Mass eccentricity

Note 2 The mass eccentricity associated with balance grade Gl.O is very small (for example, 0.0001 in. maximum for operation at 3800 RPM). Therefore, the balance quality may not be verifiable if the rotor is disturbed from its position on the balancing stand or disassembled and reassembled. It is normally possible, however, to perform a residual unbalance check to verify the accuracy of the balancing stand. 

With modern balancing machines, it is feasible to balance components mounted on their arbors to U = 4 Nh (nominally equivalent to ISO grade G1), or even lower depending upon the weight of the assembly, and to verify the unbalance of the assembly with a residual unbalance check. However, the mass eccentricity, e, associated with unbalance less than U = 8W/n (nominally equivalent to ISO grade G2.5) is so small (e.g. U = 4Wh gives e = 0,000 070 in for an assembly intended to run at 3600 r/min) that it cannot be maintained if the assembly is dismantled and remade. Balance grades below G2.5 (8W/n) are, therefore, not repeatable for components. 

The mass eccentricity associated with balance grade G1 is very small for example 2,5 pm (0,000 10 in) maximum for operation at 3 800 r/min. This has two consequences ... 

The optimum design of steel reinforced concrete 3D frames is formulated in this study on the basis of the FEMA-310 (1998) recommendation where the torsional response demands is to be reduced during a seismic event and thus implicitly enhance the seismic resistance of the structure. In this study, based on the work of Bertero (1995), response demands are reduced by minimizing the mass eccentricity, which is defined as the distance between the mass and the rigidity centers in each storey. 

L8. Levy, S., Polomik, E. E., Swan, C. L., and McKinney, A. W., Eccentric rod burnout at 1000 psia with net steam generation, Intern. J. Heat Mass Trans. 5 (July 1962). 

Noordsij and Rotte (N10) studied mass transfer at a vibrating sphere. The oscillating motion was achieved by means of an attached rod, held by a spring against an eccentric wheel. The results, showing considerable scatter, are represented approximately by a Pe1/2 dependence, with an additive constant term accounting for pure diffusion. 

Even stronger constraints are potentially available from the high-mass X-ray binary Vela X-l. This source contains a 20 M0 star, and radial velocity variations from the star have been measured as well as periodic timing variations from X-ray pulses. The orbital period is 8.96 days and the eccentricity of... 

Limiting Nusselt numbers for laminar flow in annuli have been calculated by Dwyer [Nucl, Sci, Eng, 17,336 (1963)]. In addition, theoretical analyses of laminar-flow heat transfer in concentric and eccentric annuh have been published by Reynolds, Lundberg, and McCuen [Int, J, Heat Mass Transfer, 6, 483, 495 (1963)]. Lee [Int, J, Heat Mass Transfer, 11,509 (1968)] presented an analysis of turbulent heat transfer in entrance regions of concentric annuh. FuUy developed local Nusselt numbers were generally attained within a region of 30 equivalent diameters for 0.1 < Npr < 30,10 < < 2 x 10, 1.01 <... 

The underflow of the cyclone 7 is withdrawn by an eccentric worm pump 8 and delivered to a belt filter press 9 yielding a highly dewatered cake and a filtrate consisting essentially of water but loaded with small concentrations of sulfuric acid, furfural, and by-products. This filtrate is recycled to tank 1 for preparing the feed stock slurry. Due to this scheme, most of the sulfuric acid is recovered and reutilized, the only loss being the quantity contained in the cake. This loss is replaced in tank 1. Analogously, the water leaving the system with the cyclone vapor and the cake is also replenished in tank 1 so that the overall mass balance is satisfied. 

Velocity gradients within bins should also be minimized (60). To achieve this, the hopper must be significantly steeper than the mass flow limit, which may result in an impractically tall bin. Alternate approaches include the use of inserts. However, these must be properly designed and positioned to be effective. Asymmetric bins and hoppers should be avoided, and symmetrical ones should be used whenever possible. Eccentric hoppers should be avoided due to their inherently large velocity gradients. 

Equations (70) may be studied separately. The first equation says that the stationary solutions lie at the extrema of the function Ries with respect to the variables ai. These extrema depend only on the ratio of the masses of the two planets and on the eccentricities (constants in the stationary solution). The factor Gm 2 does not affect the results. 

Figure 8. Loci of the stationary corotation solutions of the 2/1 resonance for several mass ratios m2/mi. Top figures correspond to the symmetric solutions of the two left-hand side plots in Figure 6. The points corresponding to two early determinations of the elements of Gliese 876 are shown in one of these plots. The bottom figure corresponds to the asymmetric solutions of the two right-hand side plots in Figure 6. The line across these curves shows the values of the eccentricities for which 0.63(1 + ei) = (1 — e2). In all panels, the thick line shows the boundary between the domains of symmetric and asymmetric solutions.

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