Numerical investigation of microstructural damage during kneading of wheat dough

Abstract

Abstract The focus of this study is the kneading process of wheat dough. As an idealized kneader geometry, the eccentric cylinder benchmark geometry was considered. This work presents the first computational study in which the dough model developed by Tanner's group (R.I. Tanner, F. Qi, S.-C. Dai, Bread dough rheology and recoil: I. Rheology. J. Cereal Sci. 148 (1) (2008) 33–40) was solved for inhomogeneous flow. The values of the model parameter were obtained from small amplitude oscillatory shear, stress relaxation, start-up of simple shear, and compression experiments. To computationally evaluate the damage function, a time evolution equation had to be implemented for the Cauchy–Green strain tensor. The flow problem was numerically solved using a finite volume procedure available in the software OpenFOAM package rheoTool. As a result of the rapid decrease in accumulated strain, filaments of low damage were formed near the outer diverging part of the cylinder, convected downstream and further extended, and eventually broken down. Planar extension had the most destroying effect on the microstructure. In the future, we will investigate three-dimensional free-surface flows in industrial kneading geometries.