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Total pressure

About: Total pressure is a research topic. Over the lifetime, 5199 publications have been published within this topic receiving 66658 citations.


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Journal ArticleDOI
TL;DR: In this article, a system for fast-response probe measurements in turbomachine flows has been developed and tested with various in-house built probes accommodating up to four piezoresistive pressure transducers.
Abstract: A system for fast-response probe measurements in turbomachine flows has been developed and tested. The system has been designed for 40 kHz bandwidth and used with various in-house built probes accommodating up to four piezoresistive pressure transducers. The present generation of probes works accurately up to several bar pressure and 120°C temperature. The probes were found to be quite robust. The use of a miniature pressure transducer placed in the head of a probe showed that a precise packaging technique and a careful compensation of errors can considerably improve the accuracy of the pressure measurement. Methods for aerodynamic probe calibration and off-line data evaluation are briefly presented. These aimed, e.g., in the case of a four-hole probe, at measuring the velocity fluctuations as characterized by yaw, pitch, total pressure, and static pressure and at deriving mean values and spectral or turbulence parameters. Applications of the measuring system to turbomachinery flow in a radial compressor and to a turbulent pipe flow demonstrate the performance of the measuring system.

36 citations

Journal ArticleDOI
TL;DR: In this article, a theoretical model on oxygen transport at the surface of liquid metals has been validated by dynamic surface tension measurements performed on liquid tin as test metal The oxygen contamination conditions have been obtained at different oxygen partial pressures under low total pressure conditions (Knudsen regime), confirming that an oxide removal regime occurs under an oxygen partial pressure much higher than the equilibrium one (the effective Oxidation Pressure).

36 citations

Journal ArticleDOI
TL;DR: In this paper, the absorption spectrum has been generated for H2O, CO2, and CO at total pressures varying from 0.1 to 50 atm using the HITEMP 2010 spectroscopic database.
Abstract: The absorption spectrum has been generated for H2O, CO2, and CO at total pressures varying from 0.1 to 50 atm using the HITEMP 2010 spectroscopic database. From these spectra the absorption line blackbody distribution function (ALBDF) has been calculated at variable total pressure in order to understand the importance of accounting for pressure changes on this parameter. The ALBDF is used in the SLW solution method to the radiative transfer equation. ALBDF data for H2O, CO2, and CO are presented, revealing a shift in the ALBDF to lower values as total pressure increases. This shift is weaker at high temperature. The shift due to increase in mole fraction of H2O and CO2 was shown to be modest, and similar at different pressures. The ALBDF was shown to become less smooth as pressure increases. Total emissivity calculations are presented for variable total pressure, and it is seen that pressure changes account for a significant change in total emissivity. Total radiative flux and radiative flux divergence were calculated from line-by-line spectral integrations for one-dimensional layers of constant length and constant mass cases, showing that total pressure changes result in a significant impact on radiative transfer in a layer of gas. Radiative flux exiting a layer of gas can change by more than a factor of four over the pressure range investigated when the pressure change is the only variable considered.

35 citations

Journal ArticleDOI
TL;DR: In this article, the authors deduced a general formula for pressure of degenerate and relativistic electrons, P-e, which is suitable for superhigh magnetic fields, and discussed the quantization of Landau levels of electrons, and considered the quantum electrodynamic (QED) effects on the equations of states (EOSs) for different matter systems.
Abstract: Based on our previous work, we deduce a general formula for pressure of degenerate and relativistic electrons, P-e, which is suitable for superhigh magnetic fields, discuss the quantization of Landau levels of electrons, and consider the quantum electrodynamic (QED) effects on the equations of states (EOSs) for different matter systems. The main conclusions are as follows: P-e is related to the magnetic field B, matter density rho, and electron fraction Y-e; the stronger the magnetic field, the higher the electron pressure becomes; the high electron pressure could be caused by high Fermi energy of electrons in a superhigh magnetic field; compared with a common radio pulsar, a magnetar could be a more compact oblate spheroid-like deformed neutron star (NS) due to the anisotropic total pressure; and an increase in the maximum mass of a magnetar is expected because of the positive contribution of the magnetic field energy to the EOS of the star.

35 citations

Patent
23 May 1996
TL;DR: In this article, a high temperature gas flow sensing element is disclosed having a housing with similar internal dimensions as the fluid conduit, whether round or rectangular, and an interior flow conditioner is affixed at the inlet of the flow element.
Abstract: A high temperature gas flow sensing element is disclosed having a housing with similar internal dimensions as the fluid conduit, whether round or rectangular. An interior flow conditioner is affixed at the inlet of the flow element. A total pressure sensing pitot tube array is affixed traversing the interior cross sectional area of flow element for sensing the total pressure of fluid flowing into the flow element, and a static pressure sensing pitot tube array is also affixed traversing the interior cross sectional area of the flow element for sensing the average static pressure within the flow element. The pitot tubes and pressure sensing tubes are affixed at four places, two shell penetrations and two places at the manifolds, regardless of manifold design or the element shape. To prevent material stress and fatigue and leakage that can result from the different expansion rates of differing materials under high gradient temperature cycling, a high temperature packing, such as a ribbon packing or packing ring made of pliable material resistant to high temperatures, is used in place of the ferrule portion of a compression nut and fitting arrangement. Exterior first and second instrument taps are provide for connection of each array respectively to a differential pressure instrument for indicating flow rate and/or transmitting a flow rate signal. Further, exterior array access ports are provided to permit cleaning of each pitot arrays should they become plugged with particulates.

35 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202316
202225
2021127
2020147
2019153
2018128