mi14061267.pdf - 第9页

Micromachines 2023 , 14 , 1267 9 of 17 Changing the viscosity of the oil will change the viscous resistance of the liquid, and a change in the viscous resistance will lead to a change in kinetic energy loss during the mo…

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Micromachines 2023, 14, 1267 8 of 17
Signal frequency also has an influence on the injection performance. When the fre-
quency of the applied signal is just under the frequency of the vibrator
0
s operating mode,
the amplitude of the vibrator will increase, and the injection performance will be affected
by changing the vibration amplitude of the vibrator. Figures 11–13 show the influence
of the change in signal frequency on the injection performance. It can be seen from the
comprehensive analysis of Figures 11–13 that the change in signal frequency has little
influence on the injection performance of the droplet within the range of 7940–8240 Hz.
Micromachines 2023, 14, x FOR PEER REVIEW 12 of 28
The signal frequency is 8040Hz
The signal frequency is 8090Hz
The signal frequency is 8140Hz The signal frequency is 8190Hz The signal frequency is 8240Hz
The signal frequency is 7940Hz
The signal frequency is 7990Hz
0.682T0.698T 0.698T
0.69T
0.703T
0.7068T
0.686T
1
9.000× 10
-1
0
8.000× 10
-1
7.000× 10
-1
6.000× 10
-1
5.000× 10
-1
4.000× 10
-1
3.000× 10
-1
2.000× 10
-1
1.000× 10
-1
1
9.00 0×10
-1
0
8.000× 10
-1
7.00 0×10
-1
6.00 0×10
-1
5.00 0×10
-1
4.000× 10
-1
3.000× 10
-1
2.000× 10
-1
1.00 0×10
-1
1
9.000× 10
-1
0
8.000× 10
-1
7.000× 10
-1
6.000× 10
-1
5.000× 10
-1
4.000× 10
-1
3.000× 10
-1
2.000× 10
-1
1.000× 10
-1
1
9.00 0×10
-1
0
8.000× 10
-1
7.00 0×10
-1
6.00 0×10
-1
5.00 0×10
-1
4.000× 10
-1
3.000× 10
-1
2.000× 10
-1
1.00 0×10
-1
1
9.000× 10
-1
0
8.000× 10
-1
7.000× 10
-1
6.000× 10
-1
5.000× 10
-1
4.000× 10
-1
3.000×10
-1
2.000× 10
-1
1.000× 10
-1
1
9.000× 10
-1
0
8.000×10
-1
7.000× 10
-1
6.000× 10
-1
5.000× 10
-1
4.000×10
-1
3.000× 10
-1
2.000×10
-1
1.000× 10
-1
1
9.000× 10
-1
0
8.000× 10
-1
7.000× 10
-1
6.000× 10
-1
5.000× 10
-1
4.000× 10
-1
3.000×10
-1
2.000× 10
-1
1.000× 10
-1
Figure 11. The change in droplet ejection state caused by the change in signal frequency.
Figure 11. The change in droplet ejection state caused by the change in signal frequency.
Micromachines 2023, 14, x FOR PEER REVIEW 13 of 28
The signal frequency is 8040Hz
The signal frequency is 8090Hz
The signal frequency is 8140Hz
The signal frequency is 8190Hz
The signal frequency is 8240Hz
The signal frequency is 7940Hz
The signal frequency is 7990Hz
0.682T
0.698T
0.698T 0.69T
0.703T
0.7068T
0.686T
0
1.61 3
1.075
5.377
4.839
4.301
3.76 4
3.226
2.68 8
2.15 1
5.37 7×10
-1
0
1.613
1.07 6
5.37 8
4.84 0
4.30 2
3.764
3.22 7
2.689
2.151
5.378×10
-1
0
1.61 8
1.079
5.39 3
4.85 4
4.315
3.77 5
3.236
2.697
2.15 7
5.39 3×10
-1
0
1.664
1.10 9
5.54 6
4.99 2
4.43 7
3.882
3.32 8
2.773
2.21 8
5.546×10
-1
0
1.63 5
1.09 0
5.449
4.904
4.35 9
3.81 4
3.26 9
2.72 5
2.180
5.44 9×10
-1
0
1.63 4
1.089
5.44 5
4.90 1
4.356
3.81 2
3.26 7
2.723
2.17 8
5.44 5×10
-1
0
1.62 9
1.08 6
5.428
4.886
4.34 3
3.80 0
3.257
2.71 4
2.171
5.42 8×10
-1
Figure 12. The change in droplet outlet velocity caused by the change in signal frequency.
Figure 12. The change in droplet outlet velocity caused by the change in signal frequency.
Micromachines 2023, 14, x FOR PEER REVIEW 14 of 28
7940Hz
7990Hz
8040Hz
8090Hz
8140Hz
8190Hz
8240Hz
Droplet volume [ L ]
0 0.00005 0.0001 0.00015 0.0002 0.00025 0.0003
Time [ s ]
0
8
410
−
×
8
310
−
×
8
210
−
×
8
110
−
×
8
110
−
−×
8
210
−
−×
Figure 13. The change in the volume of droplets ejected caused by the change in signal frequency.
Changing the viscosity of the oil will change the viscous resistance of the liquid, and
a change in the viscous resistance will lead to a change in kinetic energy loss during the
movement of the droplets. The influence of the change in the oil viscosity on the injection
performance is shown in Figures 14–16. Figure 14 reflects the influence of the change in
oil viscosity on the ejection state of the droplets. It can be seen that with the increase in oil
viscosity, the droplets are more difficult to be ejected, and the time of ejection is later.
Figure 15 shows the influence of the change in oil viscosity on the outlet velocity of the
droplet. With the increase in oil viscosity, the larger the kinetic energy loss of the droplet,
the lower the outlet velocity. Figure 16 reflects the influence of the change in oil viscosity
on the volume of droplets ejected. The analysis shows that when the viscosity is less than
100 Pa.s, the higher the oil viscosity, the smaller the volume of droplets ejected, and the
higher the control accuracy but the lower the efficiency. When the oil viscosity is between
100 and 200 Pa.s, the oil viscosity has lile influence on the volume of droplets. The com-
prehensive analysis shows that when the oil viscosity is greater than 100 Pa.s, the increase
in the oil viscosity has a weak effect on the improvement in the control accuracy, but it
will reduce the droplet outlet velocity and increase the difficulty of droplet injection,
which will lead to the unsatisfactory injection performance of the device.
Figure 13. The change in the volume of droplets ejected caused by the change in signal frequency.
Micromachines 2023, 14, 1267 9 of 17
Changing the viscosity of the oil will change the viscous resistance of the liquid, and
a change in the viscous resistance will lead to a change in kinetic energy loss during the
movement of the droplets. The influence of the change in the oil viscosity on the injection
performance is shown in Figures 14–16. Figure 14 reflects the influence of the change
in oil viscosity on the ejection state of the droplets. It can be seen that with the increase
in oil viscosity, the droplets are more difficult to be ejected, and the time of ejection is
later. Figure 15 shows the influence of the change in oil viscosity on the outlet velocity
of the droplet. With the increase in oil viscosity, the larger the kinetic energy loss of the
droplet, the lower the outlet velocity. Figure 16 reflects the influence of the change in oil
viscosity on the volume of droplets ejected. The analysis shows that when the viscosity is
less than 100 Pa.s, the higher the oil viscosity, the smaller the volume of droplets ejected,
and the higher the control accuracy but the lower the efficiency. When the oil viscosity is
between 100 and 200 Pa.s, the oil viscosity has little influence on the volume of droplets.
The comprehensive analysis shows that when the oil viscosity is greater than 100 Pa.s, the
increase in the oil viscosity has a weak effect on the improvement in the control accuracy,
but it will reduce the droplet outlet velocity and increase the difficulty of droplet injection,
which will lead to the unsatisfactory injection performance of the device.
Micromachines 2023, 14, x FOR PEER REVIEW 15 of 28
The oil viscosity is 125cs
The oil viscosity is 150cs
The oil viscosity is 175cs
The oil viscosity is 200cs
The oil viscosity is 10cs
The oil viscosity is 50cs
The oil viscosity is 100cs
0.62T 0.628T 0.637T
0.641T
0.653T
0.6572T
0.682T
1
9.00 0×10
-1
0
8.000×10
-1
7.00 0×10
-1
6.00 0×10
-1
5.00 0×10
-1
4.000×10
-1
3.00 0×10
-1
2.000×10
-1
1.00 0×10
-1
1
9.00 0×10
-1
0
8.00 0×10
-1
7.00 0×10
-1
6.00 0×10
-1
5.00 0×10
-1
4.00 0×10
-1
3.00 0×10
-1
2.00 0×10
-1
1.00 0×10
-1
1
9.00 0×10
-1
0
8.000×10
-1
7.00 0×10
-1
6.00 0×10
-1
5.00 0×10
-1
4.000×10
-1
3.00 0×10
-1
2.000×10
-1
1.00 0×10
-1
1
9.00 0×10
-1
0
8.00 0×10
-1
7.00 0×10
-1
6.00 0×10
-1
5.00 0×10
-1
4.00 0×10
-1
3.00 0×10
-1
2.00 0×10
-1
1.00 0×10
-1
1
9.00 0×10
-1
0
8.00 0×10
-1
7.00 0×10
-1
6.00 0×10
-1
5.00 0×10
-1
4.00 0×10
-1
3.00 0×10
-1
2.00 0×10
-1
1.00 0×10
-1
1
9.00 0×10
-1
0
8.00 0×10
-1
7.00 0×10
-1
6.00 0×10
-1
5.00 0×10
-1
4.00 0×10
-1
3.000×10
-1
2.00 0×10
-1
1.00 0×10
-1
1
9.00 0×10
-1
0
8.00 0×10
-1
7.00 0×10
-1
6.00 0×10
-1
5.00 0×10
-1
4.00 0×10
-1
3.000×10
-1
2.00 0×10
-1
1.00 0×10
-1
Figure 14. The change in droplet ejection state caused by the change in oil viscosity.
Figure 14. The change in droplet ejection state caused by the change in oil viscosity.
Micromachines 2023, 14, x FOR PEER REVIEW 16 of 28
The oil viscosity is 125cs
The oil viscosity is 150cs The oil viscosity is 175cs
The oil viscosity is 200cs
The oil viscosity is 10cs
The oil viscosity is 50cs
The oil viscosity is 100cs
0.62T 0.628T 0.637T 0.641T
0.653T
0.6572T
0.682T
9.28 3
0
8.252
7.22 0
6.18 9
5.15 7
4.126
3.094
2.063
1.031
1.031×10
1
8.770
0
7.795
6.821
5.846
4.872
3.898
2.923
1.949
9.744
9.744× 10
-1
7.676
0
6.823
5.970
5.117
4.264
3.411
2.55 9
1.706
8.529
8.529×10
-1
7.161
0
6.36 6
5.570
4.774
3.978
3.18 3
2.387
1.59 1
7.957
7.957× 10
-1
6.494
0
5.77 2
5.051
4.329
3.608
2.88 6
2.165
1.44 3
7.215
7.215×10
-1
5.825
0
5.17 7
4.530
3.883
3.236
2.58 9
1.942
1.29 4
6.472
6.472×10
-1
4.992
0
4.437
3.882
3.328
2.773
2.218
1.664
1.109
5.546
5.546×10
-1
Figure 15. The change in droplet outlet velocity caused by the change in oil viscosity.
Figure 15. The change in droplet outlet velocity caused by the change in oil viscosity.
Micromachines 2023, 14, 1267 10 of 17
Micromachines 2023, 14, x FOR PEER REVIEW 17 of 28
200CS
125CS
150CS
175CS
10CS
100CS
50CS
Droplet volume [ L ]
0 0.00005 0.0001 0.00015 0.0002 0.00025 0.0003
Time [ s ]
0
8
410
−
×
8
310
−
×
8
210
−
×
8
110
−
×
8
110
−
−×
8
210
−
−×
Figure 16. The change in the volume of droplets ejected caused by the change in oil viscosity.
The influence of the change in nozzle diameter on the injection performance is shown
in Figures 17–19. Figure 17 shows the influence of the change in nozzle diameter on the
ejection state of the droplet. With the increase in nozzle diameter, the stability of the drop-
let slightly decreases, and the tail begins to jier. The larger the diameter of the nozzle, the
greater the difficulty of the droplet ejection and the later the droplet ejection time. Figure
18 shows the influence of the nozzle diameter change on the droplet outlet velocity. With
the increase in the nozzle diameter, the droplet outlet velocity gradually decreases. The
nozzle diameter can be appropriately reduced if the initial kinetic energy of the droplet is
to be increased. Figure 19 shows the influence of the nozzle diameter change on the vol-
ume of droplets. It can be seen that with the increase in the nozzle diameter, the volume
of droplets ejected by the piezoelectric micro-jet device gradually increases. If the size of
droplets ejected is to be increased to improve the injection efficiency, the nozzle diameter
can be increased.
Figure 16. The change in the volume of droplets ejected caused by the change in oil viscosity.
The influence of the change in nozzle diameter on the injection performance is shown
in Figures 17–19. Figure 17 shows the influence of the change in nozzle diameter on the
ejection state of the droplet. With the increase in nozzle diameter, the stability of the droplet
slightly decreases, and the tail begins to jitter. The larger the diameter of the nozzle, the
greater the difficulty of the droplet ejection and the later the droplet ejection time. Figure 18
shows the influence of the nozzle diameter change on the droplet outlet velocity. With
the increase in the nozzle diameter, the droplet outlet velocity gradually decreases. The
nozzle diameter can be appropriately reduced if the initial kinetic energy of the droplet
is to be increased. Figure 19 shows the influence of the nozzle diameter change on the
volume of droplets. It can be seen that with the increase in the nozzle diameter, the volume
of droplets ejected by the piezoelectric micro-jet device gradually increases. If the size of
droplets ejected is to be increased to improve the injection efficiency, the nozzle diameter
can be increased.
Micromachines 2023, 14, x FOR PEER REVIEW 18 of 28
The nozzle
diameter is 0.2mm
The nozzle diameter
is 0.25mm
The nozzle
diameter is 0.3mm
The nozzle diameter
is 0.35mm
The nozzle
diameter is 0.4mm
0.454T 0.467T 0.537T
0.6572T 0.682T
1
9.00 0×10
-1
0
8.00 0×10
-1
7.00 0×10
-1
6.00 0×10
-1
5.00 0×10
-1
4.00 0×10
-1
3.00 0×10
-1
2.00 0×10
-1
1.00 0×10
-1
1
9.00 0×10
-1
0
8.00 0×10
-1
7.00 0×10
-1
6.00 0×10
-1
5.00 0×10
-1
4.00 0×10
-1
3.00 0×10
-1
2.00 0×10
-1
1.00 0×10
-1
1
9.00 0×10
-1
0
8.00 0×10
-1
7.00 0×10
-1
6.00 0×10
-1
5.00 0×10
-1
4.00 0×10
-1
3.00 0×10
-1
2.00 0×10
-1
1.00 0×10
-1
1
9.00 0×10
-1
0
8.00 0×10
-1
7.00 0×10
-1
6.00 0×10
-1
5.00 0×10
-1
4.00 0×10
-1
3.00 0×10
-1
2.00 0×10
-1
1.00 0×10
-1
1
9.00 0×10
-1
0
8.00 0×10
-1
7.00 0×10
-1
6.00 0×10
-1
5.00 0×10
-1
4.00 0×10
-1
3.00 0×10
-1
2.00 0×10
-1
1.00 0×10
-1
Figure 17. The change in droplet ejection state caused by the change in nozzle diameter.
Figure 17. The change in droplet ejection state caused by the change in nozzle diameter.