Topic
Static pressure
About: Static pressure is a research topic. Over the lifetime, 9770 publications have been published within this topic receiving 82614 citations.
Papers published on a yearly basis
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Papers
TL;DR: In this paper, the melting point of iron and iron-oxygen compounds at static pressure of up to 3.3 Mbar was estimated for the inner core boundary of the Earth's core.
Abstract: THE temperature distribution in the Earth's core places important constraints on the Earth's internal heat budget and on models of the geodynamo. The solid inner core crystallizes from a liquid outer core, consisting mainly of iron alloyed with a lighter element, at a depth of about 5,100 km (corresponding to a pressure of about 3.3 Mbar). Thus, the most reliable means of determining the temperature gradient in the core is to estimate the melting temperature of iron and iron-rich compounds at the pressure of the inner core boundary. Current estimates range from about 4,000 to 8,000 K; but these estimates, obtained from shock compression1–3, theory (discussed in ref. 4) and extrapolation of static pressure data2,3,5, are poorly constrained. Here I present melting-point measurements on iron and iron–oxygen compounds at static pressures of up to Mbar. Extrapolation of these results to 3.3 Mbar yields a temperature at the inner-core boundary of 4,850±200 K. A weak change in optical absorption observed above 2,000 K may correspond to the solid–solid phase transition found in shock experiments at 2 Mbar (ref. 1).
632 citations
TL;DR: In this article, the von Neumann-Richtmyer artificial viscosity was employed to avoid shock discontinuities, and the solutions were carried from two thousand atmospheres to less than one-tenth atmospheres peak overpressure.
Abstract: The strong‐shock, point‐source solution and spherical isothermal distributions were used as initial conditions for a numerical integration of the differential equations of gas motion in Lagrangean form. The von Neumann‐Richtmyer artificial viscosity was employed to avoid shock discontinuities. The solutions were carried from two thousand atmospheres to less than one‐tenth atmospheres peak overpressure. Results include overpressure, density, particle velocity, and position as functions of time and space. The dynamic pressure, the positive and negative impulses of both dynamic pressure and static overpressure, positive and negative durations of pressure and velocity, and shock values of all quantities are also described for various times and radial distances. Analytical approximations to the numerical results are provided.
555 citations
TL;DR: In this paper, an experimental investigation of the flow around and pressure forces on fixed (non-vibrating) rectangular cylinders at angles of attack 0°-90° was conducted.
509 citations
TL;DR: In this article, a simple method of determining local turbulent skin friction on a smooth surface has been developed which utilises a round pitot tube resting on the surface, assuming the existence of a region near the surface in which conditions are functions only of the skin friction, the relevant physical constants of the fluid and a suitable length, a universal non-dimensional relation is obtained for the difference between the total pressure recorded by the tube and the static pressure at the wall, in terms of skin friction.
Abstract: A simple method of determining local turbulent skin friction on a smooth surface has been developed which utilises a round pitot tube resting on the surface. Assuming the existence of a region near the surface in which conditions are functions only of the skin friction, the relevant physical constants of the fluid and a suitable length, a universal non-dimensional relation is obtained for the difference between the total pressure recorded by the tube and the static pressure at the wall, in terms of the skin friction. This relation, on this assumption, is independent of the pressure gradient. The truth and form of the relation were first established, to a considerable degree of accuracy, in a pipe using four geometrically similar round pitot tubes—the diameter being taken as representative length. These four pitot tubes were then used to determine the local skin friction coefficient at three stations on a wind tunnel wall, under varying conditions of pressure gradient. At each station, within the limits of experimental accuracy, the deduced skin friction coefficient was found to be the same for each pitot tube, thus confirming the basic assumption and leaving little doubt as to the correctness of the skin friction so found. Pitot traverses were then made in the pipe and in the boundary layer on the wind tunnel wall. The results were plotted in two non-dimensional forms on the basis already suggested and they fell close together in a region whose outer limit represented the breakdown of the basic assumption, but close to the wall the results spread out, due to the unknown displacement of the effective centre of a pitot tube near a wall. This again provides further evidence of the existence of a region of local dynamical similarity and of the correctness of the skin friction deduced from measurements with round pitot tubes on the wind tunnel wall. The extent of the region in which the local dynamical similarity may be expected to hold appears to vary from about 1/5 to 1/20 of the boundary-layer thickness for conditions remote from, and close to, separation respectively.
455 citations
TL;DR: In this article, an attempt has been made to form a qualitative correlation between the nozzle shape and the issuing jet shape, which is best achieved by a sudden, smooth contraction of the flow area from the supply line to the desired nozzle diameter.
409 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 6 |
| 2024 | 18 |
| 2023 | 42 |
| 2022 | 53 |
| 2021 | 178 |
| 2020 | 281 |