Mehanika mašina i mehanizama - modeli i matematičke metode, 17. decembar 2019.

Naredni sastanak Seminara biće održan u utorak, 17. decembra 2019. u sali 301f Matematičkog instituta SANU sa početkom u 18 časova.

Predavač: Đorđe S. Čantrak, University of Belgrade, Faculty of Mechanical Engineering


Apstrakt: Experimentally obtained velocity and pressure fields behind the CRM (common research model) wing are studied. CRM is designed by NASA and Boeing. Measurements have been performed in the windtunnel at 50 m/s and Reynolds number at wing tip chord ReC ≈ 2.68·105, by using optical technique time-resolved stereo particle image velocimetry (TR-SPIV) and cobra probe with four holes. Ten measurements have been performed for each angle of attack (0o, 2o and 4o). Experimentally determined all three velocity components and turbulent stresses enabled vortex core dynamics observation and constitution of the anisotropy invariant maps for various angles of attack of the CRM. Pressure and velocity field measurements have been performed in, even wider, domain afterwards for the same angles of attack by use of the cobra probe. Here will be presented results of the numerical determination of the pressure field on the basis of the TR-SPIV velocity measurements and pressure boundary conditions, as well experimentally determined. Results are obtained solving the incompressible momentum equation, i.e., Poisson equation. It is assumed that the flow is quasi two-dimensional, where the additional terms for 3D flow are neglected. Analysis approved good agreement of the experimentally determined pressure field and one numerically modelled on the basis of the simplified Navier-Stokes equation, TR-PIV results and pressure boundary conditions. Presented method enables pressure field determination by use of the TR-SPIV measurement technique, which is significantly faster than pressure field scanning with classical probes. This is important for time reduction of researches in wind tunnels.

Ostavite vaš komentar:

(nece biti prikazano)