Scientific results:
- We have developed and tested a method for the azimuthal decomposition of noise from a reactive jet near a hard reflecting surface. For the first time in the world we have conducted measurements of azimuthal modes of noise of an aircraft engine jet on a full-scale test rig.
- We have developed and tested in laboratory conditions a methodology for measuring the mode composition of noise in the air-intake channel of an air engine.
- For the first time in the Russian practice we have received experimental data on the azimuthal composition of noise in an air-intake channel and performed a localization of noise sources from a modern aircraft engine.
- We have developed a methodology for the experimental measurement of acoustic and flight aerodynamic characteristics of moving multipole sources of various sizes on the basis of multichannel measurement methods. A beam forming method has been developed and tested for localizing a dipole-type noise source.
- We have developed and tested a method for measuring the azimuthal and radial structure of a noise field in a channel in the presence of impedance reflection on the walls. A methodology has been developed for choosing a placement scheme with improved noise cancellation or cells of noise-canceling structures with enhanced noise cancellation in a wide range of frequencies, a method for determining acoustic characteristics of large noise-canceling structures at a specified azimuthal modal composition of a noise field.
Implemented results of research:
- We have created computer software for determining the optimal locations of microphones in flat and ring multmicrophone grids. We processed the measured acoustic data that allow to determine the modal composition of noise in a channel of an aircraft engine. Two certificates of state registration of software programs have been obtained. These programs were used to refine the testing program and for processing results of acoustic measurements of an aircraft engine on an open test bench.
- The laboratory has created computer programs for designing highly-efficient noise-canceling structures (NCS) for channels of aircraft engines. Using this software, we have developed NCS with a resonance cells with new configurations that show better noise cancellation in a wide range of frequencies. Three patents and four certificates of state registration of software programs have been obtained.
- A technology has been developed for creating NCSs with a higher level of noise cancellation, created prototypes of full-scale NCSs that can be installed onto a prospective Russian aircraft engine, one patent has been obtained.
- An input device has been developed for a 40-channel rotating mode generator, one patent has been obtained.
- An interferometer has been developed with controlled contraction of the NCSs sample that allows to reduce the dispersion of the measured acoustic characteristics, one patent has been obtained.
Education and career development:
- We have compiled and launched 7 disciplines in the education process of Perm National Research Polytechnic University in the direction of master’s degree training «Aircraft engines»: «Mathematical foundations of acoustics», «Basics of acoustics research», Aeroacoustics», «Modern methods of acoustic measurements», «Theory and practice of acoustic signals and fields processing», «Finite-element methods in problems of acoustics», «Numerical modeling of acoustic processes in aircraft engines».
- Two additional training programs has been created for professionals from other organizations: 21 professionals have completed training.
- 14 employees of the Laboratory have enrolled in the postgraduate school.
- One Doctor of Sciences dissertation, 4 Candidate of Sciences dissertations, 5 specialist s degree theses, 4 master’s degree theses, 5 bachelor’s degree theses have been prepared and defended.
Organizational and structural changes:
We have created the unique scientific facility «Acoustically damped chamber with aerodynamic noise sources», it is actively used for conducting research works for grants and commercial agreements.
Collaborations:
- Central Aerohydrodynamic Institute – TsAGI (Russia), «UEC–Aviadvigatel» JSC (Russia): joint research, publications, internships of postgraduate and undergraduate students and young researchers.
- Bruel&Kjaer (Denmark): joint research, creating an optimized antenna for identifying the modal structure of noises in cylindrical channel.
