Calibration of a miniature permanent magnet flowmeter probe and its application to velocity measurements in liquid sodium
| Autor: | J.U Knebel, L Krebs |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Fluid Flow and Transfer Processes
Jet (fluid) Materials science Turbulence Mechanical Engineering General Chemical Engineering Prandtl number Aerospace Engineering Reynolds number Mechanics Flow measurement Magnetic field Physics::Fluid Dynamics symbols.namesake Nuclear magnetic resonance Nuclear Energy and Engineering Flow velocity Magnet symbols |
| Zdroj: | Experimental Thermal and Fluid Science. 8:135-148 |
| ISSN: | 0894-1777 |
| DOI: | 10.1016/0894-1777(94)90041-8 |
| Popis: | The calibration of a miniature permanent magnet flowmeter probe (MPMF probe) for velocity measurements in liquid metals, such as sodium, and its use in performing velocity measurements are discussed. Velocity measurements were made in a vertical axisymmetric and nonisothermal jet flow, the jet having an initial densimetric Froude number of 521. The jet discharged into a weakly turbulent, coflowing ambient with a Reynolds number of 14 × 10 3 . The physical principle of the MPMF probe is the induction law. The electric signals of the probe are proportional to the flow velocity if an electrically conducting fluid passes a constant magnetic field perpendicular to the flow direction. The magnetic field is produced by a miniature permanent magnet inside the probe. Furthermore, a thermoelectric or Seebeck potential influences the probe signals if a temperature field is superimposed on the velocity field. In addition, in the presence of temperature gradients, inhomogeneities in the electrode wires of the probe can generate potentials that are an important source of error. In this paper, a new temperature compensation method of the probe signals is demonstrated that can eliminate these influences. The calibration method and two different velocity measurement methods are described in detail. The sensitivity of the probe is determined. Finally, the velocity data for the sodium jet are compared with data from the literature that are obtained in fluids of common Prandtl number, such as water or gases. |
| Databáze: | OpenAIRE |
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