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contributor authorUntaroiu, Alexandrina
contributor authorHayrapetian, Vahe
contributor authorUntaroiu, Costin D.
contributor authorWood, Houston G.
contributor authorSchiavello, Bruno
contributor authorMcGuire, James
date accessioned2017-05-09T00:58:58Z
date available2017-05-09T00:58:58Z
date issued2013
identifier issn0098-2202
identifier otherfe_135_5_051104.pdf
identifier urihttp://yetl.yabesh.ir/yetl/handle/yetl/151848
description abstractRotordynamic instability due to fluid flow in seals is a well known phenomenon that can occur in pumps as well as in steam turbines and air compressors. While analysis methods using bulkflow equations are computationally efficient and can predict dynamic properties fairly well for short seals, they often lack accuracy in cases of seals with complex geometry or with large aspect ratios (L/D above 1.0). This paper presents the linearized rotordynamic coefficients for a liquid seal with large aspect ratio subjected to incompressible turbulent flow. The fluidinduced forces acting on the rotor are calculated by means of a threedimensional computational fluid dynamics (3DCFD) analysis, and are then expressed in terms of equivalent linearized stiffness, damping, and fluid inertia coefficients. For comparison, the seal dynamic coefficients were calculated using two other codes: one developed with the bulk flow method and one based on the finite difference method. The three sets of dynamic coefficients calculated in this study were used then to predict the rotor dynamic behavior of an industrial pump. These estimations were then compared to the vibration characteristic measured during the pump shop test, results indicating that the closest agreement was achieved utilizing the CFD generated coefficients. The results of rotor dynamic analysis using the coefficients derived from CFD approach, improved the prediction of both damped natural frequency and damping factor for the first mode, showing substantially smaller damping factor which is consistent with the experimentally observed instability of the rotorbearing system. As result of continuously increasing computational power, it is believed that the CFD approach for calculating fluid excitation forces will become the standard in industry.
publisherThe American Society of Mechanical Engineers (ASME)
titleOn the Dynamic Properties of Pump Liquid Seals
typeJournal Paper
journal volume135
journal issue5
journal titleJournal of Fluids Engineering
identifier doi10.1115/1.4023653
journal fristpage51104
journal lastpage51104
identifier eissn1528-901X
treeJournal of Fluids Engineering:;2013:;volume( 135 ):;issue: 005
contenttypeFulltext


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