View source for Nonlinear Control of Rotating Stall and Surge with Axisymmetric Bleed and Air Injection on Axial Flow Compressors

{{HTDB paper
| authors = Chung-hei (Simon) Yeung
| title = Nonlinear Control of Rotating Stall and Surge with Axisymmetric Bleed and Air Injection on Axial Flow Compressors
| source = PhD Dissertation, Caltech, August 1998
| year = 
| type = 
CDS Technical Report
| funding = AFOSR
| url = http://www.cds.caltech.edu/~murray/preprints/chy98-phd.pdf
| abstract = 
The study of compressor instabilities in gas turbine engines has received
much attention in recent years.  In particular, rotating stall and surge
are major causes of problems ranging from component stress and lifespan
reduction to engine explosion.  In this thesis, modeling and control of
rotating stall and surge using bleed valve and air injection is studied and
validated on a low speed, single stage, axial compressor at Caltech.
<p>
Bleed valve control of stall is achieved only when the compressor
characteristic is actuated, due to the fast growth rate of the stall cell
compared to the rate limit of the valve.  Furthermore, experimental results
show that the actuator rate requirement for stall control is reduced by a
factor of fourteen via compressor characteristic actuation.  Analytical
expressions based on low order models (2--3 states) and a high fidelity
simulation (37 states) tool are developed to estimate the minimum rate
requirement of a bleed valve for control of stall.  A comparison of the
tools to experiments show a good qualitative agreement, with increasing
quantitative accuracy as the complexity of the underlying model increases.
<p>
Air injection control of stall and surge is also investigated.
Simultaneous control of stall and surge is achieved using axisymmetric air
injection.  Three cases with different injector back pressure are studied.
Surge control via binary air injection is achieved in all three cases.
Simultaneous stall and surge control is achieved for two of the cases, but
is not achieved for the lowest authority case.  This is consistent with
previous results for control of stall with axisymmetric air injection
without a plenum attached.
<p>
Non--axisymmetric air injection control of stall and surge is also studied.
Three existing control algorithms found in literature are modeled and
analyzed.  A three--state model is obtained for each algorithm.  For two
cases, conditions for linear stability and bifurcation criticality on
control of rotating stall are derived and expressed in terms of
implementation--oriented variables such as number of injectors.  For the
third case, bifurcation criticality conditions are not obtained due to
complexity, though linear stability property is derived.  A theoretical
comparison between the three algorithms is made, via the use of low--order
models, to investigate pros and cons of the algorithms in the context of
operability.
<p>
The effects of static distortion on the compressor facility at Caltech is
characterized experimentally.  Results consistent with literature are
obtained.  Simulations via a high fidelity model (34 states) are also
performed and show good qualitative as well as quantitative agreement to
experiments.  A non--axisymmetric pulsed air injection controller for stall
is shown to be robust to static distortion.
| flags = 
| tag = chy98-phd
| id = 1998
}}