Parametric Investigation of the Steady-State Response of a Mechanical Seal With Two Flexibly Mounted Rotors

1999 ◽  
Vol 121 (1) ◽  
pp. 69-76 ◽  
Author(s):  
J. Wileman ◽  
I. Green
Keyword(s):  
Steady State ◽  
Dynamic Response ◽  
Parametric Analysis ◽  
Fluid Film ◽  
Steady State Response ◽  
Mechanical Seal ◽  
Film Properties ◽  
Parametric Investigation ◽  
State Dynamic ◽  
State Response

A parametric analysis is performed to investigate the steady-state dynamic response of a mechanical seal with two flexibly mounted rotors. The effect of changing various inertia, support, and fluid film properties is examined. Short rotors are shown to benefit from gyroscopic aligning moments and to exhibit their maximum steady-state misalignment when one of the shaft speeds is zero. Long rotors experience misaligning gyroscopic moments, but if only one of the two rotors is long then aligning moments from the short rotor can be transmitted through the fluid and counteract the detrimental gyroscopic effect in the long rotor. In this case rotors which corotate are shown to have a higher steady-state misalignment than those which counterrotate because of the reduction of the hydrodynamic moments, thus leading to increased leakage and a higher probability of face contact.

Steady-State Dynamic Response of a Limited Slip System

1968 ◽  
Vol 35 (2) ◽  
pp. 322-326 ◽  
Author(s):  
W. D. Iwan
Keyword(s):  
Steady State ◽  
Dynamic Response ◽  
Slip System ◽  
External Load ◽  
Initial Conditions ◽  
Viscous Damping ◽  
Steady State Response ◽  
Response Curves ◽  
State Response ◽  
System Nonlinearity

The steady-state response of a system constrained by a limited slip joint and excited by a trigonometrically varying external load is discussed. It is shown that the system may possess such features as disconnected response curves and jumps in response depending on the strength of the system nonlinearity, the level of excitation, the amount of viscous damping, and the initial conditions of the system.

Stability of a Vehicle on a Multispan Simply Supported Guideway

1978 ◽  
Vol 100 (4) ◽  
pp. 326-332 ◽  
Author(s):  
Y. I. Chung ◽  
J. Genin
Keyword(s):  
Steady State ◽  
Dynamic Response ◽  
Suspension System ◽  
Performance Criteria ◽  
Inertial Effect ◽  
Steady State Response ◽  
Span Length ◽  
Simply Supported ◽  
State Response

The dynamic response of a vehicle, with a conventional suspension system, traversing a multispan simply supported guideway system is studied parametrically. The steady state response of the system and conditions for dynamic instabilities are presented for the case where the ratio of vehicle length/span length is small. Using vehicle heave acceleration and maximum guideway deflection as performance criteria, it is shown that the interactive inertial effect is significant, even at relatively low traversing speeds.

Dynamic Response of Eccentric Face Seals to Synchronous Shaft Whirl

2004 ◽  
Vol 126 (2) ◽  
pp. 301-309 ◽  
Author(s):  
J. Wileman
Keyword(s):  
Steady State ◽  
Dynamic Response ◽  
Solution Technique ◽  
Steady State Response ◽  
Analytical Technique ◽  
State Response ◽  
Flexible Supports ◽  
Simple Matrix ◽  
The Stability ◽  
Degenerate Cases

This work provides an analytical technique for computing the seal face misalignment which results from synchronous whirl of the shaft. The eccentric dynamic response is obtained for seals in which both mating faces are mounted on flexible supports. Responses for seals with a single flexibly mounted stator or rotor are also obtained as degenerate cases of the more general result. Synchronous shaft whirl is shown to have a significant effect on the steady-state response of all these seals, while not affecting the stability threshold. The steady-state response is obtained by solution of a simple matrix equation for the general case, and can be obtained in closed form for the degenerate cases of the flexibly mounted stator or flexibly mounted rotor. A numerical example of the solution technique is presented, and the influence of speed is examined. Extension of the method to shaft motions other than synchronous whirl is briefly discussed.

Response of Cylindrical Sandwich Shells to Moving Loads

1967 ◽  
Vol 34 (1) ◽  
pp. 81-86 ◽  
Author(s):  
G. Herrmann ◽  
E. H. Baker
Keyword(s):  
Steady State ◽  
Dynamic Response ◽  
Initial Stress ◽  
Axial Stress ◽  
Steady State Response ◽  
Sandwich Shell ◽  
Moving Loads ◽  
Axially Symmetric ◽  
Cylindrical Sandwich Shell ◽  
State Response

This paper presents an analysis into the dynamic response of a long cylindrical sandwich shell under a moving axially symmetric ring load. The shell is assumed to be orthotropic and subjected to an initial axial stress. The uniform velocity of the load is prescribed and only the steady-state response is considered. Numerical results indicate the effects of various relevant parameters. The behavior of orthotropic sandwich cylinders under initial stress is compared with that of homogeneous isotropic cylindrical shells free of initial stress, and differences are pointed out.

Dynamic Response of Pressurized Thin Cylindrical Shells Subjected to Torsional Loads

1973 ◽  
Vol 95 (3) ◽  
pp. 797-802
Author(s):  
P. G. Kessel ◽  
N. K. Liao
Keyword(s):  
Steady State ◽  
Dynamic Response ◽  
Biaxial Stress ◽  
Steady State Response ◽  
Thin Cylindrical Shell ◽  
Line Load ◽  
State Response ◽  
Dynamic Loadings ◽  
Torsional Loads ◽  
Shell Geometry

This paper presents a theoretical analysis of the transient and steady-state response of a thin cylindrical shell of finite length, simply supported at both ends, under a uniform initial biaxial stress and subjected to either a circumferentially tangential harmonic point force of a sinusoidally distributed harmonic line load acting in the circumferential direction. The analyses are based on both Flugge’s and Donnell’s theories. Numerical results of the steady-state response are presented for both theories to illustrate the effects of various relevant parameters on the dynamic deflection, and to provide a direct comparison between Donnell’s and Flugge’s theories for dynamic loadings. This paper establishes the range of shell geometry for which Donnell’s equations give satisfactory results in predicting the steady-state response. The dynamic behavior after the first resonant frequency and the effect of initial stress on the dynamic response are also pointed out.

The Auditory Steady-State Response: Full-Term and Premature Neonates

2002 ◽  
Vol 13 (05) ◽  
pp. 260-269 ◽  
Author(s):  
Barbara Cone-Wesson ◽  
John Parker ◽  
Nina Swiderski ◽  
Field Rickards
Keyword(s):  
Steady State ◽  
Premature Infants ◽  
Modulation Frequency ◽  
Otoacoustic Emission ◽  
Full Term ◽  
Steady State Response ◽  
Pass Rates ◽  
Term Infants ◽  
State Response ◽  
Auditory Steady State Response

Two studies were aimed at developing the auditory steady-state response (ASSR) for universal newborn hearing screening. First, neonates who had passed auditory brainstem response, transient evoked otoacoustic emission, and distortion-product otoacoustic emission tests were also tested with ASSRs using modulated tones that varied in frequency and level. Pass rates were highest (> 90%) for amplitude-modulated tones presented at levels ≥ 69 dB SPL. The effect of modulation frequency on ASSR for 500- and 2000-Hz tones was evaluated in full-term and premature infants in the second study. Full-term infants had higher pass rates for 2000-Hz tones amplitude modulated at 74 to 106 Hz compared with pass rates for a 500-Hz tone modulated at 58 to 90 Hz. Premature infants had lower pass rates than full-term infants for both carrier frequencies. Systematic investigation of ASSR threshold and the effect of modulation frequency in neonates is needed to adapt the technique for screening.

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