A Standard Method to Determine Loss Coefficients of Conduit Components Based on the Second Law of Thermodynamics
作者： Bastian Schmandt , Heinz Herwig
关键词: Mechanics 、 Computer simulation 、 Gear pump 、 Open-channel flow 、 Reynolds number 、 Laminar flow 、 Flow conditioning 、 Mechanical engineering 、 Engineering 、 Second law of thermodynamics 、 Entropy (information theory)
摘要: Losses in conduit components of a pipe system can be accounted for by using component specific loss coefficients K. Especially mini- and micro-systems an exact knowledge these (which laminar flow strongly depend on the Reynolds number) is important. Limited space will generally lead to high loss-contribution single compared contribution straight channels. The determination K-values based numerical simulation Second Law Analysis (SLA) has turned out very attractive method. field shows distribution losses upstream downstream lengths impact (Lu, Ld) where otherwise fully developed affected component. SLA-Method introduced as standard method, illustrated validated with highly accurate measurements 90 deg bend square cross section. local entropy generation rates are computed carefully interpreted. Component values K, Lu Ld collected table plots rate along bend’s centerline. Validation achieved experimental results from test facility exclusively built this purpose: Laminar induced controlled gear pump polydimethylsiloxanes different viscosities working fluids.Copyright © 2012 ASME
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