Affiliations: [a] São Paulo State University, Rua Cristóvão
Colombo, 2265 – São José do Rio Preto-SP, 15054-000, Brazil | [b] College of Electrical Engineering, Zhejiang
University, Hangzhou, 310027, People Republic of China | [c] Institute for Advanced Studies, São José dos
Campos, 12228-001, Brazil
Correspondence:
[*]
Corresponding author: José Márcio Machado, São Paulo
State University, Rua Cristóvão Colombo, 2265, Jardim Nazareth São
José do Rio Preto-SP 15054-000, Brazil. E-mail: [email protected]
Abstract: This work describes an optical device for the simultaneous recording
of shadowgrams and schlieren images, and some results are presented concerning
its applications to the study of plasma assisted flow control in airfoil
models. This approach offers many advantages in comparison to other methods,
specially because the use of tracer particles (like smoke in wind tunnels) is
not required for the experiments, thus avoiding contaminations in the electric
discharges or air flows. Besides, while schlieren images reveal the refractive
index gradients in the area of study, shadowgrams detect the second order
spatial derivatives of the refractive indexes. Therefore, the simultaneous
recording of these different images may give interesting information about the
phenomena under study. In this paper, these images were used to confirm the
existence of vortex structures in the flow induced by corona discharges on
airfoil models. These structures are a possible explanation for the effects of
drag reduction and lift force increasing, which have been reported in
experiments of plasma assisted Aerodynamics.
Keywords: Plasma assisted aerodynamics, corona discharges, air flow control
