Motion behavior of non-Newtonian fluid-solid interaction foods

Abstract

The operation object of meal-assisting robots is food with unique rheological properties and complex fluid-solid interactions, which brings great difficulties in the food fetching rate. In this paper, non-Newtonian fluid-solid coupled foods containing thickening gums were investigated by a combination method of experiment and simulation. The viscosity and density of the non-Newtonian fluid were measured by rotational viscometer and densitometer, respectively. The power law model and the Herschel-Bulkley model were used to characterize the shear rheological properties of the fluid foods, respectively. The effects of inclination angle, fetching velocity, and thickening gums on the fetching rate and motion behavior were investigated by a combination method of an explicit algorithm coupling Euler-Lagrange to characterize the fluid-solid interaction relationship. The results show that the non-Newtonian fluid has a higher apparent viscosity at low shear rates for XG: GG = 1:1, however, it has a higher apparent viscosity at high shear rates for XG: GG = 1:2. The consistency index decreases with the temperature increase. It had a larger yield stress for XG: GG = 1:1, which indicated a longer retention of the gel elastic phase when the same shear force was applied. When XG: GG = 1:1, the density of the thickening solution decreases the fastest with the temperature increase. The displacement and velocity of solid particles decrease with the XG proportion increase. This study has reference value for the meal-assisting robot to improve the food fetching rate.