Download or read book Experimental Rotordynamic Characterization of Annual Seals Facility and Methodology written by J. Mark Darden and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented at the International Gas Turbine & Aeroengine Congress & Exhibition, Stockholm, Sweden, June 2 - June 5, 1998.
Download or read book Experimental Measurements and Methods for Data Analysis to Determine the Rotordynamic Coefficients of a Labyrinth Seal written by Sang Kyu Choi and published by . This book was released on 1988 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Development of an Experimental Facility for Analysis of Rotordynamic Phenomena written by Frank A. Simei and published by . This book was released on 1994 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental facility was developed to investigate the rotordynamic phenomena of rotating machinery during subcritical, resonant and supercritical operation. The behavior of the rotor was characterized throughout the operating range. The facility consists of a Bentley Nevada Corporation Rotor Kit integrated with a computerized data acquisition and control process. A LabVIEW Virtual Instrument was designed to collect, analyze and display rotor position and rotor displacement information. Experiments conducted included construction of Cascade plots, analytic prediction of the first lateral mode and demonstration of synchronous whirl due to a mass imbalance; during which, backward whirl was experienced.
Download or read book Theory Versus Experiment of the Rotordynamic and Leakage Characteristics of Smooth Annular Bushing Oil Seals written by Vittorio G Culotta and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis provides a comparison of experimental rotordynamic coefficients for laminar, smooth bushing oil seals to theoretical predictions from XLLubeGT and XLAnSeal. The experimental results come from a new test rig developed at the Turbomachinery Laboratory at Texas A & M University. The two software programs were developed to predict the static and dynamic characteristics of seals. XLLubeGT is a Reynolds equation based program while XLAnSeal is based on a bulk-flow Navier-Stokes model that includes temporal and convective acceleration terms. XLAnSeal was used to predict the added-mass terms of the seals since XLLubeGT assumes those terms to be zero or negligible. The data used for input into the two seals code was the actual measured conditions from the test rig. As part of the input parameters, inlet inertia effects and thermal gradients along the seal were included. Both XLLubeGT and XLAnSeal have the capability to analyze straight bore seals with different inlet and outlet clearances - essentially a tapered seal - but seal expansion caused by the radial differential pressure across the seal bushing was not included. Theoretical and experimentally determined dynamic characteristics include stiffness, damping, inertia terms and Whirl Frequency Ratio (WFR). Seal static characteristics are also reported. They include: leakage, shaft center line loci and Reynolds numbers. Test conditions include three shaft speeds: 4000, 7000 and 10,000 rpm, three test pressures: 21, 45 and 69 bar [300, 650, and 1000 psi] and multiple eccentricities from 0.0 to 0.7. The results for the dynamic characteristics show good correlation of the experimental data to the theoretical values up to an eccentricity of about 0.5. At higher eccentricities, the theory generally under-predicts the dynamic characteristics. Inertia terms are greatly under-predicted. The results for the static characteristics also show good correlation to the experimental data, but they also have a tendency to be under-predicted at higher eccentricities.
Download or read book Rotordynamics written by Agnieszka Muszynska and published by CRC Press. This book was released on 2005-05-20 with total page 1100 pages. Available in PDF, EPUB and Kindle. Book excerpt: As the most important parts of rotating machinery, rotors are also the most prone to mechanical vibrations, which may lead to machine failure. Correction is only possible when proper and accurate diagnosis is obtained through understanding of rotor operation and all of the potential malfunctions that may occur. Mathematical modeling, in particular
Download or read book Rotordynamic Properties of High Pressure Seals written by Tachung Yang and published by . This book was released on 1989 with total page 966 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Preprints Presented at the STLE Annual Meeting written by and published by . This book was released on with total page 676 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Rotordynamic Coefficient Results for Honeycomb Seals written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Test results (leakage and rotordynamic coefficients) are presented for seven honeycomb-stator smooth-rotor seals. Tests were carried out with air at rotor speeds up to 16,000 cpm and supply pressures up to 8.2 bars. Test results for the seven seals are compared, and the most stable configuration is identified based on the whirl frequency ratio. Results from tests of a smooth-rotor/smooth-stator seal, a teeth-on-stator labyrinth seal, and the most stable honeycomb seal are compared. Elrod, David A. and Childs, Dara W. Unspecified Center AERODYNAMIC COEFFICIENTS; HONEYCOMB STRUCTURES; LABYRINTH SEALS; LEAKAGE; ROTOR AERODYNAMICS; STATORS; COMPARISON; TABLES (DATA); TEST EQUIPMENT...
Download or read book A Comparison of Experimental Rotordynamic Coefficients and Leakage Characteristics Between Hole pattern Gas Damper Seals and a Honeycomb Seal written by Zeping Yu and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented at the International Gas Turbine & Aeroengine Congress & Exhibition, Orlando, FL, Jun 2-Jun 5, 1997.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1985 with total page 1156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Measurements Versus Predictions for Rotordynamic Coefficients and Leakage Rates for a Novel Hole pattern Gas Seal written by Brent Alan Seifert and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Results are presented for measured and predicted rotordynamic coefficients and leakage for hole-pattern seals with a hole depth that varies axially along the seal. Testing was done to discover how pressure ratio, inlet preswirl, and rotor speed affect the seals' rotordynamic characteristics and leakage. The results were compared to a constant hole depth hole-pattern seal. Experimental results show that the seals' rotordynamic characteristics are not strongly influenced by pressure ratio. There were three preswirl conditions tested, each separated by a 6.9 bar (100psi) difference in inlet pressure. Therefore, normalized preswirl results were compared. The normalized results indicate that introducing inlet fluid preswirl affects the cross coupled stiffness and effective damping coefficients. Inlet preswirl increases the magnitude of cross-coupled stiffness. Effective damping decreases with inlet preswirl, as well as the effective damping cross-over frequency increasing. These results indicate that swirl brakes would be of great value. Rotor speed had a significant effect on the cross-coupled coefficients; both increased with speed. Experimental results were compared to results for a constant hole depth hole pattern seal. The variable hole-depth seal has higher direct damping. The cross-coupled stiffness and cross-coupled damping coefficients were very similar. The direct stiffness was always lower at lower frequencies and higher at higher frequencies for the variable hole depth hole-pattern seal. This was also the case for effective stiffness. The effective damping of the variable hole-depth seal was not only larger than for the constant hole depth seal, it also had a drastically lower cross-over frequency. The difference in cross-over frequency was 40 percent on average. Experimental results for rotordynamic characteristics and leakage were compared to theoretical predictions by ISOTSEAL 2, a modified version of ISOTSEAL. Both cross-coupled stiffness and damping are reasonably predicted. Direct damping is always under-predicted. ISOTSEAL 2 does a poor job of predicting direct stiffness. Direct stiffness is over-predicted at lower frequencies and under-predicted at higherfrequencies. This is also the case for effective stiffness. ISOTSEAL 2 under-predicts the direct damping, but does an excellent job of predicting the direct damping crossover frequency. Seal leakage is well predicted by ISOTSEAL 2.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 934 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental and Theoretical Rotordynamic Coefficients and Leakage of Straight Smooth Annular Gas Seals written by Bradley Gray Kerr and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Results are presented for experimental and theoretical rotordynamic coefficients and leakage of straight smooth annular gas seals. Experimental rotordynamic coefficients were measured and trends in changes of rotordynamic coefficients with operating variables such as rotor speed, back-pressure, fluid preswirl, and seal clearance are analyzed. Experimental results show that cross-coupled stiffness coefficients are highly influenced by fluid preswirl and only moderately influenced by other operating parameters, whereas direct damping is nearly unaffected by changes in operating parameters. Effective damping, a good indicator of stability, is highly affected by fluid preswirl. Although rotordynamic coefficients of straight smooth annular gas seals are assumed to be frequency independent, experimental results suggest a frequency dependent nature at high back-pressures and high excitation frequencies. Experimental results for rotordynamic coefficients and leakage are compared with theoretical predictions of ISOTSEAL, an isothermal-flow, two-control-volume, bulk-flow rotordynamic analysis program. All rotordynamic coefficients are underpredicted. Direct stiffness is poorly predicted while cross-coupled stiffness and direct damping are predicted reasonably well. Leakage is also consistently under-predicted. Theory predicts a slight frequency dependent nature for a limited number of test configurations.
Download or read book Development of a Rotating Test Facility for the Experimental Characterisation of Turbomachinery Shaft Seals written by Ernesto Pedraza-Valle and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1995 with total page 1100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Rotordynamic and Leakage Characteristics of a 4 Stage Brush Seal written by and published by . This book was released on 1992 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental results are presented for the direct and cross-coupled stiffness and damping coefficients as well as the leakage performance for a 4- stage brush seal. Variable test parameters include the inlet pressure, pressure ratio, shaft speed, fluid prerotation, and seal spacing. Direct damping is shown to increase with running speed; otherwise, the rotordynamic coefficients are relatively insensitive to changes in the test parameters. Cross-coupled stiffness is generally unchanged by increasing the inlet tangential velocity to the seals, suggesting that the brush seal is not affected by inlet swirl. Direct stiffness is shown to increase with frequency; however, the magnitudes of direct stiffness are always positive. Cross-coupled stiffness increases slightly with frequency; yet not as drastically as dire stiffness. Comparisons of test results for the 4-stage brush seal with an 8-cavity labyrinth showed superior rotordynamics performance for the brush seal; viz., large values for direct stiffness and lower values for the (destabilizing) cross-coupled stiffness coefficient. The damping for brush seals is smaller, but comparable to labyrinth seals. The whirl-frequency ratio is always smaller for the brush seal. Brush seal, Rotordynamics, Seal, Turbine.
