Aktive Kontrolle von Längswirbeln

• Antragsteller: Professor Dr.-Ing. Christian Oliver Paschereit
• Fachliche Zuordnung: Strömungsmechanik
• Förderung: Förderung von 2006 bis 2012
• Projektkennung: Deutsche Forschungsgemeinschaft (DFG) - Projektnummer 27153271

• Erstellungsjahr: 2012

Zusammenfassung der Projektergebnisse

An active flow control method of an axis-symmetric jet was investigated which, when activated, generates streamwise vortices and thus enhances mixing of the jet flow with the ambient. The perimeter of the jet is equipped with six small flaps deflected away from the stream. Zero mass-flux perturbations were used to excite the flow. These excitations were introduced in the flow through slots at the base of the flaps. Each of the flaps can be excited independently. In the earlier phase of the project, the shape and angle of a single flap were optimized and the local effect on the jet analyzed. It was shown that the local mixing could be increased. In the later phase of the project, the effect of an array of six individually controllable flaps on the global jet behavior was investigated. Each of the flaps was designed to be excited in phase or with pre-fixed phase shift. Effects of frequency and amplitude on the flow momentum, streamwise vorticity, circulation and turbulence for a fixed flap deflection angle were part of the investigation. Data acquisitions were done using hotwire and stereo-PIV to acquire complete flow field information. The emphasis was placed on mapping the development of the trailing vortices in order to quantify the mixing achieved.

Projektbezogene Publikationen (Auswahl)

• “Active management of entrainment and streamwise vortices in an incompressible jet”. Proceedings of the 1st Conference on Active Flow Control, September 27-29, 2006, Berlin, Germany
  D. Greenblatt, Y. Singh, Y. Kastantin, C.N. Nayeri, C.O. Paschereit
  
• “Active and passive flow control of an incompressible axisymmetric jet”. Proceedings of ASME Turbo Expo 2008: Power for Land, Sea and Air, GT2008, June 9-13, Berlin, Germany, 2008
  Mohan, N. K. M., Greenblatt, D., Nayeri, C. N., Paschereit, C. O., Ramamurthi, P. N.
  
• “Active control of an incompressible axisymmetric jet”. Proceedings of the 9th Biennial ASME Conference on Engineering Systems Design and Analysis, ESDA08, July 7-9, Haifa, Israel, 2008
  Greenblatt, D., Singh, Y., Mohan, N. K. D., Nayeri, C. N., Paschereit, C. O.
  
• “Active Control of an Incompressible Axisymmetric Jet using Flaps”. Proceedings of the Sixth International Symposium on Turbulence and Shear Flow Phenomena (TSFP6), June 22 - 24, 2009, Seoul, South Korea
  Y. Singh, D. Greenblatt, C.N. Nayeri, C.O. Paschereit
  
• “Active Control of an Incompressible Axisymmetric Jet Using Flaps and Zero Mass- flux Excitation”. AIAA-2010-4417, 40th AIAA Fluid Dynamics Conference and Exhibit, June 2010
  Singh, Y., Mueller-Vahl, H., Greenblatt, D., Nayeri, C.N., Paschereit, C.O.