Showing papers on "Shell balance published in 1977"
TL;DR: In this paper, the thermal shield in reactor internals and other system components to avoid detrimental flow-induced vibrations is modeled as two coaxial shells separated by a viscous fluid, from which the natural frequency, mode shape, and modal damping ratio of coupled modes can be calculated.
Abstract: This study was motivated by the need to design the thermal shield in reactor internals and other system components to avoid detrimental flow‐induced vibrations. The system component is modeled as two coaxial shells separated by a viscous fluid. In the analysis, Flugge’s shell equations of motion and linearized Navier–Stokes equation for viscous fluid are employed. First, a traveling‐wave‐type solution is taken for shells and fluid. Then, from the interface conditions between the shells and fluid, the solution for the fluid medium is expressed in terms of shell displacements. Finally, using the shell equations of motion gives the frequency equation, from which the natural frequency, mode shape, and modal damping ratio of coupled modes can be calculated. The analytical results show a fairly good qualitative agreement with the published experimental data. With the presented analysis and results, the frequency and damping characteristics can be analyzed and design parameters can be related to frequency and damping.
25 citations
TL;DR: In this paper, it was shown that the meridional components of velocity can be derived from a stream-function, the trajectories of the fluid particles being spirals wound around torus-shaped surfaces.
Abstract: fluid which is characterized by a general density-pressure relation ,u(p). It is shown that the meridional components of velocity can be derived from a stream-function, the trajectories of the fluid particles being spirals wound around torus-shaped surfaces. The moment of the velocity, and another dynamical variable, are conserved for fluid particles along their motion. However, the relativistic angular-momentum-density is convectively conserved only in a fluid in which the velocity of sound equals the velocity of light. We evaluate the total angular momentum L and the total energy E of a spherical vortex in such a fluid, based on a solution given previously. Putting L = h and E = Mc2, where m denotes the mass of the neutron, and letting the maximum value of the flow in the vortex equal c, we get a value of 1.2 x 10-13 cm for the radius of the vortex. 1. INTROD UCTION In nonrelativistic hydrodynamics, the assumption of incompressibility, which is made for mathematical convenience, provides a useful approximation to a wide class of naturally occurring flows of real fluids in which the effects of incompressibility are small. The notion of incompressibility is, however, alien to relativistic hydrodynamics because of the associated infinite value of the velocity of sound. The question therefore arises whether in relativistic hydrodynamics there exists a model which provides mathematical simplification in the manner in which the model of an incompressible fluid does in the non-relativistic case. Such a model was found to be (Pekeris I976) a fluid in which the velocity of sound u8 exactly equals the velocity of light c. The discussion was based on an assumed linear relationship between the density t and the pressure p
1 citations