Laboratório de Vibrações e Acústica

Project Description: Speech recognition tests using sentences are considered more reliable in hearing assessment and seek to simulate everyday communication situations, in which the extent of the utterance to be recognised and linguistic complexity are factors taken into account, fundamental to estimate complaints of difficulty in understanding speech. Studies of the national literature with Speech Perception Tests (Testes de Percepção de Fala – TPF) have found that there is no uniformity in the use of these materials, which makes it difficult for research purposes, comparison of findings and evaluation of data by the Ministry of Health. This lack of standardization in relation to the application of the Speech Perception Tests, can lead to erroneous indications of candidates for the use of cochlear implants, implying misuse of the resources of the Unified Health System (Sistema Único de Saúde – SUS). The project therefore aims to develop brazilian portuguese signals and competitive noise signals, such as babble noise in the Portuguese region.

Coordinator/ Participants: Prof. Stephan Paul (LVA); Ana Carolina de Assis Moura Ghirardi (Phonoaudiology UFSC); Maria Madalena Canina Pinheiro (Phonoaudiology UFSC); Isadora Koerich (Phonoaudiology UFSC); Isadora Rosseto (Phonoaudiology UFSC)

Partners: Course of Phonoaudiology UFSC.

Project Description: This is a project funded by FINEP in partnership with the Center for Oncology Research of Santa Catarina (Centro de Pesquisas Oncológicas de Santa Catarina – CEPON) and with the cooperation of teachers Ana Carolina Ghirardi (Department of Phonoaudiology, UFSC) and Carlos Rodrigo Roesler (Biomechanical Engineering Laboratory LEBm). Its goal is to meet the demand of patients who have lost their voice as a result of laryngeal cancer. These are set as goals: 

1) Develop a voice prosthesis by similarity, based on imported tracheoesophageal valves, currently available on the market;

2) Develop the patent of a new tracheoesophageal prosthesis, which allows its adequacy according to the physiological characteristics of each patient.

To achieve these goals, different research is being carried out within the project, encompassing the manufacture, testing and optimization of voice prostheses, the study of the dynamic behavior of the pharyngoesophageal segment (which is the sound source of the tracheoesophageal voice) and the study of the mechanics of the voice produced by the vocals folds.

Coordinator/ Participants:Andrey Ricardo da Silva(coordinator); Ana Carolina Ghirardi (collaborator); Carlos Rodrigo Roesler (collaborator); André Miazaki Tourinho (participant/LVA UFSC); Nivaldo Lopo Júnior (participant/ LVA UFSC); Maria Júlia Mezzari (participant/ LVA UFSC); João Pedro Petrassi(participant/ LVA UFSC); Luciano Fontes e Silva (participant/ LEBm UFSC); Gabrieli Cercal (participant/ Phonoaudiology UFSC); Isadora Nunes (participant/ Phonoaudiology UFSC).

Publications: Santos, F. H. T., da Silva, A. R., Tourinho, A. M. C. & Erath, B. Influence of position and angulation of a voice prosthesis on the aerodynamics of the pseudo-glottis. Journal of Biomechanics 125, (2021). http://dx.doi.org/10.1016/j.jbiomech.2021.110594

Tourinho, A. M. da C., da Silva, A. R., dos Santos, L. R. M., Thomaz, F. B. & Vieira, E. G. A study on tracheoesophageal phonation based on a collapsible channel model. The Journal of the Acoustical Society of America 149, (2021). http://dx.doi.org/10.1121/10.0003817

Project images:

Image 1: Experimental bench for the study of flow through synthetic vocal folds.	Image 2: Detail of synthetic vocal folds mounted on the experimental bench.
Image 3: Modeling of the new prototype of voice prosthesis developed from optimizations.	Image 4: Voice prosthesis manufactured for initial testing.
Image 5: CFD simulation of air flow through the prosthesis.	Image 6: CFD simulation of air flow through the prosthesis.
Image 7: Simulation of air flow through a voice prosthesis.

Project Description: The project involves the application of traditional numerical simulation methods in the area of acoustic and vibrations, as well as the development of tools and/or new methods, focusing on fluid-structure coupling problems (vibro-acoustic). Such methods are essential for project analysis and development in the naval, automotive, aeronautics and aerospace industries, since with them it is possible to simulate the vibratory and acoustic behaviors of their products and structures, predicting possible failures and improvements. An example of the use of such methods is the estimation of the internal noises of an automobile, enabling optimized projects in order to improve the comfort of its passengers.

Coordinator/Participants: Júlio Apolinário Cordioli (coordinator); Thiago Morhy Cavalcante (participant/ LVA UFSC); Racquel Knust Domingues (participant/ LVA UFSC).

Partners: ESI Group.

Project images: 

Image 1: Modeling the structural behavior of a vehicle chassis through the use of the Finite Element and Contour Elements Method.	Image 2: Modeling of a rocket (Saturn V) by the Finite Element Method.
Image 3: Modeling of the vibro-acoustic behavior of a helicopter through the use of Energy Statistical Analysis.	Image 4: Modeling a capsule of a rocket coming out of orbit through the use of Energy Statistical Analysis.

Description: The project aims to perform noise measurements of simplified models of eVTOL type aircraft. The tests are conducted in the semi-anechoic chamber of the Laboratory of Vibrations and Acoustics. The current setup allows for tests with insulated propellers, covering ranges of propeller diameters and typical application rotation speeds for small drones. New bench configurations are under development to assess the helix installation effect and the effect of acoustic interaction of multiple rotors.

Coordinator/ Participants: Prof. Júlio Apolinário Cordioli (coordinator); M. Eng. Lucas Araújo Bonomo (participant/LVA UFSC); Eng. Marcelo Henrique Martinelli Martins (participant/ LVA UFSC); Isabela Canello Resener (participant/ LVA UFSC); Nicolas T. Quintino (participant/ LVA UFSC); Prof. Andrey Ricardo da Silva (collaborator/ LVA UFSC).

Partners: EMBRAER

Project images: 

Image 1: Simplified eVTOL system installed in semi-anechoic chamber.	Image 2: Simplified eVTOL system installed in semi-anechoic chamber.
Image 3: Propeller installed on the countertop in semi-anechoic chamber.

Project Description: With the market increasingly competitive and with stricter regulations, compressors have been the product of intense research with the objective of reducing their sound emission and vibratory energy. This project acts in this direction through the following activities: analysis of mechanisms for generating and propagating vibratory energy in compressors; refrigerator noise analysis generated by compressors excites; development of tools for sound quality analysis of compressor-cooler system; development and application of optimization tools in compressors.

Coordinator/Participants: Prof. Arcanjo Lenzi (coordinator); Prof. Erasmo Felipe Vergara Miranda (collaborator); Dr. Olavo M. Silva (collaborator).

Partners: NIDEC/Embraco; Santa Catarina Teaching and Engineering Foundation (Fundação de Ensino e Engenharia de Santa Catarina – FEESC)

Project images: 

Image 1: Analysis of excites	Image 2: Modelling
Image 3: Interaction with the system (vibratory response of refrigerator cabinets)	Image 4: Sound quality

Project Description: In rescue and aeromedical transport operations, the exposure of crew and patients to sound pressure and vibration levels differ from a crew’s exposure of air or private taxi flights. This difference is primarily caused by the different flight configurations required in operations and also by the great variation of the exhibitions during a working day, since there are days with many operations and others with none. Flights patterns and aircraft types directly influence sound pressure levels and vibrations to which crews and patients are exposed. This research project aims to investigate the vibroacoustic conditions inside aircraft that are used by the security forces of the State of Santa Catarina during rescue missions and aeromedical transport.

Coordinator/ Participant: Prof. Stephan Paul (coordinator), Felipe Gelain (participant)

Project Description: The project aims to validate a numerical model in Lattice-Boltzmann method for impedance deduction of acoustic liners submitted to tangential flow. Validation involves comparing numerical results with experimental data, obtained in the rig of UFSC tests by different methods of eduction for a range of Mach numbers and sound pressure levels.  

The move towards a civil aviation market with less socio-environmental impact involves, for example, issues related to energy efficiency and noise control. 

One of the main noise control mechanisms used in modern aeronautical engines are the so-called acoustic liners (image 2). Liners are components installed in the nacelle of turbofan engines (image 3), whose main function is noise attenuation in the passing frequency of engine blades. This noise generation mechanism gained prominence as the mainone, as aeronautical engines evolved and began to have high ByPass Ratio ratios. 

In this sense, it is of primary importance the appropriate characterization of acoustic liners, which occurs through the determination of their acoustic impedance. It is interesting for the design of these components, however, that this characterization takes into account their actual operating conditions, such as the presence of tangential air flow over its perforated plate, so that the expected mitigation in different scenarios can be determined more atiatenly. In this way, potentially more efficient liners with less impact on the energy efficiency of the engines (drag) can be designed. 

The Laboratory of Vibrations and Acoustics of the Federal University of Santa Catarina has a test rig for acoustic liners mounted in anechoic chamber (image 4) able to impose the tangential flow conditions on the liner, and thus induce its impedance under conditions closer to the actual operating. 

However, recent studies have shown that the models of impedance deduction of flat walls used to represent the liner result in inconsistencies for the impedance values obtained. The main hypothesis is that such models do not adequately capture the physical interaction between the acoustic field and the turbulent boundary layer (TBL). The physical phenomena involved are of very small scale, and can only be visualized with the aid of numerical models.

Coordinator/ Participants: Prof. Júlio Apolinário Cordioli (coordinator); Prof. Andrey R. da Silva (collaborator/ LVA UFSC); Francesco Avallone (TUDelft); Damiano Casalino (TUDelft); Lucas Meirelles (participant/ LVA UFSC); Lucas Araújo Bonomo (participant/ LVA UFSC); Nicolas Quintino (participant LVA UFSC).

Partners: Delft Technical University (TUDelft); NASA’s Langley Research Center and Fabien Méry of the French Aerospace Laboratory (ONERA); Aeroacoustic Research Consortium (AARC).

Project images: 

Image 1: Turbulent boundary layer on perforated acoustic liner plate.	Image 2: Quematic structure of an acoustic liner.
Image 3: Acoustic liner in modern turbofan engine.	Image 4: Test rig for acoustic liners of LVA-UFSC.

Project Description: The project consists of the development of a numerical procedure, with experimental validation, for the analysis of acoustic pulsation and excessive vibrations in pipelines of oil processing units. The main result of this project is a computational procedure, in open source, which allows the determination of the vibroacoustic behavior of alternative compressor systems. The numerical methodology implemented differs from what is in commercial packages, because it innovates by optimizing the process for the proper analysis of the system in question, applying solution methods and contour conditions specific to the problem.

Coordinator/Participants: Prof. Arcanjo Lenzi (coordinator); Dr. Olavo M. Silva (collaborator); Eng. Jacson Gil Vargas (collaborator).

Partners: Petrobras; University Research; Extension Foundation (Fundação de Amparo à Pesquisa e Extensão Universitária – FAPEU).

Project images:

Image 1: Expansion chamber model with orifice plate.

Image 2: Duct and reservoir network model.

Project description: Today’s most advanced hearing prostheses such as cochlear implants feature an external unit to capture and process the sound signal to be delivered to the cochlea. Future cochlear implants should be totally implantable, which requires a sound or vibration sensor in the middle ear to be connected with a proper cable. While the vibration sensor is actually being prototyped the question of the cable and packaging of the sensor ist still to be solved. The requirements for such a cable are quite diverse, including high flexibility for almost the entire length but low flexibility at the terminals to prevent damage to the electrical connections, high puncture resistance to avoid damage during surgery, low water absorption, high electrical resistance of the isolator substrate, high conductivity of the wires, biocompatibility but repellent to tissue grow on the cable. Very high flexibility associated with a low mass is mandatory to prevent changes to the middle ear dynamics. Perylene based cables present themselves as viable options, but currently available parylene film cables suffer from different problems and might impose restrictions to the ossicular chain motion. The project aims to investigate the dynamics of such type of cables when coupled to the human middle ear by means of analytical and numerical models.

Coordinator/ Participants: Prof. Stephan Paul (coordinator); Vinicius Paegle (participant); Lucas Lobato (participant); Bruno van Bellen (participant)

Project description: The project aims to develop a proof of concept of a computational solution, in the form of a web-based application (app), to allow self-assessment of the auditory capacities of the adult population of Santa Catarina, for decision-making purposes about their hearing health and improvement of care by the hearing health care network in the state.

Coordinator/ Participants: Prof. Stephan Paul (coordinator); Profa. Fernanda Zucki (sub-coordinatora/ Phonoaudiology UFSC); Profa. Maria Madalena Canina Pinheiro (participant/ Phonoaudiology UFSC); Géssica de Souza (participant/ Phonoaudiology UFSC); Maria Luiza Goulart (participant/ Phonoaudiology UFSC); Milena Júlia Noll (participant/ Phonoaudiology UFSC); Júlio Moreira (participant/ Phonoaudiology UFSC); Daline Dalet; Júlio Moreira (participant/ Phonoaudiology UFSC)

Partners: Foundation for Research and Innovation Support of the State of Santa Catarina (Fundação de Amparo à Pesquisa e Inovação do Estado de Santa Catarina – FAPEU); Secretary of State for Health; InCOD; Florianópolis City Hall.

Project images: