Study on Angular Free Vibration Stability and Parameters Influence of Dry Gas Seal Based on the Characteristic Equation

Table 1

Characteristic parameter values of DGS system under critical instability state according to Hurwitz stability criterion.

Influencing factors	Unit	Equation (27a)	Equation (27b)	Equation (27c)	Equation (27d)	Intersection of values
cxx + csx	N·m·s·rad^−1	>0	Permanent establishment	>22.2474	<−6.9260 or >29.1703	>29.1703
kxx + ksx	N·m·rad^−1	No influence	>−5.5563 × 10^6	>2.3881 × 10^4	>2.5190 × 10^4	>2.5190 × 10^4
cyx	N·m·s·rad^−1	No influence	Permanent establishment	<249.1186	<247.2842	<247.2842
kyx	N·m·rad^−1	No influence	No influence	>−8.8036 × 10^5	>−6.7149 × 10^5 and <2.8280 × 10^6	>−6.7149 × 10^5 and <2.8280 × 10^6
I	kg·m^2	No influence	Permanent establishment	No influence	<0.3021	<0.3021