Hasil untuk "Acoustics in engineering. Acoustical engineering"

De Carvalho Davide, Billot Guido, Marinus Benoît G. et al.

Outdoor noise measurement is highly uncertain due to its strong dependence on environmental conditions. In firearm noise studies, these uncertainties are amplified by the impulsive nature of the noise and the lack of large datasets, making long-term meteorological averaging and stochastic techniques impractical. Numerical models also face limitations, with most commercial software relying on coefficient-based environmental predictions. This study investigates uncertainties and environmental effects in outdoor firearm noise propagation, combining experimental and numerical approaches to understand their impacts. The expanded uncertainty of systematic (Type B) uncertainties contribute up to ±4.1 [dB], while random (Type A) uncertainties, influenced by environmental variability, range from ±0.5 to ±10 [dB], predominantly affecting mid- to high-frequency bands at extended distances. A refined 2D Nonlinear Progressive Equation (NPE) model is used to simulate varying terrains and atmospheric conditions. Results reveal that sound-dampening terrains, such as grass, cause significant amplitude and spectral shifts compared to asphalt, with attenuations up to 10 [dB] at specific frequencies and distances. Downwind conditions enhance high-frequency propagation, while upwind scenarios reduce signal strength, with notable effects indicatively happening beyond 65 [m]. The findings highlight the importance of environmental characterization and advanced modeling as complementary tools for understanding and contextualizing uncertainties in firearm noise studies, supporting the development of improved methodologies for military and civilian acoustic applications.

Xiao Xiao, Yang Jing, Harris Michael S. et al.

The present study examined the influence of changes in speakers’ fundamental frequency (fo) and vocal tract resonance (VTR) on speech recognition in different types of noise by non-native listeners. The goal was to identify whether the fo-VTR relationship has a similar effect on non-native listeners as it does on native listeners. Twenty-six adults who were native Mandarin speakers learning English as a second language were presented with English Hearing-in-Noise Test (HINT) sentences in four voice conditions with the original male speaker's fo doubled and/or VTR scaled up by a factor of 1.2: (1) low fo low VTR (LfoLVTR, the original recordings); (2) low fo high VTR (LfoHVTR); (3) high fo high VTR (HfoHVTR), and (4) high fo low VTR (HfoLVTR). The stimuli were presented in speech-shaped noise (SSN) and four-talker babble (FTB) at signal-to-noise ratios of −3, 0, +3 dB. The results showed that the non-native listeners performed more poorly with fo-VTR mismatched voices than with fo-VTR matched voices and the negative influence of mismatched voice features was mainly manifested in the HfoLVTR condition. Compared to SSN, FTB had a greater adverse impact on the non-native listeners’ recognition accuracy. Further, the performance difference between matched and mismatched conditions showed distinct patterns across SSN and FTB.

Salvador-Castrillo Víctor, Picard Amélie, Spalletta Duilio et al.

The goal of this study is to investigate the perception of different bow mass distributions using an experimental violin bow. The position of the centre of mass and the moment of inertia were independently modified through five distinct mass configurations, which were tested by multiple violinists. Various perceptual tests, including three discrimination tests and a free evaluation test, were conducted. Concepts from Signal Detection Theory were used to calculate a representative sensitivity value, considering participants’ sureness in their responses to discrimination tests. Results indicate that participants were sensitive to a substantial variation (10%) in the position of the centre of mass when holding the bow in the air versus during playing, though they did not seem to perceive minor changes (4%) significantly. Conversely, participants exhibited sensitivity to both minor (4%) and substantial (12%) variations in the moment of inertia while playing, suggesting a heightened awareness of even slight modifications in this parameter. Furthermore, the free evaluation test revealed that the perceived bow weight was influenced by both parameters, while the quality of bouncing bow strokes appeared to be more influenced by the moment of inertia.

Soares Filipe, Cochelin Bruno, Freour Vincent et al.

The modelling approach presented here aims at developing accurate, yet computationally efficient, numerical models of brass instrument resonators including nonlinear propagation, viscothermal losses and radiation effects in 2D axisymmetric domains. The central idea is to bridge the refined accuracy of 2D models with the efficiency of reduced-order modal approaches. To model the nonlinear acoustic propagation inside the resonator, we propose the use of the Blackstock equation, a more appropriate choice when dealing with nonlinear standing wave motion, compared to the more commonly used Burgers equation. The first step of the approach consists in obtaining a complex modal basis from a 2D axisymmetric finite element model of the linearized equations. Here, a bounded domain outside the resonator, with a nonreflecting boundary condition, is included to explicitly account for 2D radiation effects. Moreover, the effects of the viscothermal boundary layers at the interior walls are modelled efficiently through an impedance boundary condition. The Blackstock equation is then projected onto the resulting 2D complex modal basis, leading to a compact set of nonlinear ordinary differential equations (ODEs) that can be truncated at any suitable number of terms. This leads to exploitable reduced formulations, adapted to quick temporal simulations, bifurcation analysis or parametric studies, retaining nevertheless the accuracy provided by 2D axisymmetric models. Additionally, the explicit account of the exterior acoustic field allows for the calculation of radiated sound pressures as well as directivity patterns, contrary to typical 1D models. Experimental validation and illustrative numerical results are presented for a simplified trumpet geometry in both linear and nonlinear scenarios, highlighting the benefits of the proposed approach.

Tim Wittenborg, Ildar Baimuratov, Ludvig Knöös Franzén et al.

The aerospace industry operates at the frontier of technological innovation while maintaining high standards regarding safety and reliability. In this environment, with an enormous potential for re-use and adaptation of existing solutions and methods, Knowledge-Based Engineering (KBE) has been applied for decades. The objective of this study is to identify and examine state-of-the-art knowledge management practices in the field of aerospace engineering. Our contributions include: 1) A SWARM-SLR of over 1,000 articles with qualitative analysis of 164 selected articles, supported by two aerospace engineering domain expert surveys. 2) A knowledge graph of over 700 knowledge-based aerospace engineering processes, software, and data, formalized in the interoperable Web Ontology Language (OWL) and mapped to Wikidata entries where possible. The knowledge graph is represented on the Open Research Knowledge Graph (ORKG), and an aerospace Wikibase, for reuse and continuation of structuring aerospace engineering knowledge exchange. 3) Our resulting intermediate and final artifacts of the knowledge synthesis, available as a Zenodo dataset. This review sets a precedent for structured, semantic-based approaches to managing aerospace engineering knowledge. By advancing these principles, research, and industry can achieve more efficient design processes, enhanced collaboration, and a stronger commitment to sustainable aviation.

Nasir U. Eisty, Jeffrey C. Carver, Johanna Cohoon et al.

In the evolving landscape of scientific and scholarly research, effective collaboration between Research Software Engineers (RSEs) and Software Engineering Researchers (SERs) is pivotal for advancing innovation and ensuring the integrity of computational methodologies. This paper presents ten strategic guidelines aimed at fostering productive partnerships between these two distinct yet complementary communities. The guidelines emphasize the importance of recognizing and respecting the cultural and operational differences between RSEs and SERs, proactively initiating and nurturing collaborations, and engaging within each other's professional environments. They advocate for identifying shared challenges, maintaining openness to emerging problems, ensuring mutual benefits, and serving as advocates for one another. Additionally, the guidelines highlight the necessity of vigilance in monitoring collaboration dynamics, securing institutional support, and defining clear, shared objectives. By adhering to these principles, RSEs and SERs can build synergistic relationships that enhance the quality and impact of research outcomes.

Oz Levy, Ilya Dikman, Natan Levy et al.

This paper explores how generative AI can help automate and improve key steps in systems engineering. It examines AI's ability to analyze system requirements based on INCOSE's "good requirement" criteria, identifying well-formed and poorly written requirements. The AI does not just classify requirements but also explains why some do not meet the standards. By comparing AI assessments with those of experienced engineers, the study evaluates the accuracy and reliability of AI in identifying quality issues. Additionally, it explores AI's ability to classify functional and non-functional requirements and generate test specifications based on these classifications. Through both quantitative and qualitative analysis, the research aims to assess AI's potential to streamline engineering processes and improve learning outcomes. It also highlights the challenges and limitations of AI, ensuring its safe and ethical use in professional and academic settings.

Lekshmi Murali Rani

The study of behavioral and social dimensions of software engineering (SE) tasks characterizes behavioral software engineering (BSE);however, the increasing significance of human-AI collaboration (HAIC) brings new directions in BSE by presenting new challenges and opportunities. This PhD research focuses on decision-making (DM) for SE tasks and collaboration within human-AI teams, aiming to promote responsible software engineering through a cognitive partnership between humans and AI. The goal of the research is to identify the challenges and nuances in HAIC from a cognitive perspective, design and optimize collaboration/partnership (human-AI team) that enhance collective intelligence and promote better, responsible DM in SE through human-centered approaches. The research addresses HAIC and its impact on individual, team, and organizational level aspects of BSE.

Max Neuwinger, Dirk Riehle

The design of effective programming languages, libraries, frameworks, tools, and platforms for data engineering strongly depends on their ease and correctness of use. Anyone who ignores that it is humans who use these tools risks building tools that are useless, or worse, harmful. To ensure our data engineering tools are based on solid foundations, we performed a systematic review of common programming mistakes in data engineering. We focus on programming beginners (students) by analyzing both the limited literature specific to data engineering mistakes and general programming mistakes in languages commonly used in data engineering (Python, SQL, Java). Through analysis of 21 publications spanning from 2003 to 2024, we synthesized these complementary sources into a comprehensive classification that captures both general programming challenges and domain-specific data engineering mistakes. This classification provides an empirical foundation for future tool development and educational strategies. We believe our systematic categorization will help researchers, practitioners, and educators better understand and address the challenges faced by novice data engineers.

Kirsch Christoph, Ewert Stephan D.

Geometrical acoustics (GA) offers a high computational efficiency, as required for real-time renderings of complex acoustic environments with applications in, e.g., hearing research, architectural planning, and entertainment. However, the assumed ray-like sound propagation does not account for perceptually relevant effects of diffraction. In indoor environments, diffraction at finite objects and apertures such as tables, music stands, and doors is of interest for computationally efficient rendering. Outdoors, buildings and barriers are relevant. Here, we extend the recent physically-based universal diffraction filter approximation (UDFA) for GA to approximate spectral effects of higher-order diffraction and apply it to a flat finite object and a double edge. At low frequencies, such effects predominantly occur when sound is diffracted repeatedly at the edges of a finite object, and at high frequencies when sound is propagating around subsequent edges of, e.g., buildings or sound barriers. In contrast to existing methods, the suggested filter approaches and topology offer spatially smooth infinite impulse response implementation for modelling higher-order diffraction at flat objects for arbitrary geometrical arrangements. For double diffraction at a three-sided barrier, errors are considerably decreased in comparison to a state-of-the-art sequential approach. Both suggested methods are computationally highly efficient and scalable depending on the desired accuracy.

Kayser Bill, Dragna Didier, Blanc-Benon Philippe

A coupled approach is proposed for predicting sound radiation from a monopole in arbitrary motion in a moving and inhomogeneous atmosphere. It is based on a heuristic model proposed in the literature for sound radiation by a moving source in a homogeneous atmosphere at rest above an absorbing ground and a ray-tracing code, which takes into account meteorological effects. Validation of the model is performed with a reference three-dimensional finite-difference time-domain solution of the linearized Euler equations for several test-cases with different source trajectories and atmospheric conditions. We show that neglecting convective amplification or the source motion between the emission and reception times can lead to significant errors in the predictions. Finally, an application case for aircraft noise is presented. The importance of ground and meteorological effects on the sound pressure levels is highlighted.

Auquier Nicolas, Ege Kerem, Gourdon Emmanuel

The research presented in this paper aims to demonstrate how imperfect interfaces influence the behavior of a multilayered structure. To achieve this, a dynamic equivalent model for multilayered panels is used, enabling the characterization of these interfaces using experimental data. This model, known as the Layer Wise (LW) model, incorporates imperfections in the interfaces through sliding displacement. To effectively validate the model against experimental measurements, an equivalence with a thin beam is established. Then the experimental methodology used for characterization is outlined, including the setup, considered samples, and data processing techniques. Specifically, the Corrected Force Analysis Technique (CFAT) is used, which is a robust method based on the equations of motion for thin plates or beams. This method, for the first time, allows obtaining broadband frequency results, facilitating dynamic monitoring of interface states in multilayers. The concurrently developed model enables the quantification of an interface parameter through experimental measurements. Finally, a detailed analysis of the results obtained through this methodology is provided, emphasizing the significant influence of imperfect interfaces on the dynamics of multilayered structures.

Somma Antonio, Roudet Jeanne, Fabre Benoît

The conventional methods used to measure and model the dynamics of a piano keystroke typically involve applying force at the key front using mechanical excitation. However, the influence of the actuator mass on the resulting motion and force profile has never been addressed. Conversely, within the realm of piano technique, mechanical excitation occurs through engagement with parts of the pianist’s body, whose mass can vary significantly. Pianists claim to have the ability to adjust the mass they engage at will. We propose a new approach that integrates the pianists’ bodily presence into the mechanical system under examination. By doing so, we aim to reformulate the control parameters associated with piano keystrokes, as typically discussed in scientific literature. This approach yields a simplified model of a pressed keystroke that incorporates the presence of an actuator mass. Through minimally invasive experiments, we observe the relationship between tone volume and driving force, considering levels of inertia comparable to those engaged by pianists through their bodies, with excitation starting at the surface of the key. The results are consistent with our proposed model, highlighting the antagonistic role of total inertia in piano tone production. This approach broadens our understanding of pianists’ control strategies and sheds light on its complex interplay with musical needs in piano performance.

Adrian Bajraktari, Michelle Binder, Andreas Vogelsang

Modern science is relying on software more than ever. The behavior and outcomes of this software shape the scientific and public discourse on important topics like climate change, economic growth, or the spread of infections. Most researchers creating software for scientific purposes are not trained in Software Engineering. As a consequence, research software is often developed ad hoc without following stringent processes. With this paper, we want to characterize research software as a new application domain that needs attention from the Requirements Engineering community. We conducted an exploratory study based on 8 interviews with 12 researchers who develop software. We describe how researchers elicit, document, and analyze requirements for research software and what processes they follow. From this, we derive specific challenges and describe a vision of Requirements Engineering for research software.

D. Wilson

Computational acoustics is in its second full year as a Technical Committee, after being promoted from a Technical Specialty Group in May 2022. The CA TC provides a forum for researchers interested in numerical methods pertinent to acoustic wave propagation and structures, data analytics, validation, optimization, visualization, as well as application of computational models to engineering, noise control, and other practical problems. Some areas of current and emerging interest include artificial intelligence, uncertainty characterization, model reduction techniques, efficient parallelization, and time-domain treatments of dissipation. The CA TC is also interested in building collaborations with other TCs on repositories and benchmarks for codes and data.

David A. Brown, John R. Buck, P. Gendron

The University of Massachusetts Dartmouth has a long history spanning 5 decades of graduate courses offerings and research in underwater acoustics, transduction and signal processing leading to M.S. and Ph.D. degrees in Electrical Engineering. Collaborations between Marine Science, Physics, Mechanical, Bioengineering, and Electrical Engineering departments offer many interdisciplinary opportunities in Acoustics. Courses include Fundamentals of Acoustics, Vibrations, Underwater Acoustics, Electroacoustic Transducers, Medical Ultrasonics, Sonar, Digital Signal Processing, Array Processing, Random Signals, Information Theory, Communications, Detection and Estimation. Many unique facilities including an Underwater Acoustic Test Tank, Open-Ocean water access, and Unmanned Underwater Vehicles support both undergraduate and graduate projects. Research focuses include transducers and transduction science, materials characterization, calibration, array and sonar signal processing, animal bioacoustics, communications, detection and estimation, active and passive sonar funded by Office of Naval Research and Industry.

F. A. Machuca-Tzili, A. Padilla-Ortiz, Daniel Martínez-Gutiérrez

A clear comprehension of the oscillatory nature of sound for acoustics undergraduate students is of paramount importance. In this paper, two online experiments were implemented to aid teaching of the oscillatory nature of sound through the analogy between a mechanical mass-spring model and a Helmholtz resonator. The study was conducted among undergraduate students taking a science course in the Electronic and Electrical Engineering career curriculum. These in-class experiments were conducted during the COVID-19 pandemic via the Zoom platform. Students measured the Helmholtz resonant frequency of a plastic bottle with a smartphone application and compared its oscillatory behavior with that of a conventional harmonic oscillator under a professor-student collaborative environment. The results of this study suggest that, with careful experiment design, students can effectively benefit from the use of common technology tools, which, in turn, poses these methodologies as a rather satisfactory alternative to face-to-face laboratory sessions.

Geyer Thomas F., Enghardt Lars

The advent of electrified propulsion systems for civil aircraft promises not only notable reductions of CO2 and NOx emissions, but also of perceived noise. In an attempt to estimate the noise reduction potential of fully electric aircraft engines, the current study compares the noise generated by classical turboprop and turbofan engines with noise spectra calculated for electrified engines. The calculation is based on published far-field sound pressure level spectra at different noise certification points, which are then modified to account for the absence of combustion-related noise sources. In addition to the overall sound pressure level, changes to the effective perceived noise level are also taken into account. The results clearly show that the electrification of the engine alone will not lead to the notable noise reductions that are required in order to achieve the goals for future aviation set by the European Commission. Instead, continued research is necessary to further reduce noise sources that will continue to be present in novel electrified aircraft systems, such as fan noise and airframe noise.

Kayser Bill, Écotière David, Gauvreau Benoit

This paper investigates the influence of atmospheric turbulence on the propagation of wind turbine noise using an aeroacoustic source model coupled with a parabolic equation propagation model. Sets of simulations with and without atmospheric turbulence are performed, allowing the determination of a simple formulation that quantifies the uncertainties of the A-weighted sound pressure level (SPL) when the modelling does not account for atmospheric turbulence. For the case study, the results show that atmospheric turbulence has a negligible effect on SPL up to 800 m from the wind turbine, even under upwind conditions. While the conclusions are specific to this case study, the method appears promising for simplifying the calculation of atmospheric turbulence effect in wind turbine noise studies. A freely accessible online application has been developed to present additional results.

Silitonga Dicky J., Declercq Nico F.

Compared to standard plain glass panes, laminated glass has many advantages, such as improved glass panes’ safety, structural strength, and aesthetics. An essential quality criterium of laminated glass, tunable during production, is the adhesion strength of the interlayer. Traditional quality control is destructive and involves peeling, tensioning, or impacting the specimens, while ultrasound may, if properly applied, reveal the quality parameters nondestructively and reduce production costs. In facilities equipped with ultrasonic phased array transducers, bounded beam effects may be exploited to investigate the considered glass panels. In this work, we provide a proof of concept of a bounded beam effect, known as the Schoch displacement, caused by ultrasonic guided waves, to map variations in adhesion nondestructively. Even though in industrial production lines, one may opt for phased array techniques to measure the effects, in this work, we provide images obtained by acousto-optic Schlieren photography for demonstrative purposes.