Misaligned journal effects in liquid hydrostatic non-recessed journal bearings

Jain, S. C.; Sharma, Satish C.; Nagaraju, T. Vamsi

doi:10.1016/s0043-1648(97)00038-0

Cited by 32 publications

(34 citation statements)

References 11 publications

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“…14 Also, the minimum fl uid fi lm thickness (h min ) has been computed at different values of restrictor design parameter C s2 , for hybrid mode of operation (Ω = 1.0), at fi xed external load W 0 = 1.25 and land width ratio (ā b = 0.1). These results compare well with the available results of Jain et al 16 for K = 0.0 (Newtonian case) as shown in Figure 4 and a maximum deviation of 1.9% was noted at higher vales of restrictor design parameter (C s2 ). Figure 5 shows the profi le of fl uid fi lm temperature along the circumferential direction.…”

Section: Resultssupporting

confidence: 91%

Non‐Newtonian and thermal effects in constant flow valve compensated symmetric hole‐entry hybrid journal bearing

Garg

Kumar

Sharda³

2007

Lubrication Science

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Every high speed machine, demanding high level of perfection, can operate successfully through a precise design of bearings. Such a design can be formulated after carefully studying both static and dynamic characteristics of the journal bearing. The present paper described the study of static and dynamic performance of a hole-entry hybrid journal bearing system compensated with constant fl ow valve restrictor by considering the combined infl uence of thermal effects and non-Newtonian behaviour of the lubricant. The variation of the viscosity due to the non-Newtonian behaviour of the lubricant and temperature rise has been considered in the study. The numerical solution of the generalized Reynolds equation governing the fl ow of the lubricant, having variable viscosity along with the energy and heat conduction equations, was obtained using fi nite element method. The nonNewtonian lubricant has been assumed to follow the cubic shear stress law. The study included the performance of a double row symmetric hole-entry hybrid journal bearing confi guration containing 12 holes per row. The results presented in this paper indicate that change in viscosity of lubricant affects the performance of the holeentry hybrid journal bearing system quite signifi cantly.

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Section: Resultssupporting

confidence: 91%

Non‐Newtonian and thermal effects in constant flow valve compensated symmetric hole‐entry hybrid journal bearing

Garg

Kumar

Sharda³

2007

Lubrication Science

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“…The geometry of the worn zone is shown schematically in Figure 2 given as (Dufrane et al, 1983) and the expression for non-dimensional nominal fluid-film thickness h in a worn misaligned hole-entry hybrid journal bearing system may be expressed as (Jain et al, 1997):…”

Section: Fluid-film Thicknessmentioning

confidence: 99%

“…They used the mass conserving cavitation algorithm in their analysis. Jain et al (1997) studied the influence of journal misalignment on the static and dynamic performance of a capillary compensated hole-entry hybrid journal bearing and also compared the bearing performance characteristics for two hole-entry bearing configurations. Pierre et al (2004) studied the thermohydrodynamic behavior of misaligned plain journal bearings with theoretical and experimental approaches under steady-state conditions.…”

Section: Introductionmentioning

confidence: 99%

A study of misaligned hole‐entry worn journal bearing operating in turbulent regime

Ram

Sharma

2013

Industrial Lubrication and Tribology

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Purpose -The purpose of this paper is to study theoretically the combined influence of journal misalignment and wear on the performance of a holeentry hybrid journal bearing system. The bearing is assumed to be operating in a turbulent regime. Design/methodology/approach -The modified Reynolds equation based on Constantinescu lubrication theory has been solved by using finite element method together with orifice and capillary restrictors flow equations as a constrain together with appropriate boundary conditions. Findings -It has been observed that for a symmetric hole-entry journal bearing configuration the value of h min is more for the bearing compensated by orifice restrictor as compared to capillary restrictor when bearing operates in turbulent regime under worn/unworn conditions. From the point of view of stability threshold speed v th , the reduction in the value of v th for capillary compensated bearing is around 2 3.89 percent whereas for orifice compensated bearing it is 27.85 percent when misaligned worn bearing is operating in turbulent regime.Originality/value -The present work is original of its kind, in case of misaligned hole-entry worn journal bearing. The results are quite useful for the bearing designer.

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“…The geometry and coordinate system of a hybrid hole-entry journal bearing system with a rough surface profile is shown in to journal fixed axes (x', y', 2') and is expressed (Jain, et al (1997), Singh, et al (1973)) as…”

Section: Average Fluid-film Thickness (Ht)mentioning

confidence: 99%

“…[5]) for the lubricant flow field, after adjustment for the flow through the restrictor (Eq. [6]) and modification for boundary conditions, is solved to establish the fluid-film pressure field. In the case of an orifice compensated bearing, Eq.…”

Section: Solution Proceduresmentioning

confidence: 99%

Combined Influence of Journal Misalignment and Surface Roughness on the Performance of an Orifice Compensated Non-Recessed Hybrid Journal Bearing

Sharma

Jain

Nagaraju³

2002

Tribology Transactions

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The conlbined influence of surface roughness and journal misof surface roughness parameter (A) and surface pattern paramealignnlent on the performance of an orifice contpensated holeter ( y ) for a concentric design pressure ratio /3* = 0.5. entry hybrid journal bearing system is tl~eoretically studied. The Performance is also compared to capillary and corlstant flow analysis considers the average Reynolds equation for a rough valve conlpensated bearings. The conlputed results indicate tltat srttface for the sol~ttion of the lubricant flow field in the clearance the effect ofjournal misalignment is to lower the value of the minspace of a journal hearing system. The bearing performance imum fluid-film thickness of the journal hearing system wltile the characteristics are presented for the various representative values effect of surface roughness is to partially conlpensate this loss. For the chosen values of journal misalignnlent paranteters (q~, 6), Presented at the 57th Annual Meetina tlte constant flow valve compensated syntnletric jorcrnal hearing -in Houston, Texas configuration witlz longitudinal rorcgltness pattern ( y = 6 ) shows May 2002 an improvement of around 20% in the value of stability threshold Final manuscript approved June 8,2002 Review led by Greg Kostrzewsky speed margin. = bearing land width, (a,lL) = radial clearance, bearing length = damping coefficient, Cij(c3/pR;) = stiffness coefficients, Sij(c/p,R3) (i, j = x, z,cp, 6 ) = local fluid-film thickness = nominal fluid-film thickness, (hlc) = average fluid-film thickness, (hJc) = pressure, pip,< = time, ( C~~, /~R ; ) = variance ratio, ((9. U,)/U)~ = external load, (Wo/p,Rj2) = combined roughness height, (zJ + zb)/c =journal rotational speed, threshold speed; = 0.5 correlation lengths of the x and y profile = RMS value of combined roughness = restrictor design parameter = & ( T T : / S C~~~) for capillary restrictor = +(3Td~l~~d/~3)(2/pp8)1'2 for orifice restrictor = Q, a specified value of flow for constant flow valve restrictor = coefficient of discharge for orifice = (XIR,), circumferential coordinate = (YIR,), axial coordinate =LID, aspect ratio = misalignment parameters = 2 /~ Jt exp( -y2)dy error function = speed parameter, W J (pR;/c2p,) = surface pattern parameter, (&,5rjAD,Sy) = surface roughness parameter, c / o Suesc~tprs AND SUPERSCRIPTS b = bearing J =journal S = supply -= non-dimensional parameter = first derivative w.r.t time

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Misaligned journal effects in liquid hydrostatic non-recessed journal bearings

Cited by 32 publications

References 11 publications

Non‐Newtonian and thermal effects in constant flow valve compensated symmetric hole‐entry hybrid journal bearing

Non‐Newtonian and thermal effects in constant flow valve compensated symmetric hole‐entry hybrid journal bearing

A study of misaligned hole‐entry worn journal bearing operating in turbulent regime

Combined Influence of Journal Misalignment and Surface Roughness on the Performance of an Orifice Compensated Non-Recessed Hybrid Journal Bearing

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