Center for Acoustics and Vibration


Technical Groups

The CAV is subdivided into several focus areas, including the following. Click on the links for each group to learn more about their missions and current research areas.

Member Database

You may now access our member database, including contact information and technical areas of interest. We hope this list is a useful resource for those who are interested in collaborating with CAV members on potential sponsored research projects.

Student thesis Database

We maintain a searchable database of Penn State PhD and MS theses in Acoustics and Vibration. You can find links to PDFs of most of the theses in the database. We will continue to add other theses as students graduate.

Technical Group Descriptions and Research Topics

Acoustic Materials and Metamaterials

acoustically cloaked object

The Acoustic Materials and Metamaterials technical group performs research in many areas involving the interaction between acoustics and materials. Not only can materials be used for acoustics and structural performance but acoustics can be used to evaluate material performance. Advances in traditional and additive manufacturing technologies can provide for unique acoustic and structural advantages. The underlying goal of this group is to continue to advance acoustic materials to evaluate new applications for acoustic and vibration control.

Research Topics

  • Material characterization
  • Manufacturing techniques for novel materials
  • Acoustic cloaking
  • Metamaterial inverse design
  • Active metamaterials
  • Structural vibration control through novel materials

Contact

Dr. Amanda Hanford, ald227@psu.edu, (814) 865-4528

Adaptive Structures and Noise Control

actively controlled flapping device

The mission of the Adaptive Structures and Noise Control Technical Group is to pursue strategies for reducing vibration and noise in engineering systems. This involves the development of accurate modeling approaches, passive control methods, discrete and distributed sensors and actuators as well as placement strategies, fast and stable adaptive control algorithms, and experiments to evaluate real-world performance. In complex mechanical/acoustical systems with multiple sensing and source/actuator locations, significant challenges remain.

Research Topics

  • Active damping using piezoelectric and other “smart” materials
  • Active mounts of for equipment and automobiles
  • Active, tunable vibration absorbers
  • Reduction of sound radiation with cancellation sources located in the vicinity of a primary radiator
  • Determination of optimal locations of cancellation sources to achieve either global or local noise reduction in small, low modal density enclosures, such as automobiles
  • Reduction of vibration and acoustic transmission from plates, elastically supported at multiple points on the foundation
  • Control of structural intensity to reduce the power flow of structural vibration in beams, plates, and complex structures
  • Energy harvesting from vibration and acoustic response

Contact

Dr. Jose Palacios, jlp324@psu.edu, (814) 867-4871

Biomedical Acoustics

ultrasound

The mission of the Biomedical Acoustics Technical Group is to understand and apply acoustic principles to biology with an overarching goal of improving human health.

Research Topics

  • Computational and experimental therapeutic ultrasound including high intensity focused ultrasound (HIFU)
  • Fourier acoustics (aka photoacoustics)
  • Elastography and shear wave imaging
  • Advanced image processing techniques
  • Mechanisms of acoustical-biological interactions

Contact

Dr. Julianna Simon, jcs516@engr.psu.edu, (814) 865-4417

Flow Induced Noise

Vortices shed from airfoil trailing edge

The focus of the Flow-Induced Noise Technical Group is the basic understanding and control of acoustic noise and structural vibration generated by fluid flow. The engineering challenges cover a very wide range of fluid/acoustic phenomena involving atmospheric acoustic media and the noise created by compressible fluid flow, as well as liquid acoustic media and the associated noise and vibration generated by essentially incompressible flows. Progress in developing models and supporting experimental data bases permits the description of possible noise control methods that can be evaluated analytically or numerically, and then with confidence, prototype apparati may be evaluated in the laboratory.

Research Topics

  • Wind/marine turbine noise
  • Noise radiation from non-circular and coaxial supersonic jets
  • Noise generated by intermittent, transitioning boundary layer flows on surfaces
  • Axial flow fan noise radiation and its control
  • Centrifugal pump and blower noise radiation and its control
  • Flow noise and structural response induced by turbulent flow
  • Bluff body flow noise
  • Computational aeroacoustics

Contact

Dr. Michael Jonson, mxj6@arl.psu.edu, (814) 863-3029

Propagation and Radiation

Microphone array

The mission of the Propagation and Radiation Technical Group is to develop a new understanding of how sound is generated and propagated in realistic environments, to translate this understanding into techniques for making decisions about the use and control of sound, and for making inferences about sources and the environment, and to apply this understanding to the design of devices and systems.

Research Topics

  • Sonic boom propagation through realistic atmospheric conditions and into the ocean
  • Using acoustic tomography through the oceans to measure global warming
  • Scattering of sound from structures with imprecisely known properties
  • Superposition techniques for the prediction of sound radiation from vibrating structures
  • Using acoustic tomography to inver micrometeorological features of the lower atmosphere
  • Scattering of sound from the bubble layer under the sea surface
  • Effects of seabed inhomogenenities on propagation in shallow water
  • Near-field acoustical holography
  • Computational methods in propagation and radiation

Contact

Dr. Vic Sparrow vws1@psu.edu, (814) 865-3162

Rotorcraft Acoustics and Dynamics

Drs. Smith and Horn in the cabin of the XV-15 Flight Simulator

The mission of the Rotorcraft Acoustics and Dynamics Technical Group is to conduct basic and applied research on technical problems of specific importance to rotary-wing vechicles such as helicopters and tiltrotor aircraft. Due to the highly multidisciplinary nature of rotorcraft systems, many of our projects involve research teams consisting of members from several different CAV technical groups. Current research thrusts and technical interests include analytical and experimental rotor aeroacoustics, cabin noise reduction, modeling and characterization of elastomeric materials, innovative applications of composite structures, advanced rotor design concepts, dynamics of shipborne rotorcraft, manufacturing technologies for dynamic components, and powertrain system technologies.

Research Topics

  • Analytical modeling and experimental characterization of elastomeric materials for helicopter rotor lag dampers
  • Tailored composite blades for enhanced aeromechanical stability, vibration reduction, and vehicle performance improvements
  • Modeling of transient rotor response in a shipboard airwake environment
  • Development of coupled aeroelastic/aeroacoustic analyses for advanced rotor systems
  • Concurrent design and manufacturing technologies for elastically tailored and adaptive composite blades
  • Thermomechanical finishing of precision gears for high performance, low noise, high strength helicopter transmission systems

Contact

Dr. Ed Smith, ecs5@psu.edu, (814) 863-0966

Structural Vibration and Acoustics

A diver conducts experimental modal analysis on a cylindrical shell submerged in water

The mission of the Structural Vibration and Acoustics Technical Group is to better understand the mechanisms of vibration generation and propagation in structures and the interaction of structural vibrations with acoustic media, and to develop novel methodologies for the analysis, measurement, and control of structural vibrations and radiated noise.

Research Topics

  • Structural vibration measurements, including experimental modal analysis, and simulations with finite element and boundary element modeling
  • Acoustic and structural intensity simulations and measurements, including the use of intensity as a structural health monitoring metric
  • Vibro-acoustics of composite structures, including Carbon Fiber Reinforced Plastics (CFRPs) and honeycomb core sandwich panels
  • Passive and active vibration and noise control technologies
  • Machinery and powertrain vibration and noise

Contact

Dr. Steve Hambric, sah19@psu.edu, (814) 863-3030

Systems and Structures Health Management

Typical prognostics plot

The mission of the Systems and Structures Health Management Technical Group is to develop new methodologies and technologies to manage the life cycle of systems and structures. This includes the full range of material state awareness, health and usage monitoring, and condition based maintenance, to support both autonomic and conventional operations with logistics informed by reliable useful life prediction. The underlying goal of the group is to maximize safety, minimize life cycle cost and increase capablity. Key areas being investigated inclue: senor systems, signal processing, pattern recognition, reasoning techniques, and modeling of damage progression to failure.

Research Topics

  • Nonlinear dynamics in water and mechanical failure
  • Approximate reasoning and data fusion
  • Bearing failure simulation and modeling
  • Improved sensors for failure precursor detection
  • Advanced materials for failure reporting
  • Modeling to relate failure mechanisms to observables
  • Gear system dynamic failure modeling
  • Active interrogation techniques for fault detection
  • Signal processing techniques for failure precursor detection and classification

Contact

Dr. Karl Reichard, kmr5@psu.edu, (814) 863-7681 or Dr. Cliff Lissenden, lissenden@psu.edu, (814) 863-5754