Catalano, Pietro (2009) Aerodynamic Analysis of Low Reynolds Number Flows. [Tesi di dottorato] (Unpublished)

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Item Type: Tesi di dottorato
Language: English
Title: Aerodynamic Analysis of Low Reynolds Number Flows
Creators:
CreatorsEmail
Catalano, Pietrop.catalano@cira.it
Date: 30 November 2009
Number of Pages: 108
Institution: Università degli Studi di Napoli Federico II
Department: Ingegneria aerospaziale
Doctoral School: Ingegneria industriale
PHD name: Ingegneria aerospaziale, navale e della qualità
PHD cycle: 22
PHD Coordinator:
nameemail
Moccia, Antonioantonio.moccia@unina.it
Tutor:
nameemail
Tognaccini, Renatortogna@unina.it
Date: 30 November 2009
Number of Pages: 108
Uncontrolled Keywords: Low Reynolds, Turbulence Modelling
MIUR S.S.D.: Area 09 - Ingegneria industriale e dell'informazione > ING-IND/06 - Fluidodinamica
Date Deposited: 20 May 2010 07:51
Last Modified: 30 Apr 2014 19:38
URI: http://www.fedoa.unina.it/id/eprint/3828

Abstract

An aerodynamic analysis of low-Reynolds number flows is presented. The focus is placed on the laminar separation bubbles, a peculiar phenomenon of these kind of flows. The only simulations techniques feasible to be applied to complex configurations appear to be the methods based on the Reynolds Averaged Navier Stokes equations. A critical point is the turbulence modelling. In fact, the turbulence models are calibrated for flows at high Reynolds number with separation in the turbulent regime. The flow over a flat plate with an imposed pressure gradient, and around the Selig-Donavan 7003 airfoil is considered. Large eddy simulations have also been performed and used as reference for the RANS results. Laminar separation bubbles have been found by the Spalart-Allmaras and the k-w SST turbulence models. The models have been used without prescribing the transition location and assuming low values of the free-stream turbulence. The main results have been achieved for the k-w SST turbulence model. This model is very reliable for transonic flows at high Reynolds number, but has shown limits when applied to low-Reynolds number flows. A modification of the model has been proposed. The modified model, named as k-w SST-LR, has provided a correct simulation of the boundary layer in the tests performed at low and high Reynolds numbers. The laminar separation bubble arising of the SD 7003 airfoil has been well captured. The accuracy of the new model is not reduced in transonic regime.

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