Intermittent round jet controlled by lateral pulse-modulated synthetic jets

0504632 - ÚT 2020 RIV JP eng J - Journal Article
Broučková, Zuzana - Trávníček, Zdeněk
Intermittent round jet controlled by lateral pulse-modulated synthetic jets.
Journal of Visualization. Roč. 22, č. 3 (2019), s. 459-476. ISSN 1343-8875. E-ISSN 1875-8975
R&D Projects: GA ČR(CZ) GA16-16596S
Institutional support: RVO:61388998
Keywords : flow control * pulse modulation * synthetic jet * flow visualization * hot-wire anemometry
OECD category: Aerospace engineering
Impact factor: 0.926, year: 2019
Method of publishing: Limited access
https://link.springer.com/article/10.1007%2Fs12650-019-00550-z

A round air jet was actively controlled by a pair of lateral control jets. The control jets were generated by a pair of opposing synthetic jet actuators, which were driven by the pulse-modulated sinusoidal signal. Two carrier frequencies were tested, namely 160Hz and 840Hz. Moreover, control jets driven by un-modulated sinusoidal signals were also tested. An unforced continuous jet was used as the reference case, and for all cases, the Reynolds number of the main round jet was 1570 (related to the nozzle exit diameter of 10mm). Experiments (flow visualization and hot-wire anemometry) revealed that the flow control caused a suppression of the jet core and a more rapid jet flow decay. In addition, the pulse modulation caused jet intermittency that was distinguished by the periodicity of the time-averaged and fluctuating velocity components. For the case of the lower carrier frequency of 160Hz, a flapping motion of the controlled jet occurred and the jet formed a zigzag pattern.
Permanent Link: http://hdl.handle.net/11104/0298228