.

FLOW-3D’s TruVOF method accurately captures the pulsating lotion as the ball regulates the frequency of dispensing lotion.

Vertical cross section: Pressure contours showing operating pump

Shown here is a cross section of a hand lotion pump with transient pressure contours, resulting in back pressure and air voids during the pumping action. The void within the pump nozzle and upper section is well captured, allowing designers to eliminate inefficiency.