in this paper, the static characteristics of two-lobe, three-lobe and four-lobe noncircular gas journal bearing systems are studied in detail. the reynold’s equation governing the noncircular gas bearing systems are analyzed by using radial basis functions (rbf). the solutions are obtained numerically by solving systems of algebraic equations. the equilibrium position of the rotor is obtaine...

This paper presents the effect of preload on static and dynamic performance characteristics of several gas-lubricated noncircular journal bearing configurations. The linearized system approach using finite element method is used to obtain both steady state and dynamic characteristics. The results of the investigation shows that preload has a significant effect on frictional power loss and the ...

This paper presents the effect of preload on nonlinear dynamic behavior of a rigid rotor supported by two-lobe aerodynamic noncircular journal bearing. A finite element method is employed to solve the Reynolds equation in static and dynamical states and the dynamical equations are solved using Runge-Kutta method. To analyze the behavior of the rotor center in the horizontal and vertical directi...

Abstract: Thin-walled integrated flexible support structures are the major trend in the development of current rolling bearing technology. A thin-walled, integrated, squirrel-cage flexible support roller bearing, quasi-dynamic iterative finite element analysis (FEA) model is established in this paper. The FEA model is used to calculate the structural deformation of the thin-wall rings and suppo...

this paper presents the application of the generalized differential quadrature (gdq) method for the hydrodynamic analysis of circular and noncircular, two lobe and three lobe, journal bearings. gdq is a simple, efficient, high-order numerical technique and it uses the information on all grid points to approach the derivatives of the unknown function. the effectiveness of the solution technique ...

Designers have tried for many years to apply noncircular gears in automatic machines and instruments. The obstacle was the lack of effective methods of generation of noncircular gears similar to those applied for the generation of circular gears. However, researchers have continued the investigation of application of noncircular gears – see the earlier works by Burmester (Burmester, 1888), Golb...

1. Asymmetric Volume Coils Asymmetric, noncircular volume coils are required in situations where the available access bore is noncircular in cross section, such as for table-top applications [1] or where the gradient bore is noncircular [2]. They consist of ladder network resonators such as the birdcage [3] or TEM [4] coil that have been modified by placing their rungs on a cylindrical surface ...

In order to perform fan-beam reconstruction using projection data collected from a noncircular scanning locus, existing noncircular fan-beam formulas require a derivative of the scanning locus with respect to the rotation angle. A derivative-free noncircular fan-beam reconstruction formula that is based on a geometrical explanation of the circular equispatial fan-beam reconstruction formula is ...

The strictly linear quaternion valued affine projection algorithm (QAPA) and its widely linear counterpart (WLQAPA) are introduced, in order to provide fast converging stochastic gradient learning in the quaternion domain, for the processing of both second order circular (proper) and second order noncircular (improper) signals. This is achieved based on the recent advances in augmented quaterni...

After providing an extension of the Slepian–Bangs formula for general noncircular complex Gaussian distributions, this paper focuses on the stochastic Cramér–Rao bound (CRB) on direction-of-arrival (DOA) estimation accuracy for noncircular sources. We derive an explicit expression of the CRB for DOA parameters alone in the case of noncircular complex Gaussian sources by two different methods. O...