Numerical pressure threshold method to simulate cement paste slump flow

摘要

In this study, we propose a novel pressure threshold method for the Bingham numerical model and apply the method to simulate cement paste slump flow. Calculation is divided into three steps. First, the cement paste is computed as a Newtonian fluid. An advection step and a non-advection step are computed in sequence. In the non-advection step, the fractional steps are implemented to calculate viscous, gravity, and pressure terms. Second, a pressure threshold judgment is used to modify the motion state of cement paste cells. Third, an iterative correction, which is an iterative process to determine the precise unyielded (rigid) and yielded (fluid) regions, is conducted for the Bingham computational model. The volume/surface integrated average-based multi-moment method scheme is used to compose a new finite volume formula for solving general fluid dynamic problems. The tangent of hyperbola for interface capturing approach is used to capture free boundaries in multi-fluid simulations. The computational modeling enables accurate simulation of the flow process of cement paste to analyze different mix designs and to evaluate the workability of cement paste. The proposed methodology is relevant to computational mechanics with applications in cement flow simulations.