Experimental Study of Dynamic Fluid Forces and Moments for a Long Annular Seal

Kanemori, Yuji; Iwatsubo, Takuzo

doi:10.1115/1.2920947

Cited by 30 publications

(9 citation statements)

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“…Childs [5,6] proposed a finite-length method to calculate the dynamic coefficients of annular seals based on the Hirs' turbulent lubrication equations and perturbation method, and this method has been widely applied to the analysis of the stable motion of rotor-bearing-seal system. Kanemori and Iwatsubo [7,8] conducted groups of experiments to research the dynamic coefficients of long annular seals at various rotating speeds, whirling speeds, and pressure drops, they found the experimental results coincided fairly well with Childs' theory. However, the Childs' linear model will be no longer applicable in the case of large disturbance.…”

Section: Introductionmentioning

confidence: 78%

A coupling vibration model of multi-stage pump rotor system based on FEM

Wang¹,

Zhou²,

Wei³

et al. 2016

mech

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Section: Introductionmentioning

confidence: 78%

A coupling vibration model of multi-stage pump rotor system based on FEM

Wang¹,

Zhou²,

Wei³

et al. 2016

mech

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“…Subsequently from distribution of the radial and tangential forces depending on the rotation were determined mean values of F r F t [1], [2], [3]. Thus defined procedure of evaluation forces was carried out for all combinations of rotation and precession.…”

Section: )mentioning

confidence: 99%

Investigation of viscous fluid flow in an eccentrically deposited annulus using CFD methods

Bojko

Kozdera

Kozubková

2013

EPJ Web of Conferences

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Abstract. The theory of fluid flow in an eccentrically deposited annulus has of great importance especially in the design of sliding bearings (axial, radial). If the geometry is more complex or shaft is deposited eccentrically, then a suitable alternative for design hydrostatic bearing is using ANSYS Fluent, which solves the general three-dimensional viscous fluid flow also in complex geometry. The problem of flow solves in the narrow gap between the cylinders in this paper, when the inner cylinder is stored with a defined eccentricity. The movement of the inner cylinder is composed of two motions (rotation, precession), i.e. rotation around its own axis and move along the circle whose radius is the size of the eccentricity. Addition the pressure gradient is considered in the axial direction. In the introductory section describes the methodology for defining of motions (rotation and precession of the inner cylinder) when the user function (UDF) is created that defines the rotation and move along the circle in C++. The above described methodology of the solution was then applied to the 3D model with a defined pressure drop when the problem was solved as a time-dependent with a time value corresponding to two turns of the internal shaft.

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“…4 On the other hand, the integral equation with a logarithmic kernel has been proved to easily perform the numerical computation by Cheung and Chen. 5 This method with weak singularity has been used to solve some crack problems associated with an elastic half-plane medium, 6 two bonded thermoelastic half-plane media, 7 and thermoelastic circular inclusion perfectly bonded in an in® nite matrix. 8 Based on the earlier derivation,Chen and Cheung 9 recently reformulateda new boundaryintegralequationto deal with the notch problem in plane elasticity.…”

Section: Introductionmentioning

confidence: 99%

Three-Dimensional Finite Difference Method for Rotordynamic Fluid Forces on Seals

et al. 1997

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does not predict a streamwise stress level that is signi® cantly higher than the simulation of Beaudan and Moin. 5 However, this can be explainedby noting that, for this¯ow, most of the contributionto the Reynolds stress comes from¯uctuationsin a narrow frequencyband extending from about 0.5x s t to 3.0x st , and in this frequency band, the energy in both simulations is comparable. Thus, even though the simulations of Beaudan and Moin 5 exhibit signi® cant damping of the higher frequencies,this does not have a signi® cant impact on the low-order turbulence statistics.By comparing the vertical stress pro® les at these locations, we observe that prediction from the two simulations at x/ D = 7.0 is quite similar. At x/ D = 10.0, the two simulations predict roughly the same peak stress level; however, the shape of the experimental pro® le matches the pro® le of Beaudan and Moin 5 better than it does for the current simulation. Furthermore, we have found that vertical velocity and shear stress pro® les (not shown here) from both the simulations are also in reasonable agreement with experiments. 11 ConclusionsIt is found that in the downstream portion of the wake, where the grid is relatively coarse, the numerical dissipation inherent in the higher-order upwind-biased schemes removes substantial energy from roughly three-quarters of the resolved wave number range. In the central difference simulation, because there is no numerical dissipation, the smaller scales are more energetic. Because of this reduction in the damping of smaller scales, we ® nd that the computed power spectra agree well with the experiment up to about half of the resolved wave number range. However, the enhanced energy in the small scales has no signi® cant effect on the low-order statistics, and the mean velocity and Reynolds stress pro® les in this region obtained from the two simulations are comparable. This is because most of the contribution to the normal stress comes from uctuations whose frequency is centered in a narrow band around the shedding frequency and change in the energy of the small scales does not have a signi® cant effect on the magnitudes of the Reynolds stresses. However, in applications such as¯ow generated noise and reactive¯ows, small-scale¯uctuations play a crucial role, and it is, therefore, critical to retain the energy in the small scales. In such applications,energy conservativeschemes would be preferableover upwind schemes. We also ® nd that with about 20±30% smaller grid spacing, the second-order central difference scheme gives results that are comparable to those obtained by the high-order upwind biased schemes. The higher-order upwind based solver is more expensive on a per-pointbasis than the second-ordercentral difference solver, and this partially offsets the additional cost of the increased resolution required by the second-order method. A drawback of the second-order central scheme is that the simulations are sensitive to numerical factors such as grid discontinuities and out¯ow boundary conditions and, thus, g...

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Experimental Study of Dynamic Fluid Forces and Moments for a Long Annular Seal

Cited by 30 publications

References 0 publications

A coupling vibration model of multi-stage pump rotor system based on FEM

A coupling vibration model of multi-stage pump rotor system based on FEM

Investigation of viscous fluid flow in an eccentrically deposited annulus using CFD methods

Three-Dimensional Finite Difference Method for Rotordynamic Fluid Forces on Seals

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