| Statistical Model of Casing Treatment Triangular Recesses |
INFLUENCE OF CASING TREATMENT ON COMPRESSOR OPERATING PERFORMANCE |
INVESTIGATION OF NEW CASING TREATMENT CONFIGURATION |
BEHAVIORAL BIFURCATIONS OF AN EXACTLY SOLVABLE MODEL OF ROTORDYNAMICS |
Vitaliy Nezym
National Polytechnic Institute, Mexico
|
Vitaliy Nezym
National Polytechnic Institute, Mexico |
Vitaliy Nezym
National Polytechnic Institute, Mexico
|
Valeri V. Kucherenko, Instituto Politecnico Nacional, Mexico
Julio C. Gomez-Mancilla, Instituto Politecnico Nacional, Mexico |
| The presence of tip clearance between rotating blades and compressor casing influences unfavorably upon a stage performance. Applying of abradable inserts in the casing over rotating blades allows reducing this tip clearance practically to zero value. The variant is occurring rather frequently when rotor blade tips make an entire annular recess in this insert. A recess of triangular configuration was tested in several researches and promised a positive influence upon compressor performance. The results of two investigations were processed with the help of the Group Method of Data Handling. |
An experimental investigation has been carried out with one variant of casing treatment, an entire annular recess (EAR) over the compressor rotor blades. Various tip clearances and two groups of annular recesses (without and with penetration of rotor blade tips into casing) were used. The results for twenty such configurations are presented in the proposed paper, analyzed with respect to relative tip clearance and recess relative volume influence on compressor stable operating range. |
Mostly, casing treatment with circumferential grooves over a rotor blade tips extends a stable operation range in most cases, yet decreases compressor efficiency. The paper presents results of a parametric investigation of grooves with traditional and new configurations. Development of new groove constructions will permit combining of stable operation range extension with efficiency increase. A model on the basis of Group Method of Data Handling may help designing groove configurations with improved performances. |
Diverse cyclic responses for an effective and useful nonlinear rotor-bearing-seal system model are studied. In this work two typical cases of self-excited vibrations in turbomachinery are considered: steamwhirl, and oilwhip. The studied rotodynamic system model exhibits several mathematical bifurcations which correspond to actual machine behavior, and analysis for each autoinduced and forced excitation cases, together with its associated bifurcation, are performed. |
