5 papers
Static compliance and directional instability in indefinite conformation states
Yuan Yu
A conformation tensor is positive definite for every physically realizable polymer microstructural state. Numerical discretization can move the conformation tensor outside the posi…
Loss of positive definiteness is a symptom, not the cause, of high-Weissenberg-number breakdown
Yuan Yu, Lanjin Lian, Feiyang Chu
Numerical breakdown at high Weissenberg number is often attributed to loss of symmetric positive definiteness (SPD) of the conformation tensor. That conclusion follows from Maxwell…
Purified Two-Relaxation-Time Lattice Boltzmann Method: Removing Ghost Modes from TRT for Enhanced Stability
Yuan Yu, Yaolong Yu, Yuting Zhou +3
The two-relaxation-time (TRT) lattice Boltzmann model is widely adopted for its simplicity and tunable boundary accuracy. However, its collision operator relaxes the full symmetric…
An improved lattice Boltzmann method with a novel conservative boundary scheme for viscoelastic fluid flows
Yuan Yu, Siwei Chen, Lei Wang +2
The high Weissenberg number problem has been a persistent challenge in the numerical simulation of viscoelastic fluid flows. This paper presents an improved lattice Boltzmann metho…
Lattice Boltzmann simulation reveals supercritical bifurcation in flow mode transitions of power-law fluids in the four-roll mill
Yuan Yu, Xiao Jiang, Qingqing Gu +3
The four-roll mill has been traditionally viewed as a device generating simple extensional flow with a central stagnation point. Our systematic investigation using a two-relaxation…