Many current and future aircraft designs deal with the problem of jet noise prediction methods when the flow interacts with part of the airplane structure. Data regarding how a planar surface interacts with a jet are limited. To this purpose, an experimental study has been conducted in the Roma TRE semi-anechoic chamber of the Aeroacoustics Laboratory using a Background Oriented Schlieren (BOS) technique. The technique was applied to a compressible circular jet flow interacting with a flat-plate positioned parallel to the axial direction. The aim of the work is to investigate how the planar surface interacts with the high-speed jet flow and influences the shock cell structures, for this reason the BOS set up has been configured specifically to meet the optical constrains related to the jet-surface geometry. Measurements have been performed at different Mach numbers in high subsonic, sonic and slightly under-expanded conditions and considering three relative positions of the plate with respect to the jet axis. The density gradient field is evaluated using a cross-correlation algorithm. The acquired images have been post-processed to obtain the density field by numerical integration of the Poisson equation and analysed together with the wall pressure signals. To improve the solution a patching technique procedure has been developed.
de Paola, E., Di Marco, A., Meloni, S., Camussi, R. (2019). Density measurements of a compressible jet flow interacting with a tangential flat plate using background-oriented schlieren. In Springer Proceedings in Physics - 8th iTi Conference on Turbulence, 2018 (pp.185-190). GEWERBESTRASSE 11, CHAM, CH-6330, SWITZERLAND : SPRINGER INTERNATIONAL PUBLISHING AG [10.1007/978-3-030-22196-6_29].
Density measurements of a compressible jet flow interacting with a tangential flat plate using background-oriented schlieren
de Paola E.;Di Marco A.;Meloni S.;Camussi R.
2019-01-01
Abstract
Many current and future aircraft designs deal with the problem of jet noise prediction methods when the flow interacts with part of the airplane structure. Data regarding how a planar surface interacts with a jet are limited. To this purpose, an experimental study has been conducted in the Roma TRE semi-anechoic chamber of the Aeroacoustics Laboratory using a Background Oriented Schlieren (BOS) technique. The technique was applied to a compressible circular jet flow interacting with a flat-plate positioned parallel to the axial direction. The aim of the work is to investigate how the planar surface interacts with the high-speed jet flow and influences the shock cell structures, for this reason the BOS set up has been configured specifically to meet the optical constrains related to the jet-surface geometry. Measurements have been performed at different Mach numbers in high subsonic, sonic and slightly under-expanded conditions and considering three relative positions of the plate with respect to the jet axis. The density gradient field is evaluated using a cross-correlation algorithm. The acquired images have been post-processed to obtain the density field by numerical integration of the Poisson equation and analysed together with the wall pressure signals. To improve the solution a patching technique procedure has been developed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.