Mathematical modelling of vegetable oil plunger extraction

The research relates to studying a mixture of grained oilseeds saturated with oil and deformed with plunger molding. Mathematical simulations aim was determination of oil extraction velocity under the set loading conditions. Current statement treats processed material as biphasic mixture. Oilseed cake presented the first phase, which also was material’s porous skeleton. Vegetable oil filling the porous skeleton was the second phase of the mixture. Multiphase dynamics approach was applied in current research for material behavior description. Balance equations were set up for each mixture components. Interfacial volumetric force introduction modelled filtration of liquid. According to former researches, viscous liquid model described properties of porous skeleton as well as properties of vegetable oil. Porous skeleton viscosity assumed to be pressure dependent. Numerical solution of problem was carried out in two-dimensional statement for expression chamber middlesection using finite element approach. The primary variables were constituent’s velocity and pressure fields. Current study used cake pressure dependent porosity model that is common in porous media mechanics. Computational domain discretization was carried out using nine-node rectangular finite elements with linear and quadratic approximation for pressure and velocity fields respectively. Oil saturation distribution along expression chamber height obtained in numerical experiments demonstrates nonlinearity under high external loads. Moreover, the study investigated porosity changes influence on vegetable oil flow during expression.