{"title":"Experimental Investigation of Acoustical Coupling between Cavity Flow and Cross Cylinder Wake","authors":"Hao Guo, Xuan Liang, T. Hu, Peiqing Liu","doi":"10.2514/6.2018-3471","DOIUrl":"https://doi.org/10.2514/6.2018-3471","url":null,"abstract":"","PeriodicalId":429337,"journal":{"name":"2018 AIAA/CEAS Aeroacoustics Conference","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124093875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
N. A. Balantrapu, Russell J. Repasky, Liselle A. Joseph, W. Devenport
{"title":"The Dynamic Response of a Pinhole Microphone under Flows of Varying Shear Stress","authors":"N. A. Balantrapu, Russell J. Repasky, Liselle A. Joseph, W. Devenport","doi":"10.2514/6.2018-3933","DOIUrl":"https://doi.org/10.2514/6.2018-3933","url":null,"abstract":"","PeriodicalId":429337,"journal":{"name":"2018 AIAA/CEAS Aeroacoustics Conference","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127773442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Manjunath, F. Avallone, D. Casalino, D. Ragni, M. Snellen
Acoustic liners are widely used as noise suppression devices, for example in aircraft engines. The effectiveness of the liners is measured through the impedance. In the present study, using a lattice-Boltzmann solver, the response of two liner geometries to grazing acoustic waves is examined. The two geometries have porosity equal to 0.99% and 6.89%, respectively. Impedance is computed using the traditional in-situ method. The results from the simulation are validated against previous experimental data, DNS data and predictions from semi-empirical models. Results show agreement with these reference data, allowing to use the computational setup for further analysis with a realistic liner configuration in the presence of a grazing flow.
{"title":"Characterization of Liners using a Lattice-Boltzmann Solver","authors":"P. Manjunath, F. Avallone, D. Casalino, D. Ragni, M. Snellen","doi":"10.2514/6.2018-4192","DOIUrl":"https://doi.org/10.2514/6.2018-4192","url":null,"abstract":"Acoustic liners are widely used as noise suppression devices, for example in aircraft engines. The effectiveness of the liners is measured through the impedance. In the present study, using a lattice-Boltzmann solver, the response of two liner geometries to grazing acoustic waves is examined. The two geometries have porosity equal to 0.99% and 6.89%, respectively. Impedance is computed using the traditional in-situ method. The results from the simulation are validated against previous experimental data, DNS data and predictions from semi-empirical models. Results show agreement with these reference data, allowing to use the computational setup for further analysis with a realistic liner configuration in the presence of a grazing flow.","PeriodicalId":429337,"journal":{"name":"2018 AIAA/CEAS Aeroacoustics Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128731760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Karl-Stéphane Rossignol, J. Delfs, M. Mößner, D. Gély, J. Bulté, F. Hutcheson
This paper presents the experimental results of a study conducted at DLR, ONERA and NASA on the shielding of sound by an NACA 0012 airfoil. The work presented was done in the context of the AVT-233 working group of the Science and Technology Organization (STO) of NATO. The experiments were conducted in the DLR Acoustic Wind Tunnel Braunschweig (AWB), the ONERA F2 tunnel and the NASA Quiet Flow Facility (QFF), with the goal of investigating facility-to-facility effects on the collected data. Two impulsive source concepts were used in the course of these experiments, DLR’s laser sound source and ONERA’s electric discharge source (SPARC). The collected data reveal that the different tunnel environments do not strongly affect the results obtained with either source. The laser sound source is found to deliver consistent results in all three wind tunnels, for the 7, 14 and 28 kHz octave bands at M=0.0 and M=0.16. In the highest octave band considered (56 kHz), the results are found to be very sensitive to the choice of operating parameters. The SPARC source also delivered consistent results in the low frequency range, in both the F2 tunnel and the AWB, for both Mach numbers tested. This joint effort has led to the development of a highly valuable database for the validation of shielding prediction tools.
{"title":"Experimental Investigations on Noise Shielding: Dependency on Reference Noise Source and Testing Environment","authors":"Karl-Stéphane Rossignol, J. Delfs, M. Mößner, D. Gély, J. Bulté, F. Hutcheson","doi":"10.2514/6.2018-2820","DOIUrl":"https://doi.org/10.2514/6.2018-2820","url":null,"abstract":"This paper presents the experimental results of a study conducted at DLR, ONERA and NASA on the shielding of sound by an NACA 0012 airfoil. The work presented was done in the context of the AVT-233 working group of the Science and Technology Organization (STO) of NATO. The experiments were conducted in the DLR Acoustic Wind Tunnel Braunschweig (AWB), the ONERA F2 tunnel and the NASA Quiet Flow Facility (QFF), with the goal of investigating facility-to-facility effects on the collected data. Two impulsive source concepts were used in the course of these experiments, DLR’s laser sound source and ONERA’s electric discharge source (SPARC). The collected data reveal that the different tunnel environments do not strongly affect the results obtained with either source. The laser sound source is found to deliver consistent results in all three wind tunnels, for the 7, 14 and 28 kHz octave bands at M=0.0 and M=0.16. In the highest octave band considered (56 kHz), the results are found to be very sensitive to the choice of operating parameters. The SPARC source also delivered consistent results in the low frequency range, in both the F2 tunnel and the AWB, for both Mach numbers tested. This joint effort has led to the development of a highly valuable database for the validation of shielding prediction tools.","PeriodicalId":429337,"journal":{"name":"2018 AIAA/CEAS Aeroacoustics Conference","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133744142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Resonance and Tones in Dual-Stream Nozzles induced by vortex shedding from struts","authors":"I. Milanović, K. Zaman, C. Miller","doi":"10.2514/6.2018-3939","DOIUrl":"https://doi.org/10.2514/6.2018-3939","url":null,"abstract":"","PeriodicalId":429337,"journal":{"name":"2018 AIAA/CEAS Aeroacoustics Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131193383","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The National Aeronautics and Space Administration (NASA) Acoustic Research Measurements (ARM) project was established to evaluate via flight tests the noise reduction benefits of the Adaptive Compliant Trailing Edge (ACTE) technology along with various main landing gear noise reduction concepts. The ACTE replaces the original Fowler flaps on the NASA SubsoniC Research Aircraft Testbed (SCRAT), thus creating a seamless trailing edge that provides significant noise abatement benefits. The various main landing gear noise reduction concepts are grouped under the LAnding Gear noisE Reduction (LAGER) task and consist of fairings placed on the main landing gear along with two separate treatments applied to the main landing gear wheel well cavities. This paper discusses the tasks necessary to prepare each of these technologies for the ARM flights. The LAGER hardware was taken from model-scale concepts tested in wind tunnels to flight hardware, which had to be cleared as airworthy for the ARM flights. The ACTE flaps were initially intended to be removed from the SCRAT prior to the start of the ARM project. Retaining the ACTE flaps on the aircraft for a longer period of time to support the ARM flights resulted in additional inspections and considerations since the ACTE flaps were flown longer and at certain flight conditions for longer periods of time than initially analyzed. The flight and ground operations required for the ARM tests required extensive coordination among multiple groups and organizations in order to be successful. This paper provides an overview of the hardware development, ground operations, and flight operations which went into acquiring the desired acoustic measurements. In general, the flights were successful and demonstrated the noise reduction benefits of the ACTE flaps, the LAGER gear fairings, and the LAGER gear cavity treatments.
{"title":"Flight and Ground Operations in Support of Airframe Noise Reduction Tests","authors":"E. Baumann, E. Waggoner","doi":"10.2514/6.2018-2970","DOIUrl":"https://doi.org/10.2514/6.2018-2970","url":null,"abstract":"The National Aeronautics and Space Administration (NASA) Acoustic Research Measurements (ARM) project was established to evaluate via flight tests the noise reduction benefits of the Adaptive Compliant Trailing Edge (ACTE) technology along with various main landing gear noise reduction concepts. The ACTE replaces the original Fowler flaps on the NASA SubsoniC Research Aircraft Testbed (SCRAT), thus creating a seamless trailing edge that provides significant noise abatement benefits. The various main landing gear noise reduction concepts are grouped under the LAnding Gear noisE Reduction (LAGER) task and consist of fairings placed on the main landing gear along with two separate treatments applied to the main landing gear wheel well cavities. This paper discusses the tasks necessary to prepare each of these technologies for the ARM flights. The LAGER hardware was taken from model-scale concepts tested in wind tunnels to flight hardware, which had to be cleared as airworthy for the ARM flights. The ACTE flaps were initially intended to be removed from the SCRAT prior to the start of the ARM project. Retaining the ACTE flaps on the aircraft for a longer period of time to support the ARM flights resulted in additional inspections and considerations since the ACTE flaps were flown longer and at certain flight conditions for longer periods of time than initially analyzed. The flight and ground operations required for the ARM tests required extensive coordination among multiple groups and organizations in order to be successful. This paper provides an overview of the hardware development, ground operations, and flight operations which went into acquiring the desired acoustic measurements. In general, the flights were successful and demonstrated the noise reduction benefits of the ACTE flaps, the LAGER gear fairings, and the LAGER gear cavity treatments.","PeriodicalId":429337,"journal":{"name":"2018 AIAA/CEAS Aeroacoustics Conference","volume":"107 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131508443","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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