Eventos Anais de eventos
ENCIT 2018
Brazilian Congress of Thermal Sciences and Engineering
Numerical and experimental characterization of subsonic flow around a circular cylinder: wind tunnel measurement capabilities and turbulence models suitability
Submission Author:
Leonardo Alexis Flores Tymchuk , Lima , Peru
Co-Authors:
Leonardo Alexis Flores Tymchuk, Cesar Celis, Armando Blanco
Presenter: Leonardo Alexis Flores Tymchuk
doi://10.26678/ABCM.ENCIT2018.CIT18-0195
Abstract
Through a detailed numerical and experimental characterization of subsonic flow around a circular cylinder, the measurement capabilities of a wind tunnel are assessed in this work. More specifically, computational fluid dynamics (CFD) results are used to determine the flow range in which the wind tunnel produces accurate results, given the current limitations of the instrumentation available in the wind tunnel. The influence of three turbulence models, namely shear-stress transport (SST) k-ω, Transition SST and Scale-Adaptive Simulation (SAS), on the obtained numerical results, is analyzed as well. For the numerical computations, a range of Reynolds numbers from 10 to 1.4x105 is covered accounting for subsonic and incompressible flow. For the experimental analysis in turn, a Reynolds number range up to 1.2x105 is studied in the wind tunnel. Aiming to reduce the associated computational cost, several simulation strategies taking into account different solution methods, under-relaxation factors and time discretization schemes are studied as well. The influence of turbulence models on the obtained numerical results is qualitatively analyzed considering contours of velocity, vorticity, shear layers, transition to turbulence, among others. In quantitative terms, the referred influence is discussed accounting for drag, lift and pressure coefficients, as well as for the boundary layer separation angle. Variations of key parameters as a function of Reynolds number and along their frequencies spectra are properly discussed as well. A relative good agreement is noticed between the wind tunnel measurements and experimental measurements from the literature. A relative good agreement between the numerical results obtained here for the laminar regime and those associated with similar studies carried out in the past is observed as well. Nonetheless, larger discrepancies were found at turbulent regimes between the numerical simulations and experimental measurements from this work and literature. The results from this work will be used in future to specify new and more sophisticated instrumentation to be installed in the particular wind tunnel analyzed here.
Keywords
circular cylinder, Computational Fluid Dynamics, measurements, Wind Tunnel
