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| [ 12/16/2005 ] |
| Statistical Model of Casing Treatment Triangular Recesses |
Vitaliy Nezym
National Polytechnic Institute, Mexico
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| 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. |
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| [ 11/15/2005 ] |
| INFLUENCE OF CASING TREATMENT ON COMPRESSOR OPERATING PERFORMANCE |
Vitaliy Nezym
National Polytechnic Institute, Mexico |
| 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. |
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| [ 11/15/2005 ] |
| INVESTIGATION OF NEW CASING TREATMENT CONFIGURATION |
Vitaliy Nezym
National Polytechnic Institute, Mexico
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| 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. |
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| [ 11/15/2005 ] |
| BEHAVIORAL BIFURCATIONS OF AN EXACTLY SOLVABLE MODEL OF ROTORDYNAMICS |
Valeri V. Kucherenko, Instituto Politecnico Nacional, Mexico
Julio C. Gomez-Mancilla, Instituto Politecnico Nacional, Mexico |
| 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. |
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| [ 2/8/2005 ] |
| STATISTICAL MODEL OF CASING TREATMENT INFLUENCE ON COMPRESSOR EFFICIENCY |
| Dr. Vitaliy Nezym, Professor |
| Scientists and engineers are in permanent search for improvement of axial flow compressor performance by means of design and technology advances. One of the accepted yet not comprehensively studied ways is usage of circumferential grooves over a rotor blade tips. As a rule, such casing treatment means extend a stable operation range in the most cases, but decrease compressor efficiency. The paper presents the results of parametric investigation of grooves of traditional configuration |
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