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1
Content available Inertia effects in a multilobe conical bearing lubricated with a couple stress fluid
Walicka A., Walicki E., Jurczak P.
International Journal of Applied Mechanics and Engineering
|
2019
|
Vol. 24, no. 2
439--451
EN
In this paper, a multilobe conical bearing is analyzed. A lubricant modelled by a couple stress fluid flows In the bearing clearance . The Galerkin method is used to determine the mechanical parameters of multilobe journal bearings. An example of a two-lobe conical bearing is discussed in detail. The inertia of the flowing lubricant is taken into account in the analysis. It has been found that the increase of the couple stress generates an increase the pressure in the clearance.
2
Content available remote Effects of Hindrance Factors on a Squeeze Film of a Porous Bearing Lubricated With a Dehaven Fluid
Walicka A., Walicki E., Jurczak P., Falicki J.
Machine Dynamics Research
|
2018
|
Vol. 42, No. 1
15--33
EN
In the paper the influence of the hindrance factors on the pressure distribution and loadcarrying capacity of a curvilinear thrust porous bearing is discussed. The equations of motion of a pseudo-plastic fluid of DeHaven are used to derive the Reynolds equation. The general considerations on the flow in a bearing clearance were presented. The analytical considerations on the flow in a thin porous layer composed of capillaries were also presented. Two models of the porous region were used, e.g.: capillary tube with constant cross-section and capillary tube with variable cross-section with rectilinear generatrices. Next, using the Morgan-Cameron approximation the modified Reynolds equation was obtained. As a result the formulae expressing pressure distribution and load-carrying capacity were obtained. Thrust radial bearing with a squeeze film of DeHaven fluid was considered as an example.
3
Content available Mechanical parameters of the curvilinear squeeze film bearing lubricated by a Gecim-Winer fluid
Walicka A., Walicki E.
International Journal of Applied Mechanics and Engineering
|
2017
|
Vol. 22, no. 2
465--473
EN
Based upon a Gecim-Winer fluid flow model, a curvilinear squeeze film bearing is considered. The equations of motion are given in a specific coordinates system. After general considerations on the Gecim-Winer fluid flow these equations are used to derive the Reynolds equation. The solution of this equation is obtained by a method of successive approximation. As a result one obtains formulae expressing the pressure distribution and load-carrying capacity. The numerical examples of the Gecim-Winer fluid flow in gaps of two simple bearings: radial and spherical are presented.
4
Content available Influence of wall porosity and surfaces roughness on the steady performance of an externally pressurized hydrostatic conical bearing lubricated by a Rabinowitsch fluid
Walicka A., Walicki E., Jurczak P., Falicki J.
International Journal of Applied Mechanics and Engineering
|
2017
|
Vol. 22, no. 3
717--737
EN
In the paper, the influence of both the bearing surfaces roughness as well as porosity of one bearing surface on the pressure distribution and load-carrying capacity of a curvilinear, externally pressurized, thrust bearing is discussed. The equations of motion of a pseudo-plastic Rabinowitsch fluid are used to derive the Reynolds equation. After general considerations on the flow in a bearing clearance and in a porous layer using the Morgan-Cameron approximation and Christensen theory of hydrodynamic lubrication with rough bearing surfaces the modified Reynolds equation is obtained. The analytical solution is presented; as a result one obtains the formulae expressing the pressure distribution and load-carrying capacity. Thrust radial and conical bearings, externally pressurized, are considered as numerical examples.
5
Content available Curvilinear squeeze film bearing with porous wall lubricated by a Rabinowitsch fluid
Walicka A., Walicki E., Jurczak P., Falicki J.
International Journal of Applied Mechanics and Engineering
|
2017
|
Vol. 22, no. 2
427--441
EN
The present theoretical analysis is to investigate the effect of non-Newtonian lubricant modelled by a Rabinowitsch fluid on the performance of a curvilinear squeeze film bearing with one porous wall. The equations of motion of a Rabinowitsch fluid are used to derive the Reynolds equation. After general considerations on the flow in a bearing clearance and in a porous layer using the Morgan-Cameron approximation the modified Reynolds equation is obtained. The analytical solution of this equation for the case of a squeeze film bearing is presented. As a result one obtains the formulae expressing pressure distribution and load-carrying capacity. Thrust radial bearing and spherical bearing with a squeeze film are considered as numerical examples.
6
Content available Mechanical parameters of the squeeze film curvilinear bearing lubricated with a Prandtl fluid
Walicka A., Walicki E.
International Journal of Applied Mechanics and Engineering
|
2016
|
Vol. 21, no. 4
967--978
EN
Based upon a Prandtl fluid flow model, a curvilinear squeeze film bearing is considered. The equations of motion are given in a specific coordinate system. After general considerations on the Prandtl fluid flow these equations are used to derive the Reynolds equation. The solution of this equation is obtained by a method of successive approximation. As a result one obtains formulae expressing the pressure distribution and load-carrying capacity. The numerical examples of the Prandtl fluid flow in gaps of two simple bearings are presented.
7
Content available Thrust porous bearing with rough surfaces lubricated by a rotem-shinnar fluid
Walicka A., Walicki E.
Acta Mechanica et Automatica
|
2016
|
Vol. 10, no. 1
50--55
EN
In the paper the influence of both bearing surfaces roughness and porosity of one bearing surface on the pressure distribution and load-carrying capacity of a thrust bearing surfaces is discussed. The equations of motion of a pseudo-plastic fluid of Rotem-Shinnar, are used to derive the Reynolds equation. After general considerations on the flow in a bearing clearance and in a porous layer using the Morgan-Cameron approximation and Christensen theory of hydrodynamic lubrication the modified Reynolds equation is obtained. The analytical solutions of this equation for the cases of squeeze film bearing and externally pressurized bearing are presented. As a result one obtains the formulae expressing pressure distribution and load-carrying capacity. Thrust radial bearing with squeezed film is considered as a numerical example.
8
Parametry mechaniczne wielokrzywkowego stożkowego łożyska smarowanego płynem z naprężeniami momentowymi
Walicka A., Jurczak P., Walicki E., Wojnarowski J.
Zeszyty Naukowe. Mechanika / Politechnika Opolska
|
2015
|
z. 106
93
PL
Dodatki uszlachetniające dodawane do olejów smarnych powodują tak duże zmiany ich właściwości przepływowych, że stają się płynami nienewtonowskimi. Jednym z takich płynów jest płyn z naprężeniami momentowymi. W pracy rozważane jest stożkowe łożysko wielokrzywkowe smarowane płynem z naprężeniami momentowymi. Przepływ oleju smarującego określa odpowiednio zmodyfikowane równanie Reynoldsa. Aby uzyskać rozwiązanie tego równania, zastosowano metodę Galerkina. W rezultacie otrzymano formuły określające parametry mechaniczne rozważanego łożyska.
9
Efekty bezwładnościowe w hydrostatycznym łożysku wzdłużnym o chropowatych powierzchniach
Walicka A., Jurczak P., Walicki E., Wojnarowski J.
Zeszyty Naukowe. Mechanika / Politechnika Opolska
|
2015
|
z. 106
92
PL
Rozważania teoretyczne, a także większość badań eksperymentalnych, odnoszących się do łożysk ślizgowych dotyczy przypadku idealnie gładkich powierzchni; w rzeczywistości powierzchnie łożysk ślizgowych są zawsze chropowate. Bezwładność oleju smarnego przepływającego w szczelinie hydrostatycznego łożyska wzdłużnego ma istotny wpływ na parametry mechaniczne łożyska. W pracy przedstawiono równanie Reynoldsa uwzględniające zarówno bezwładność przepływającego środka smarnego jak i chropowatość powierzchni roboczych łożyska hydrostatycznego wzdłużnego; w wyniku rozwiązania równania Reynoldsa określono parametry mechaniczne łożyska.
10
Content available remote Mechanical Parameters for a Multilobe Conical Bearing Lubricated with a Couple-Stress Fluid
Walicka A., Walicki E., Jurczak P., Wojnarowski J.
Machine Dynamics Research
|
2015
|
Vol. 39, No. 4
43-54
EN
In this paper a solution to the problem of mechanical parameters of a multilobe journal bearing is presented. The problem is solved by the Galerkin method after assuming that the bearing is lubricated with a couple-stress fluid. An example of a two-lobe bearing is discussed in detail. It was found that the presence of couple-stresses affects considerably an increase in the film pressure.
11
Content available Thrust bearing with rough surfaces lubricated by an Ellis fluid
Walicka A., Walicki E., Jurczak P., Falicki J.
International Journal of Applied Mechanics and Engineering
|
2014
|
Vol. 19, no. 4
809--822
EN
In the paper the influence of bearing surfaces roughness on the pressure distribution and load-carrying capacity of a thrust bearing is discussed. The equations of motion of an Ellis pseudo-plastic fluid are used to derive the Reynolds equation. After general considerations on the flow in a bearing clearance and using the Christensen theory of hydrodynamic rough lubrication the modified Reynolds equation is obtained. The analytical solutions of this equation for the cases of a squeeze film bearing and an externally pressurized bearing are presented. As a result one obtains the formulae expressing pressure distribution and load-carrying capacity. A thrust radial bearing is considered as a numerical example.
12
Content available Porous squeeze film bearing with rough surfaces lubricated by a Bingham fluid
Walicka A., Walicki E., Jurczak P., Falicki J.
International Journal of Applied Mechanics and Engineering
|
2014
|
Vol. 19, no. 4
795--808
EN
In the paper the effect of both bearing surfaces and the porosity of one bearing surface on the pressure distribution and load-carrying capacity of a squeeze film bearing is discussed. The equations of motion of a Bingham fluid in a bearing clearance and in a porous layer are presented. Using the Morgan-Cameron approximation and Christensen theory of rough lubrication the modified Reynolds equation is obtained. The analytical solutions of this equation for a squeeze film bearing are presented. As a result one obtains the formulae expressing pressure distribution and load-carrying capacity. A thrust radial bearing is considered as a numerical example.
13
Content available remote Pressure distribution in a porous squeeze film bearing lubricated by a simple Casson fluid
Walicka A., Walicki E., Jurczak P.
International Journal of Applied Mechanics and Engineering
|
2012
|
Vol. 17, no. 3
1039-1049
EN
The influence of a wall porosity on the pressure distribution in a curvilinear squeeze film bearing lubricated by a lubricant being a viscoplastic fluid of a simple Casson type is considered. After general considerations on the flow of the viscoplastic fluid (lubricant) in a bearing clearance and in a porous layer the modified Reynolds equation for the curvilinear squeeze film bearing with a Casson lubricant is given. The solution of this equation is obtained by a method of successive approximation. As a result one obtains a formula expressing the pressure distribution. The example of squeeze film in a step bearing (modeled by two parallel disks) is discussed in detail.
14
Content available remote Inertia effects in a porous squeeze film bearing lubricated by a Bingham fluid
Walicka A., Walicki E., Jurczak P.
International Journal of Applied Mechanics and Engineering
|
2012
|
Vol. 17, no. 3
1027-1038
EN
The influence of inertia and wall porosity on the pressure distribution in a curvilinear squeeze film bearing lubricated by a viscoplastic fluid of a Bingham type is considered. The general consideration on the flow of the viscoplastic fluid in a bearing clearance and in a porous layer are presented. Using the Morgan-Cameron approximation and an averaged inertia method the modified Reynolds equation for the curvilinear thrust bearing is given. The solution of this equation for the case of the squeeze film bearing is presented. As a result one obtains a formula expressing the pressure distribution. The example of a squeeze film between parallel disks is discussed in detail.
15
Content available remote Rheology of polymer melts and solutions
Walicka A., Walicki E.
International Journal of Applied Mechanics and Engineering
|
2010
|
Vol. 15, no 4
1253-1271
EN
In this work the authors consider some rheological models describing the fluid behaviours of polymer melts and solutions; these behaviours exhibit both viscoplastic and viscoelastic character. After presentation the bases of kinematics there were presented three dimensional models of pseudo-, visco-plastic and visco-elastic fluids of Rivlin-Ericksen and complex second grade fluids. Joining these models suitably one obtained the generalized models of second grade fluids. The connection between the above mentioned fluids is modelled in the following way: the constant coefficient of shear viscosity of a second grade fluid (Rivlin-Ericksen type) is replaced by a plastic viscosity taken from viscoplastic fluids. As an example the flow of generalized second grade fluid of the Shulman type in rectilinear channels is considered.
16
Content available remote Pressure drops in convergent flows of polymer melts
Walicka A., Walicki E.
International Journal of Applied Mechanics and Engineering
|
2010
|
Vol. 15, no 4
1273-1285
EN
Practical moulding processes of polymer melts involve geometrically complex dies. Such dies are usually tapered or streamlined as e.g. wedge or conical dies, to achieve maximum output rate under conditions of laminar flow. The models of generalized second grade fluids of a Shulman type are used and the results obtained are illustrated by examples of conical and wedge flows of power-law type and Bingham type fluids and the formulae for pressure drops were presented.
17
Content available remote Performance of the curvilinear thrust bearing lubricated by a pseudo-plastic fluid of Rotem-Shinnar
Walicka A., Walicki E.
International Journal of Applied Mechanics and Engineering
|
2010
|
Vol. 15, no 3
895-907
EN
In the paper the influence of inertia forces on the pressure distribution and load-carrying capacity of a thrust bearing with curvilinear working surfaces is discussed. The equations of motion of a pseudo-plastic fluid of Rotem-Shinnar, including inertia term of a circumferential flow, are used to derive the modified Reynolds equation. As a result of an analytical solution of the modified Reynolds equation the formulae for the bearing performance are obtained. Step and spherical bearings are considered as examples.
18
Content available remote Inertia effects in a curvilinear thrust hydrostatic bearing with a porous pad
Walicka A., Jurczak P., Walicki E.
International Journal of Applied Mechanics and Engineering
|
2010
|
Vol. 15, no 4
1227-1238
EN
The flow of a Newtonian lubricant in a clearance of a curvilinear thrust hydrostatic bearing with one porous wall is considered. The bearing is modelled by two curvilinear smooth surfaces and the porous wall is adhered to the curve non-porous surface. The flow in the bearing clearance is considered with inertia forces and the Navier-Stokes and Poisson equations are uncoupled by using the Morgan-Cameron approximation. The equations of motion are solved by an averaged inertia method. Step and spherical bearings are discussed as examples. It shown that the inertia effects influence the bearing performance considerably.
19
Content available remote Inertia effects in a curvilinear thrust hydrostatic bearing lubricated by a power-law lubricant
Walicka A., Jurczak P., Walicki E.
International Journal of Applied Mechanics and Engineering
|
2010
|
Vol. 15, no 4
1239-1251
EN
The flow of a power-law lubricant in a clearance of a curvilinear thrust hydrostatic bearing with impermeable walls is considered. The bearing is modelled by two curvilinear smooth surfaces. The lubricant flow in the bearing clearance is considered with inertia forces. The equations of motion for power-law fluid (similar to the boundary layer equations) are solved by an averaged inertia method. Step and spherical bearing are discussed as examples. It is shown that the inertia effects influence the bearing performance considerably.
20
Content available remote Couple-stress and surface roughness effects in curvilinear thrust bearings with a porous pad
Walicka A., Walicki E., Jurczak P., Michalski D.
International Journal of Applied Mechanics and Engineering
|
2008
|
Vol. 13, no 2
563-574
EN
On the basic of Christensen's stochastic model of rough surfaces, different forms of Reynolds equation with rotational inertia effect are obtained for various types of surface roughness pattern and for couple stress lubricant. As results one obtained the formulae expressing the mean film pressure distribution for externally pressurized bearings and for bearings with a squeeze film. An example of step bearing is considered.
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