Showing papers on "Shell balance published in 2011"

3D flow of a generalized Oldroyd-B fluid induced by a constant pressure gradient between two side walls perpendicular to a plate

Abstract: This paper deals with the 3D flow of a generalized Oldroyd-B fluid due to a constant pressure gradient between two side walls perpendicular to a plate. The fractional calculus approach is used to establish the constitutive relationship of the non-Newtonian fluid model. Exact analytic solutions for the velocity and stress fields, in terms of the Fox H-function, are established by means of the finite Fourier sine transform and the Laplace transform. Solutions similar to those for ordinary Oldroyd-B fluid as well as those for Maxwell and second-grade fluids are also obtained as limiting cases of the results presented. Furthermore, 3D figures for velocity and shear stress fields are presented for the first time for certain values of the parameters, and the associated transport characteristics are analyzed and discussed.

How Does Life Adapt to a Gravitational Environment? The Outline of the Terrestrial Gastropod Shell

Abstract: How do several characteristics adapt to gravity while mutually influencing each other? Our study addresses this issue by focusing on the terrestrial gastropod shell. The geometric relationship between the spire index () and outline (cylindricality) is theoretically estimated. When the shell grows isometrically, a high-spired shell becomes conical in shape and a low-spired shell becomes cylindrical in shape. A physical model shows that the lowest- and highest-spired shells are the most balanced. In addition, a cone shape is the most balanced for a low-spired shell, and a column shape is the most balanced for a high-spired shell. Spire index and cylindricality measured for freshwater gastropods follow the relationship estimated by the model, whereas those for terrestrial gastropods deviate from this relationship. This translates to a high shell being more cylindrical than a flat shell, except in the case of extremely high or low shells. This suggests that the shape of the most balanced shells (lowes...

Shear Thickening Oscillation in a Dilatant Fluid

Abstract: By introducing a state variable, we construct a phenomenological fluid dynamical model of a dilatant fluid, i.e., a dense mixture of fluid and granules that shows severe shear thickening. We demonstrate that the fluid shows shear thickening oscillation, namely, the fluid flow oscillates owning to the coupling between the fluid dynamics and the internal dynamics of state. We also demonstrate that the jamming leads to a peculiar response to an external impact on the fluid.

Effect of Hydrostatic Pressure on Input Power Flow in Submerged Ring-stiffened Cylindrical Shells

Abstract: The input power flow for an infinite ring-stiffened cylindrical shell submerged in fluid induced by a cosine harmonic circumferential line force under conditions of a uniform external hydrostatic pressure field is investigated in this paperThe motion of the shell and the pressure field of the external fluid are described by the Flugge's thin shell theory and the Helmholtz equation respectivelyThe effect of the external pressure field is modeled by including static prestress terms in the shell equations of motionThe effects of hydrostatic pressure on the input power flow are examinedThe results show that the external pressure shifts the curves of input power flow to left along the frequency axisThe effect is more obvious with higher external pressure and circumferential modeIt will give some guidelines for vibration and noise control of this kind of shell

Applied & computational fluid mechanics

Abstract: 1. Dimensions, Units, and Properties. 2. Fluid Statics. 3. Fluid Dynamics. 4. Differential Equations of Fluid Motion and CFD. 5. Pipe Flow. 6. Lift and Drag. 7. Rotating Machinery. 8. Applications. 9. Fluid Measurement Devices. Appendices. Index.

Critical Fluid Velocity of Fluid-conveying Cantilevered Cylindrical Shells with Intermediate Support

Abstract: The critical fluid velocity of cantilevered cylindrical shells subjected to internal fluid flow is investigated in this study. The fluid-structure interaction is considered in the analysis. The cantilevered cylindrical shell is supported intermediately at an arbitrary axial position. The intermediate support is simulated by two types of artificial springs: translational and rotational spring. It is assumed that the artificial springs are placed continuously and uniformly on the middle surface of an intermediate support along the circumferential direction. The steady flow of fluid is described by the classical potential flow theory. The motion of shell is represented by the first order shear deformation theory (FSDT) to account for rotary inertia and transverse shear strains. The effect of internal fluid can be considered by imposing a relation between the fluid pressure and the radial displacement of the structure at the interface. Numerical examples are presented and compared with existing results.

Shell Balance Approach for One-Dimensional Biofluid Transport

Abstract: Analysis methods in Chap. 9 were based on a macroscopic approach to bioheat transport, in which the system of interest was assumed to have a relatively uniform temperature. The temperature might change with time, but spatial variations within the system were assumed to be negligible or unimportant. In this chapter we will turn our interest to problems where there is an important spatial gradient in temperature. The spatial temperature gradient will cause a conduction heat flux in accordance with Fourier’s law (2.9). Here we will restrict the scope of problems to those that are dimensional or nearly one-dimensional. Our analysis in each of these problems will begin by applying conservation of energy on an infinitesimally small portion of the system, known as a shell. A feature which distinguishes this approach from the more general approach to be applied in Chap. 11 is that the shells used in this chapter will shrink only in one dimension, so they might include a portion of the system boundary, while the shells used in the general approach shrink around an interior point in the system and do not include any portion of the system boundary. Consequently, energy that enters the system through the portion of the shell that includes the system boundary will be treated in this chapter as a term in the conservation equation rather than as a boundary condition. In reality, heat that enters through the system boundary often enters in a direction that is perpendicular to the assumed direction of energy flow. Although energy flow is not truly one-dimensional in such cases, the shell balance approach allows us to obtain realistic approximate solutions in which a more rigorous multidimensional approach would greatly increase the complexity but add little to the understanding or accuracy of the solution.