A bulk-flow analysis of static and dynamic characteristics of floating ring seals

2007 ◽  
Vol 40 (3) ◽  
pp. 470-478 ◽  
Author(s):  
Wenbo Duan ◽  
Fulei Chu ◽  
Chang-Ho Kim ◽  
Yong-Bok Lee
Keyword(s):  
Dynamic Characteristics ◽  
Flow Analysis ◽  
Bulk Flow ◽  
Static And Dynamic Characteristics

Test Results for the Static and Rotordynamic Characteristics of a Long (L/D = 0.75) Smooth Seal in Two-Phase (Mainly Gas) Conditions With a 62-Bar Inlet Pressure

2020 ◽  
Author(s):  
Dung L. Tran ◽  
Dara W. Childs ◽  
Hari Shrestha ◽  
Min Zhang
Keyword(s):  
Dynamic Characteristics ◽  
Gas Turbines ◽  
Flow Model ◽  
Dynamic Stiffness ◽  
Bulk Flow ◽  
Liquid Volume ◽  
Test Results ◽  
Two Phase ◽  
Static And Dynamic Characteristics ◽  
San Andres

Abstract Recent multiphase-pump developments encountered several rotordynamic issues with smooth balance-piston seals, creating a need to better understand the performance of annular seals under multiphase-flow operation. This paper presents measurements of static and dynamic characteristics of a long smooth seal (L/D = 0.75, D = 114.686 mm, and Cr = 0.200 mm) operating under pure- and mainly air condition in which air is mixed with silicone oil (PSF-5cSt). Tests are performed at a supply pressure of 62.1 bars-a, three rotation speeds (5, 10, 15 krpm), three pressure ratios (PRs) (0.6, 0.5, 0.4), for a range of inlet liquid volume fraction (LVFi) from 0% to 8%. The results are then compared to: (1) the previous test reported by Zhang et al. (2017, “Experimental Study of the Static and Dynamic Characteristics of a Long Smooth Seal with Two-Phase, Mainly-air Mixtures,” J. Eng. Gas Turbines Power, 139(12), p. 122504) with similar testing condition but a different seal geometry (L/D = 0.65, D = 89.306 mm, and Cr = 0.188 mm) and (2) the predictions from a bulk-flow model developed by San Andrés (2012, “Rotordynamic Force Coefficients of Bubbly Mixture Annular Pressure Seals,” ASME J. Eng. Gas Turbines Power, 134(2), p. 022503). Results show a significant increase of direct dynamic stiffness KΩ as LVFi increases, especially at low PR. Test results reported by Zhang et al. (2017) has an opposite tendency of KΩ as an impact of increasing LVFi. Concerning cross-coupled dynamic stiffness kΩ and cross-coupled damping c, the results from Zhang et al. (2017) and the present results agree to the effects of changing speed, PR, and LVFi under pure- and mainly air conditions. As LVFi increases, direct damping C increases while test results reported by Zhang et al. (2017) showed no significant increase. Except for the direct dynamic stiffness and the impact of changing LVFi on the cross-coupled dynamic stiffness, the bulk-flow model of San Andrés (2012) predicts decently the tendencies and magnitudes of the rotordynamic coefficients.

Combined Navier–Stokes and Bulk-Flow Analysis of Hybrid Bearings: Radial and Angled Injection

2004 ◽  
Vol 127 (3) ◽  
pp. 557-567 ◽  
Author(s):  
M. Hélène ◽  
M. Arghir ◽  
J. Frêne
Keyword(s):  
Dynamic Characteristics ◽  
Flow Model ◽  
Pressure Field ◽  
Flow Analysis ◽  
Bulk Flow ◽  
Navier Stokes ◽  
Favourable Effect ◽  
Alternative Analysis ◽  
Pressure Pattern ◽  
Numerical Predictions

The present work deals with the Navier–Stokes and bulk-flow analysis of hybrid bearings intended for use in aerospace applications. These bearings are expected to work at high rotational speeds and high feeding pressures. In such a case, the pressure in the shallow pockets of the bearing is no longer constant and is influenced by hydrostatic and hydrodynamic effects. It has been shown in the literature that the recess pressure pattern can have an important influence on the dynamic characteristics of the bearing. The present work investigates the pressure field in the recess of centered hybrid bearings with radial and angled injection by using a numerical Navier–Stokes analysis. The recess pressure pattern is then subsequently characterized by combining these results with some parametric descriptions. For calculating the dynamic characteristics of the bearing, the parametric pressure pattern is then injected into a bulk-flow model. The proposed model is an alternative analysis to the one advanced by San Andrés [ASME J. Tribole, 112, pp. 699–707; 119, 179–187] and in order to evaluate the validity of the bulk-flow code, the numerical predictions are compared with experimental data taken from the literature for radial and angled injection. The favourable effect of the counter-rotating angled injection is then explained by using the velocity field issued from the Navier–Stokes analysis and the pressure field given by the bulk-flow model.

Combined Navier-Stokes and Bulk-Flow Analysis of Hybrid Bearings: Radial and Angled Injection

2004 ◽  
Author(s):  
Mathieu Helene ◽  
Mihai Arghir ◽  
Jean Frene
Keyword(s):  
Dynamic Characteristics ◽  
Flow Model ◽  
Pressure Field ◽  
Flow Analysis ◽  
Bulk Flow ◽  
Navier Stokes ◽  
Favorable Effect ◽  
Alternative Analysis ◽  
Pressure Pattern ◽  
Numerical Predictions

The present work deals with the Navier-Stokes and bulk-flow analysis of hybrid bearings intended for use in aerospace applications. These bearings are expected to work at high rotational speeds and high feeding pressures. In such a case, the pressure in the shallow pockets of the bearing is no longer constant and is influenced by hydrostatic and hydrodynamic effects. It has been shown in the literature that the recess pressure pattern can have an important influence on the dynamic characteristics of the bearing. The present work investigates the pressure field in the recess of centered hybrid bearings with radial and angled injection by using a numerical Navier Stokes analysis. The recess pressure pattern is then subsequently characterized by combining these results with some parametric descriptions. For calculating the dynamic characteristics of the bearing, the parametric pressure pattern is then injected into a bulk-flow model that is an alternative analysis of the one introduced by San Andre´s [3, 4]. In order to evaluate the validity of the bulk-flow code, the numerical predictions are compared with experimental data taken from the literature for radial and angled injection. The favorable effect of the counter-rotating angled injection is then explained by using the velocity field issued from the Navier Stokes analysis and the pressure field given by the bulk-flow model.

Calibration of a Design Tool for Dynamic Characteristics of Gas Labyrinth Seals

2016 ◽  
Author(s):  
R. Gordon Kirk ◽  
Wen Jeng Chen
Keyword(s):  
High Pressure ◽  
Dynamic Characteristics ◽  
Critical Path ◽  
Flow Analysis ◽  
Labyrinth Seal ◽  
Design Tool ◽  
Bulk Flow ◽  
System Stability ◽  
Prior Work ◽  
Labyrinth Seals

The analysis of all critical path high pressure machinery must include the account of the influence of the gas labyrinth seals. This paper reviews the prior work on labyrinth seal analysis starting in the 1980’s. The discussion gives a summary of the calibration of the bulk flow analysis to CFD results for a number of conditions. The calibration process was conducted over the last decade and the current paper presents the key results needed to justify the use of this bulk flow analysis for design of machinery with bladed labyrinth seals. A new design tool is discussed with illustrations of the type of seals that can be studied. The dynamic characteristics calculated using the labyrinth seal program can be used in rotordynamic analysis programs to predict the change in system stability produced by the gas labyrinth seals.

Invited PaperTemperature dependence of SiGe HBT static and dynamic characteristics

1998 ◽  
Vol 08 (PR3) ◽  
pp. Pr3-81-Pr3-86
Author(s):  
F. Aniel ◽  
N. Zerounian ◽  
A. Gruhle ◽  
C. Mähner ◽  
G. Vernet ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Static And Dynamic Characteristics ◽  
Sige Hbt

Analysis and Optimization of the Static and Dynamic Characteristics of Head Frame

2011 ◽  
Vol 418-420 ◽  
pp. 2055-2059 ◽  
Author(s):  
Yu Lin Wang ◽  
Na Jin ◽  
Kai Liao ◽  
Rui Jin Guo ◽  
Hu Tian Feng
Keyword(s):  
Machine Tool ◽  
Dynamic Characteristics ◽  
Maximum Stress ◽  
Dynamic Performance ◽  
Mode Shapes ◽  
Cnc Machine ◽  
Static And Dynamic Characteristics ◽  
Maximum Deformation ◽  
Improvement Measures ◽  
Optimal Measure

The head frame is a key component which plays a supportive and accommodative role in the spindle system of CNC machine tool. Improving the static and dynamic characteristics has profound significance to the development of machine tool and product performance. The simplified finite element modal is established with ANSYS to carry out the static and modal analysis. The results showed that the maximum deformation of the head frame was 0.0066mm, the maximum stress was 3.94Mpa, the deformation of most region was no more than 0.0007mm, which all verified that the head frame had a good stiffness and deforming resistance; several improvement measures for dynamic performance were also proposed by analyzing the mode shapes, and the 1st order natural frequency increased 7.33% while the head frame mass only increased 1.58% applying the optimal measure, which improved the dynamic characteristics of the head frame effectively.

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