science-review.ru
Scientific journal
Scientific Review. Technical science
ISSN 2500-0799
ПИ №ФС77-57440
ISSN 2500-0799
ПИ №ФС77-57440
EFFECT OF STABILIZING DEVICES ON PRESSURE PULSATIONS IN CONICAL DIFFUSER OF A DRAFT TUBE MODEL
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The aim of the work was an experimental study of influence of stabilizing devices on amplitude-frequency characteristics of pressure fluctuations in conical diffuser of draft tube with a divergent angle of 8.3 deg. The studies were carried out in the range of Reynolds numbers Re ≈ 2.5∙103 - 22∙103 with the swirl number S = 1.64. Velocity profiles were obtained using an LDA system fordifferent type of stabilizing devices installed in the inlet conical diffuser. To obtain the energy spectra of pressure fluctuations sophisticated acoustic sensor was used, which was placed on the walls of the conical diffuser. As a result, it was shown that effect of the vortex precession occurs in the conical diffuser. The stabilizing devices substantially influence the amplitude-frequency characteristics of the pressure fluctuations. It was possible to achieve complete suppression of the precessing vortex and drastically reduce the pressure pulsations by installation of thegrooves extending in the axial direction.