Page 98 - 《摩擦学学报》2020年第5期

第 5 期 吴可欣, 等: 阻旋栅对梳齿密封动静特性影响研究 653

16 8
n=0, λ=0.36 4 No brake
n=90, λ=0.36
Circumferential velocity/(m/s) 10 8 6 4 n=0, λ=0.81 Cross-coupled stiffness/(10 3 N/m) −4 0
14
s=0.25
n=0, λ=0.51
s=0.20
n=90, λ=0.51
12
s=0.15
n=90, λ=0.81

0 2 −8
30 31 32 33 34 0 50 100 150 200 250 300
Position/mm Whirling frequency/Hz
Fig. 12 Circumferential velocity distribution for Fig. 15 Cross-coupled stiffness vs whirling frequency
different preswirl ratios for various swirl brake clearances
图 12 不同预旋比下密封腔周向速度分布 图 15 不同阻旋栅间隙下交叉刚度k随涡动频率变化

8.815 n=60, l=2.25, s=0.20 8.845 50 No brake
Pressure with swirl brakes/10 5 Pa 8.805 n=30, l=3.25, s=0.20 n=60, l=3.25, s=0.25 8.840 Pressure without swirl brakes/10 5 Pa Effective damping/(N·s/m) 30
n=60, l=4.25, s=0.20
s=0.25
40
n=60, l=3.25, s=0.15
8.810
s=0.20
s=0.15
20
8.835
8.800
10
8.795
No brake
8.790 n=90, l=3.25, s=0.20 8.830 −10 0
0 100 200 300 400 0 50 100 150 200 250 300
Degree/(°) Whirling frequency/Hz
Fig. 13 Pressure distribution with different Fig. 16 Effective damping vs whirling frequency for
structures of swirl brakes various swirl brake clearances
图 13 不同阻旋栅结构下密封周向压力分布 图 16 不同阻旋栅间隙下有效阻尼C eff 随涡动频率变化

27 No brake 27 No brake
s=0.25 24 l=2.25
l=3.25
Direct damping/(N·s/m) 21 Direct damping/(N·s/m) 21
s=0.20
l=4.25
24
s=0.15
18
18
15 15
0 50 100 150 200 250 300 0 50 100 150 200 250 300
Whirling frequency/Hz Whirling frequency/Hz
Fig. 14 Direct damping vs whirling frequency for Fig. 17 Direct damping vs whirling frequency for
various swirl brake clearances various swirl brake lengths
图 14 不同阻旋栅间隙下直接阻尼C随涡动频率变化 图 17 不同阻旋栅长度下直接阻尼C随涡动频率变化

2.2.2 阻旋栅长度 同阻旋栅长度下密封直接阻尼和有效阻尼均提高，交

图17~19分别给出了不同阻旋栅长度(无阻旋栅、 叉刚度降低；②随阻旋栅长度增加对密封在低频下有
l=2.25 mm、l=3.25 mm、l=4.25 mm)下密封直接阻尼、 效阻尼影响较大，当l=3.25 mm、l=4.25 mm时，密封有
交叉刚度及有效阻尼随涡动频率变化(P =1 MPa、 效阻尼比l=2.25 mm时有明显提升，而在高频下，阻旋
in
P =0.3 MPa、N=5000 r/min、 λ=0.36). 可以看出：①不 栅长度对密封动力特性影响较小.
out