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Showing papers on "Volume of fluid method published in 1983"


Journal ArticleDOI
TL;DR: In this article, the onset of steady natural convection in a rotating cylindrical volume of fluid completely bounded by rigid surfaces is examined for moderate Taylor numbers (Ta≤2×106) and aspect ratios (A≤ 2).
Abstract: The onset of steady natural convection in a rotating cylindrical volume of fluid completely bounded by rigid surfaces is examined for moderate Taylor numbers (Ta≤2×106) and aspect ratios (A≤2). The critical Rayleigh number for three dimensional disturbances is found to be lower than that for the radially unbounded problem by up to a factor of six. The thermal boundary condition on the lateral walls is shown to have a greater effect here than in the nonrotating case.

49 citations


Patent
23 May 1983
TL;DR: In this paper, the volume of blood pumped by an artificial ventricle or ventricular assist device is extracorporeally monitored as a function of the volume used to drive the ventricles.
Abstract: The volume of blood pumped by an artificial ventricle or ventricular assist device is extracorporeally monitored as a function of the volume of fluid used to drive the ventricle. The ventricle is divided into two chambers by a flexible diaphragm. Fluid is alternately supplied to one chamber during systole and then removed from that chamber during diastole. In the preferred embodiment, during systole the rate of fluid flow is sensed by establishing a differential pressure between two points in the fluid's flow path. The differential pressure is converted to a proportional voltage which may be integrated to provide the desired volume over a given time interval, which corresponds to the cardiac output within ±5-10%.

20 citations


Patent
18 Jul 1983
TL;DR: In this article, a method of determining the net volume of water and oil in a flow stream, including the steps of collecting the fluid in a vessel providing a quiescent zone, venting pressure from the vessel to permit at least a portion of dissolved gas to flush from the fluid, repressuring the fluid within the vessel, and passing the fluid from a vessel while subjected to a superatmospheric pressure through a sonic apparatus having a sonic path disposed at an angle to the flow stream to measure the upstream and downstream speed of sound transmission of the fluid.
Abstract: A method of determining the net volume of water and oil in a flow stream, including the steps of collecting the fluid in a vessel providing a quiescent zone, venting pressure from the vessel to permit at least a portion of dissolved gas to flush from the fluid, repressuring the fluid within the vessel to a superatmospheric pressure to force any remaining entrained gas bubbles back into solution, passing the fluid from the vessel while subjected to a superatmospheric pressure through a sonic apparatus having a sonic path disposed at an angle to the flow stream to measure the upstream and downstream speed of sound transmission of the fluid, calculating from the difference in the upstream and downstream speeds of sound transmission the volume of fluid flow and from the summation of the speeds of sound transmission the fluid composition, and from these calculations the net volume of oil and water flow.

15 citations


Journal ArticleDOI
TL;DR: In this article, the authors used the asymptotic method of Vishik and Lyusternik [5] and Chernous' ko [6] to solve the problem of translational vibrations of an axisymmetric body in a bounded volume of viscous fluid.
Abstract: The problem of the vibrations of a body in a bounded volume of viscous fluid has been studied on a number of occasions [1–4]. The main attention has been devoted to determining the hydrodynamic characteristics of elements in the form of rods. Analytic solution of the problem is possible only in the simplest cases [2]. In the present paper, in which large Reynolds numbers are considered, the asymptotic method of Vishik and Lyusternik [5] and Chernous' ko [6] is used to consider the general problem of translational vibrations of an axisymmetric body in an axisymmetric volume of fluid. Equations of motion of the body and expressions for the coefficients due to the viscosity of the fluid are obtained. It is shown that in the first approximation these coefficients differ only by a constant factor and are completely determined if the solution to the problem for an ideal fluid is known. Examples are given of the determination of the “viscous” added mass and the damping coefficient for some bodies and cavities. In the case of an ideal fluid, general estimates are obtained for the added mass and also for the influence of nonlinearity. Ritz's method is used to solve the problem of longitudinal vibrations of an ellipsoid of revolution in a circular cylinder. The hydrodynamic coefficients have been determined numerically on a computer. The theoretical results agree well with the results of experimental investigations.

2 citations


Patent
30 Apr 1983
TL;DR: In this paper, the authors proposed to prevent reduction of fluid energy by providing the flow tube with a part whose sectional area is twice as large as that of other parts and concentrating the pressure due to gravity at the tube.
Abstract: PURPOSE:To prevent reduction of fluid energy by providing the flow tube with a part whose sectional area is twice as large as that of other parts and concentrating the pressure due to gravity at the flow tube. CONSTITUTION:The fluid is flowed in the direction perpendicular to the earth by providing the flow tube with a part whose sectional area is larger than other parts. In this part 2 the volume of fluid becomes large to cause increased weight, and the pressure due to the gravity acts directly on the part 3 in adjacency. Because slopes 9.10 are very mild, water pressure due to gravity acts on the slopes 9.10 normally. Accordingly fluid with a large energy flows out of the line 3 and the energy is bred. Thus reduction of the fluid energy is prevented.

2 citations


Patent
14 Oct 1983
TL;DR: In this paper, an accumulator device is designed in such a way that the additional volume of fluid enclosed in the displacement vessel produced due to thermal expansion is forced through the pressure valve into the accumulator and that further fluid is drawn in when the volume of liquid contracts.
Abstract: The device comprises at least one displacement vessel (1), with intake (5) and pressure non-return valve (6) and an accumulator device (8). The entire unit is designed in such a way that the additional volume of fluid (2) enclosed in the displacement vessel produced due to thermal expansion is forced through the pressure valve into the accumulator and that further fluid is drawn in when the volume of fluid contracts. This results in a fluid delivery acting in the same direction brought about by temperature fluctuation. Furthermore, additional devices can be provided for producing temperature fluctuations.

1 citations