Page Content
Linear High Speed Compressor Stator Cascade for Active Flow Control Investigations
- Compressor Cascade
[1]
- © TUB F1
Aircraft manufacturers and airlines demand for
highly efficient engines to address the more and more stringent
requirements in terms of economy and environmental compatibility.
This target requires light and compact propulsion systems,
leading to the necessity to reduce the weight of the single
components. Within the compressor module, the number of the required
stages can be minimized by a higher stage pressure ratio at constant
total pressure ratio. This can be done by a stronger turning of the
flow within the passage of a supercritical compressor cascade.
Nevertheless, separation needs to be avoided, one approach being
active flow control.
At the Technical University of Berlin
projects investigating active flow control concepts have been
executed within the Collaborative Research Center 557, Control of
turbulent shear flows.
At the department of Aeronautics
and Astronautics of the Technical University of Berlin, a linear
stator cascade test facility for active flow control investigations
was developed and tested at high speed flow conditions. The
compressor blades were designed as critically loaded controled
diffusion airfoils (CDA) for an upstream Mach number of M
= 0.75 and a Reynolds number of Re = 1.1 • 10^6 based on axial
chord.
As a basis for the development of a closed-loop
active flow control method, a detailed investigation of the flow
field without actuation is necessary. Five-hole probes have been used
to determine the pressure field and the flow direction of the wake
behind the compressor blade. Furthermore an analysis of the baseline
cascade flow by oil flow pattern reveals complex three-dimensional
secondary flow phenomena. On the suction side of the blades close to
the leading edge, a laminar separation bubble is observed. Where blade
and side walls meet, corner stall is developing. Caused by the blade
aspect ratio of 0.8, the passage flow is strongly influenced by
these vortices. Uniform main passage flow is thus constricted to the
midspan region, leading to a reduction of the passage efficiency. The
aim is to investigate how the secondary flow phenomena
can be supressed by active flow control methods to receive a higher
stage pressure ratio or lower total pressure losses respectively and
where limits of these methods can be found.
For this
purpose, actuators for steady and pulsed blowing through a side wall
blowing nozzle were developed. Active flow control
investigations have been carried out in the cascade test rig for
different incidences and inflow Mach numbers and variations of the
jets mass flow rate, the velocity ratio and the actuation frequency
to investigate the influence of the injected air on the cascade
flow.
Person of contact: Dr.-Ing. Christine
Tiedemann
To top
References
Determination of the
pressure distribution and fluctuations of the transonic flow in a
highly loaded compressor
cascade
K.
Hummel, C. Tiedemann, D. Peitsch
(TU Berlin)
Deutscher
Luft- und Raumfahrtkongress 2013,
Stuttgart, Germany, September
10-12 2013, DLRK 2013-301482
Identification of surrogate control variables for a
robust active flow controller of an experimental high speed stator
cascade
S. Steinberg, C.
Tiedemann, R. King, D. Peitsch
(TU Berlin)
ASME Turbo
Expo 2013,
San Antonio, USA, June 3-7 2013, GT2013-94179
Identifikation einer Regelgröße zur aktiven
Strömungskontrolle an einer linearen Verdichterkaskade im
kompressiblen Machzahlbereich
C. Tiedemann,
S. Steinberg, D. Peitsch, R. King
(TU Berlin)
Deutscher Luft- und Raumfahrtkongress 2012,
Berlin, Germany,
September 10-12 2012, DLRK 2012-281267
A
new linear high speed compressor stator cascade for active flow
control investigations
C. Tiedemann, A.
Heinrich, D. Peitsch
(TU Berlin)
6th AIAA Flow Control
Conference,
New Orleans, USA, June 25-28 2012, AIAA-2012-3251
To top
g/Verdichterkaskade.jpg