© Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and...
-
Upload
wilfred-ball -
Category
Documents
-
view
235 -
download
7
Transcript of © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and...
![Page 1: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/1.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
1
Frank KameierProfessor for Fluid Mechanics and Acoustics
Unsteady Aerodynamics in Turbomachines
• Rotating Stall and Surge
• Rotating Instabilities and Blade Vibrations (Flow-induced Vibrations)
• The „Demonstrator“ of FH Düsseldorf
![Page 2: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/2.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
2
Operating Map (Compressor)– non dimensional
0
0,1
0,2
0,3
0,4
0,5
0,6
0,7
-0,05 0 0,05 0,1 0,15 0,2 0,25
j
y
Rotating Instabilities
Rotating Stall
Surge
Design Conditions
![Page 3: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/3.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
3
Flow Separation in a Turbomachine(Compressor)
NGV Dresden
y
j
„Abrupt Stall“
![Page 4: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/4.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
4
Surge Conditions
High Pressure Compressor A pressure wave with an amplitude of several bar propagates from rear to front stages.
Damage of the rotor blades after app. 1000 surge cycles.
y
j
![Page 5: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/5.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
5
Instrumentation – Wall Pressure Transducers - Kulite XT190
4 mm
Piezo-resisitive
(DC up to 30 kHz)
![Page 6: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/6.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
6
Surge Test Nhrt=60%
Expansion
Wall pressureTemperature
![Page 7: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/7.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
7
Wall Pressure Fluctuations at Surge Conditions
![Page 8: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/8.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
8
Wall Pressure Fluctuations at Bang-Test-Conditions
s 45.12 45.122 45.124 45.126 45.128 45.13 45.132 45.134 45.136 45.138
kPa
-1
-0.5
0
0.5
Pressure
B0215A1 (RIG302_2/D2on190896t01 [B])
B0215B1 (RIG302_2/D2on190896t01 [B])
B0215C1 (RIG302_2/D2on190896t01 [B])
RIG 302_2 Bang Test
Kameier/Holste ET-24pak2 21.10.96 10:44
Event: 19.08.96 19:07h
2 ms
axial shot = plane wave
![Page 9: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/9.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
9
Wall Pressure Fluctuations at Bang-Test-Conditions
lateral shot = non plane wave
![Page 10: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/10.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
10
Surge Analysis in a 10-Stage Compressor
-1
0
1
2
3
4
5
6
7
8
9
B0206B1 B0215A1 B0223A1 B0231A1 B0239A1 B0247A1 B0255A1 B0263B1 B0271B1 B0279A1
Pressure transducers along 10-stage compressor
Ord
er
of
reac
tio
n
NHrt 100%
Shock amplitude sign
![Page 11: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/11.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
11
Rotating Instabilities – a Periodic Vortex Shedding?
Flow around a cylinderR.Feynman, Lectures on Physics, 1974
![Page 12: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/12.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
12
Kármán Vortex Separation Causes Mechanical Damage
Ferrybridge, England 1965
Ref.: Sahlmen, Niemann http://www.aib.ruhr-uni-bochum.de/
![Page 13: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/13.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
13
Kármán Vortex Separation Causes “Stall Flutter”
s
m19c
![Page 14: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/14.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
14
Rotating Instabilities – a Wall Shear Stress Fluctuation?
Schlichting, Boundary Layer Theory
![Page 15: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/15.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
15
Rotating Instabilities and Blade Vibrations
Wall pressure fluctuations- fixed frame of reference -
Blade vibrations- rotating frame of reference -
BAUMGARTNER, KAMEIER, HOURMOUZIADIS, ISABE Conference, Melbourne, 1995
Restricted speed range
![Page 16: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/16.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
16
Rotating Instabilities and Blade Vibrations
Wall pressure fluctuations- fixed frame of reference -
Blade vibrations- rotating frame of reference -
![Page 17: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/17.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
17
Tip Clearance Effect of an Axial Flow Machine
Hysterese-sprung
![Page 18: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/18.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
18
10 Stage High-Speed Compressor N =13200 rpm (83 %)
110
130
150
170
190
0 2000 4000 6000 8000 10000 12000 14000 16000
f [ Hz ]
Lp [dB]
1.BPF
2.BPF
RI
1.BPF + RI
1.BPF - RI
DLR Low-Speed Compressor N =1400 rpm (Point of maximum efficiency)
50
70
90
110
130
150
0 200 400 600 800 1000 1200
f [ Hz ]
Lp [dB]
1.BPF
2.BPF
RI
1.BPF + RI
1.BPF - RI
High pressure compressor13200 U/min
Low speed fan1400 U/min
![Page 19: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/19.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
19
High Pressure Compressor – Speed Variation
f[Hz]
t[s]
p[Pa]
![Page 20: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/20.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
20
Acoustic Resonances – Aero Engine Occurence
Speed of sound is the speed of propagation• Helmholtz-Resonator
• Standing waves and orifice resonance
• Self-induced acoustical resonances - „Parker Modes“ – Orgen-pipe resonances
Vd
L
daf
4
4
01 4
1f
L
af 02 4
3f
L
af bzw.
Sharp peak!
[Hz]
![Page 21: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/21.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
21
“Acoustic Resonance” Downstream of a Flat Plate in Flow
Quelle: Parker, Aeroacoustics, International Journal of Fluid Dynamics, 1997http://www-vhost.monash.edu.au/elecpress/ijfd/1997_vol1/paper1/Parker.Flow.html
![Page 22: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/22.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
22
Wall Pressure Fluctuations Upstream Rotor 1(HPC)
y
j
Operating conditions on secondary characteristics
Rotating stall
![Page 23: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/23.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
23
Wall Pressure Fluctuations Upstream Rotor 1(HPC)
y
j
Operating conditionsclose to design
Transonic flow in the blade tip region
![Page 24: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/24.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
24
Rotor 1 Redesign - Wall Pressure Fluctuations
y
j
Operating conditions close to surge margin
Redesign
![Page 25: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/25.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
25
Circumferential Distribution of Rotating Instabilities
Wall Pressure Fluctuations
Power spectrum
Coherence
Phase spectrum
![Page 26: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/26.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
26
Rotating Stall as a Special Case of Rotating Instabilities
jj tcosAt,p QQQ
tFQ
FQ jj
jj tcosAt,p F
QQFF
FQ
QF
RF
FQ
F RQ
R
0Q „Rotating Stall“
![Page 27: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/27.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
27
Rotating Stall in a Compressor Blade Row
RSR rp+
p-
U = r
.
![Page 28: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/28.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
28
Negative Frequencies and Rotating Stall
RRS
RRS F
RSFRS
RF
RF
![Page 29: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/29.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
29
Rotating Stall – Part Span Stall
Turbotech II - Teilvorhaben Nr. 1.244
Fixed frame
Rotor frame
![Page 30: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/30.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
30
Historical Review: „Instabilities“ in the Atmosphere of the Earth
(Chen, Haupt, Rautenberg, Uni Hannover, 1987)
A circumferential propagating Kármán vortex street: Rossby-wave
![Page 31: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/31.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
31
Rotating Stall in a Centrifugal Impeller
Quelle: Bohl, Strömungsmaschinen, 1994
![Page 32: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/32.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
32
Sound Generation by Rotating Stall in Centrifugal Turbomachines
Inlet Duct Impeller Blade
Rotating Instability
(Mongeau, Pennsylvania State University, 1991)
![Page 33: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/33.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
33
Rotating Instability Waves in a Ducted
Axial Fan
(Krane, Bent, Quinlan, AT&T Bell Laboratories, 1995)
![Page 34: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/34.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
34
Rotating Instabilities in a Steam Turbine (Low Pressure Stage)
Power spectrum Coherence along circumference
vgl.: Truckenmüller, Gerschütz, Stetter, Hosenfeld, Uni Stuttgart, ImechE, London 99
![Page 35: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/35.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
35
Rotating Instabilities - Periodical Unsteady Flow Field Within aRotor Blade Row of an Axial Compressor (TU Dresden)
vgl.: Mailach, Vogler, Lehmann, TU Dresden, ASME Montreal 2007
![Page 36: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/36.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
36
Rotating Stall Rotating Instabilities
RS
D
separated flow randomised behaviour turbulent frequencies are not related to the number of rotor blades
separated flow discrete behaviour periodical frequencies are related to the number of rotor blades
PitchBladeZ
DD
RI
FR
FRS 6.0...4.0 F
RFRI Z6.0...4.0
![Page 37: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/37.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
37
Correlation of Vibration and Pressure Fluctuations – Measurements on the Demonstrator of FH Düsseldorf (Co-op Rolls-Royce Germany)
![Page 38: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/38.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
38
Unsteady Instrumentation – Fixed Frame of Reference
Transducers
- 16 ¼‘‘ MicrofonesMicrotech MK301.
- Accelerometer B&K 4371
- Polytec Laservibrometer
Transducer positions
- 84 circumferential positions, = 4.285°.
- 6 positions in the rotor wake region, = 60°.
![Page 39: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/39.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
39
Unsteady Instrumentation – Rotating Frame of Reference
Blades with transducers
Transducer
- 4 Pressure transducersKulite LQ-47 und LQ125
- Strain Gages HBM
- Rotating 8-chanel amplifier unitDLR Berlin,4 x Kulites, 4x Strain Gage
- 10 – chanel slip ring unit
![Page 40: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/40.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
40
Unsteady Instrumentation – Rotating Frame of Reference
Strain Gage
Pressure Transducers LQ-47, LQ125
Transducer
- 4 Pressure transducersKulite LQ-47 und LQ125
- Strain Gages HBM
- Rotating 8-chanel amplifier unitDLR Berlin,4 x Kulites, 4x Strain Gage
- 10 – chanel slip ring unit
![Page 41: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/41.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
41
Unsteady Instrumentation – Rotating Frame of Reference
8-Channel amplifier unit (rotating)
10-Channel Slip-ring
Transducer
- 4 Pressure transducersKulite LQ-47 und LQ125
- Strain Gages HBM
- Rotating 8-chanel amplifier unitDLR Berlin,4 x Kulites, 4x Strain Gage
- 10 – chanel slip ring unit
![Page 42: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/42.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
42
Continuous Throttle Procedure n=1000min-1 – Wall Pressure
Excitation of Modes = 20 ... 9
0.060.100.15 0.05j
0.18 0.17 0.14 0.13 0.12 0.11 0.090.16 0.060.100.15 0.05j
0.18 0.17 0.14 0.13 0.12 0.11 0.090.16
Fixed Frame of Reference, = 60°, 1000min-1, f = 1Hz Rotating Frame of Reference, = 60°, 1000min-1, f = 1Hz
![Page 43: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/43.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
43
Continuous Throttle Procedure n=1000min-1 - Rotating Frame of Reference (Strain Gauge) -
Soft Blade feigen ~ 69Hz
0.060.100.15 0.05j
0.17 0.16 0.14 0.13 0.12 0.11 0.09 0.060.100.15 0.05j
0.17 0.16 0.14 0.13 0.12 0.11 0.09
Stiff Blade feigen ~ 97Hz
Excitation of Modes = 20 ... 9
![Page 44: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/44.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
44
Continuous Throttle Procedure n=1000min-1 - Increased Blade Loading - Fixed Frame of Reference –
Excitation of Modes = 5, 6, 6.5 und 7
0.050.17
j
0.20 0.19 0.16 0.15 0.10
Rotating Stall
![Page 45: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/45.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
45
Statistical Analysis of Rotating Instability and Rotating Stall
Rotating Stall
2
2
2
2
1)(
x
exf
Gauß Distribution
Rayleigh Distribution
2
2
22
c
x
ec
xxf
RI-Frequenzen
Umgebungsrauschen
Histogram of Rotating Stall amplitudes
6 8 10 12 14 16 18 200
0.02
0.04
0.06
0.08
0.1
0.12
0.14Wahrs cheinlichkeits funktion gewichtet der RS -Frequenz (4Hz), 800 1/min, P hi = 0,17, M19 R 355, 1500 S pektren
[Pa]
f(x)
23Anz.Klas s en =
0.519Klas s enbreite =
12.524 =
12.6482 =
1.772 =
3.1392 =
9.992c =
0.042S chiefe =
-0.074Wölbung =
Gaus s -Vert. Rayleigh-Vert
Histogram of Rotating Instability amplitudes
0 5 10 15 20 25 30 350
0.02
0.04
0.06
0.08
0.1
0.12Wahrscheinlichkeits funktion gewichtet e iner RI-Frequenz (72Hz), 800 1/min, P hi = 0,17, M19 R 355, 1500 Spektren
[Pa]
f(x)
23Anz.Klas s en =
1.422Klass enbreite =
11.580 =
12.9212 =
5.733 =
32.8642 =
9.240c =
0.395Schiefe =
-0.303Wölbung =
Gaus s -Vert. Rayleigh-Vert
![Page 46: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/46.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
46
Rotating Stall and Rotating Instabilities
„primary“ - Characteristics
Stall region
Rotating Instabilities(Schematical Sketch)
Rotating Stall(Schematical Sketch)
![Page 47: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/47.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
47
Flow Field with RIFlow visualization -
Single stage compressor along throttling procedure
Tip Clearance Flow
Quelle: Kameier 1994.
Small Gap Large Gap
j
c
c
Rotorblade
Starting Hypothesis
Small Gap Large Gap
Small Gap Large Gap
No secondary flow region, no separated boundary layer
Secondary flow region
Point of separation
![Page 48: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/48.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
48
Low Flow Rate
Separated Flow RegionSeparated Flow Region
High Flow Rate
![Page 49: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/49.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
49
High Flow Rate Low Flow Rate
Separated Flow RegionSeparated Flow Region
![Page 50: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/50.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
50
Tip Clearance s*= 0%, Low Flow Rate
Tip Clearance VariationTip Clearance s*= 2%,
Low Flow Rate
![Page 51: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/51.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
51
Summary
Stufe 1
Stufe 1
Stufe 1
.redm
RS
RS+RI
RI
![Page 52: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/52.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
52
Rotating Instabilities
Rotating instabilities occur in radial and axial flow machines.
RI is explained as a pulsating separated flow region which is rotating relative to the rotor in rotor direction (slip condition).
It is impossible to predict a rotating instability.
A numerical model is not known yet.
![Page 53: © Frank Kameier - Fluid Mechanics and Acoustics 1 Frank Kameier Professor for Fluid Mechanics and Acoustics Unsteady Aerodynamics in Turbomachines Rotating.](https://reader038.fdocuments.us/reader038/viewer/2022102713/56649f345503460f94c513a1/html5/thumbnails/53.jpg)
© Frank Kameier - Fluid Mechanics and Acoustics
53
Fluid Mechanics and Acoustics at FH DüsseldorfInstitute of Sound and Vibration Engineering (in the course of formation)
• CAE of centrifugal flow machines (funded by BMBF)
• Low noise design (Outflow Valve Boeing 787)
• Flow induced vibrations (funded by BMW AG)
• Steady state CFD for localising unsteady mechanisms (funded by BMW AG)
• Combustor resonances (funded by Weishaupt GmbH)
• Noise reduction of roots compressors (funded by Lufttechnik KG)
• Optimisation of vacuum cleaner (Aeroacoustics) (funded by Miele)
Current Research and Development