Pressure distributed load

Turbomaehinery bearing systems are normally designed for radial loads eorresponding to the weight of the rotor. Non-uniform pressure distribution around the wheel(s) of a turbomaehine may also eontri-bute to the magnitude of gas dynamie radial load, oeeasionally ealled side load. The sourees of gas dynamie radial loads on the eom-pressor wheel are different from those at the expander wheel. 

On the expander side, the expander wheel is surrounded by the nozzle vanes. The nozzle vanes, in turn, reeeive gas from a toroidal spaee that is eonneeted to tlie expander inlet piping. Any non-uniformity in the torus spaee and/or in the nozzle vane design may result in a non-uniform pressure distribution around the expander wheel. Non-uniform gas pressure around the expander wheel will result in a non-uniform load and, henee, produee a gas dynamie radial load on the bearing. In the expander ease, however, the nozzle throat flow resistanee is mueh larger than the easing peripheral pressure nonuniformity. The latter aets as a buffer making the expander wheel eireumferential pressure variations smaller than those of the eompressor side. This smaller pressure variation produees mueh less radial load when eompared to that of the eompressor side. 

An object struck by a blast wave experiences a loading. This loading has two aspects. First, the incident wave induces a transient pressure distribution over the... 

In summary, an object s blast loading has two components. The first is a transient pressure distribution induced by the overpressure of the blast wave. This component of blast loading is determined primarily by reflection and lateral rarefaction of the reflected overpressure. The height and duration of reflected overpressure are determined by the peak side-on overpressure of the blast wave and the lateral dimensions of the object, respectively. The Blast loading of objects with substantial... 

In an efficient and economical steam system, this so-called flash steam will be utilized on any load that can make use of low-pressure steam. Sometimes it can be simply piped into a low-pressure distribution main for general use. The ideal is to have a greater demand for low-pressure steam at all times than the available supply of flash steam. Only as a last resort should flash steam be vented to atmosphere and lost. 

The velocity analysis is of great important for a lubrication theory, which will lay the foundation for further processes, to obtain the flux, the pressure distribution, the load and the friction, etc. As shown before, however, the present model requires a complex procedure to achieve the results. Thus, it can be regarded as a more purely scientihc one," i.e., there is a long way to the success of predictive ability. For a practical purpose, from an engineering point of view, some simplifications should be conducted in an attempt to get the parameters of interest. 

Let us compare the magnitude of the van der Waals pressure with that of air bearing pressure. In Section 3.2, we have shown the numerical solution of gas pressure distribution for a two-rail slider and a O t pe slider. By simply summing up the contributions of gas pressure and van der Waals pressure and integrating over the whole slider surface area, the total dimensionless load carrying capacity becomes... 

In numerical analysis, both functions of normal surface deformation and pressure distribution have to be discretized in a space domain over U grid points for a line load, or grid points for two-dimensional distributed load. As an example, the deformation for line loading can be rewritten in discrete form as follows ... 

The influence coefficient (IC) A( has been interpreted physically as the deformation at pointx due to unit point load acting on Xy. For the distributed load, Aj can be obtained through calculating the deformation at Xj, caused by the pressure distributed over a small area around the positionxy ... 

When the plane moves at 0.1 mm/s and under a normal load of 38.29 N, the numerical mixed lubrication model yields the solutions of film thickness and pressure distribution shown in Fig. 11 where the profiles are taken along the central lines in the x and y directions, respectively. Corresponding results from dry contact analyses are given in the same hgure for comparison. Excellent agreements observed... 

In summary, the height distribution of surface roughness, characterized by the skewness and kurtosis, may present a significant influence on certain performances of mixed lubrication, such as the real contact area, the load carried by asperities, and pressure distribution, while the average film thickness and surface temperature are relatively unaffected. 

Take into consideration a lubricated system composed of a smooth steel ball and a rigid plane. As the entraining speed decreases under a fixed load, the changes of film thickness, pressure distribution, and contact area ratio with speed are presented in Figs. 29 and 30. 

Figure 10. Pressure distribution between beveled diamond culets under two different loads. The central flat region, where the sample is confined, is 10 pm in diameter while the rest of the culet is immersed in the gasket material. The lower picture schematically shows the diamond culets corresponding to the two pressure profiles. The shaded area indicates the extent of the diamond deformation at the highest load. (Adapted from Ref. 149.)...

The influence of this pressure distribution on the displacements in a neighboring area on the same boundary surface can be analyzed as shown in Fig. 2.8. Let M be an arbitrary point outside the circular area (Fig. 2.8(a)) or inside the circular area (Fig. 2.8(b)) with a distance r from the center of the circular area. A small element within the loaded zone is chosen as s d/5 ds, where s is the distance between this element and M. From the solution of lz for a point force on a semiinfinite solid, the increment of the vertical displacement at location M under the influence of this element force would be... 

The normal load on the nitrogen net meets the specifications of the net with reasonable safety margins, but under special oc-cations very high spot loads may occur. In such a case the pressure at some load points may drop below safe limits and cause the plants to trip out. Hence, the maximum spot load capacity as well as the pressure distribution under such a load are important for the safety of the plant as a system of interconnected units. This kind of information may be easily obtained by simulation, as outlined in this paper. 

Point Load—The general solution of the pressure-distribution in a medium, generated by a point load applied to a packing of unlimited. depth and extent, is due to Boussinesq (1876, 1885)... 

Distributed Load—If the pressure is distributed over a beam of length 2b and unit width, as shown in Figure 43, with a uniform loading of P0 per unit length, then the stress intensity pz at any point (x, z) is given by either of the equations ... 

Pressure Distribution Due to a Loaded Disc—We may solve the pressure distribution along the axis of a loaded disc from the following equation. If P0 denotes the pressure intensity on the disc and D is the diameter of the disc, then... 

Kogler and Scheidigs results for a 63 cm diameter disc load are shown in Figure 46. The pressure distribution is characteristic and contours of constant pressure intensity may be termed Boussinesq pressure bulbs. It will be noted from the figure that there is an upper region where no... 

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