Two-Dimensional CFD Modeling of Hysteresis Behavior of MR Dampers

Table 1

Auxiliary variables defined in COMSOL for implementation convenience.

Physical meaning	Name	Expression in COMSOL
Shear rate	D11	2 ∗ ur
	D13	uz + wr
	D22	2 ∗ u/r
	D33	2 ∗ wz
Magnitude of shear rate	sr	Sqrt (0.5 ∗ 4 ∗ (u/r)^2 + 2∗ (uz + wr)^2 + 4 ∗ (wz)^2 + eps)
Total stress	Sigma11	etan ∗ D11 + tau11-p
	Sigma13	etan ∗ D13 + tau13
	Sigma22	etan ∗ D22 + tau22-p
	Sigma33	etan ∗ D33 + tau33-p
Divergence of velocity	vdiv	u/r + ur + wz

Note. According to the expression conventions of COMSOL, the spatial derivative of a variable, for example, , is represented by u/r. The postyield viscosity implemented in COMSOL, etan, is 1.5 Pa·s.