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OverviewA new approach to turbulence modeling in unsteady developed flows has recently been introduced, based on results of rapid distortion theory. The approach involves closing the k-epsilon equations for the organized unsteady component of the flow by modeling local unsteadiness as a rapid distortion of the local structure of the parent turbulent flow, in terms of an effective strain parameter alpha(sub eff). In this paper, the phase-conditioned equations of motion are developed to accommodate a new unsteady dissipation model and local effects of the slow-relaxation time scale of the parent flow. The model equations are tested against measurements of the response of a fully-developed turbulent pipe flow to the superposition of sinusoidal streamwise oscillation. Good agreement is found between measurements and predictions over a wide range of frequencies of unsteadiness, indicating that this approach may be particularly well suited to modeling of unsteady turbulent flows which are perturbations about a well characterized mean. Brereton, G. J. and Mankbadi, R. R. Glenn Research Center NASA-TM-106249, ICOMP-93-22, E-7971, NAS 1.15:106249 NCC3-233; RTOP 505-90-5K... Full Product DetailsAuthor: National Aeronaut Administration (Nasa)Publisher: Createspace Independent Publishing Platform Imprint: Createspace Independent Publishing Platform Dimensions: Width: 21.60cm , Height: 0.20cm , Length: 27.90cm Weight: 0.115kg ISBN: 9781725023673ISBN 10: 1725023679 Pages: 38 Publication Date: 10 August 2018 Audience: General/trade , General Format: Paperback Publisher's Status: Active Availability: In Print This item will be ordered in for you from one of our suppliers. Upon receipt, we will promptly dispatch it out to you. For in store availability, please contact us. Table of ContentsReviewsAuthor InformationTab Content 6Author Website:Countries AvailableAll regions |
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