Experimental investigation of shock wave patterns over a NACA 0012 profile

Layra Mendonça¹; Ana Cristina Avelar¹; João Batista Pessoa Falcão Filho¹; Cayo Prado Fernandes Francisco¹

¹ Instituto de Aeronáutica e Espaço

doi:10.20906/CPS/COB-2015-1605

Resumo

The transonic range is a very important part of an aerospace vehicle flight envelope because of the very complex flow phenomena happening in this speed range, as for example shock wave occurrences and associated boundary-layer interactions. The shock waves formation patterns can be very different depending on the flow conditions, mainly regarding the Mach number. In some conditions the classical phenomena of shock-wave/boundary-layer interactions take place. The present study is aimed at investigating the shock wave formation patterns over a NACA 0012 profile in the transonic regime as the Mach number and the angle of attach is varied. The angle of attack will be varied between 2 and 10 degrees and the Mach number between 0.6 and 1.1. In some selected configurations, with interesting shock wave patterns, the Reynolds number effects in the flow field over the model will be investigated using transition strips, in an attempt to predict the physical phenomena occurring in a flight condition, once the Reynolds number in a flight condition of a real space vehicle is very high. Consequently, the laminar to turbulent boundary layer transition occurs very soon, still in the beginning of the fore-body section. On the other hand, in wind tunnel tests, the flow is expected to be mostly laminar over a great extension of the scaled model. So, in order to analyze the Reynolds effects, transition strip will be used to accelerate the laminar to turbulent boundary layer transition, simulating in this way a full Reynolds number condition. The techniques of Schlieren flow visualization and pressure sensitive paint (PSP) will be used in the experimental analyses. The experiments will be conducted in the Pilot Transonic wind tunnel of the Instituto de Aeronáutica e Espaço (IAE), TTP. This facility allows aerodynamic tests in Mach number varying from 0.2 to 1.3 with automatic controls of pressure (from 0.5 bar to 1.2 bar), temperature and humidity. The flow in its test section of 0.25 m x 0.30 m is continuously driven by a main two-st

Palavras-chave: Shock waves; Transonic Regime; Wind tunnel