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Andi Petculescu

Research

My research focus is in physical acoustics combining experimental, theoretical, and computational work. Recent applications include planetary science, fluid property sensing, and acoustic beamforming.

Find out more on my website; for up-to-date information on reseach projects and papers go to my Academia and Research Gate profiles.

Current projects

  • Atmospheric acoustics on Mars, Venus, and Titan.  [link1] [link2]
  • Wind noise predictions in porous-dome filters for infrasound sensing on Mars. [link]
  • Attenuation of low-frequency acoustic waves through the main clouds of Venus. [link]
  • Absorption and dispersion of infrasound in Earth's lower thermosphere. [link]
  • Speech enhancement in noisy reverberant rooms using adaptive beamforming with dense microphone arrays. [link]
  • Quantitative Acoustic Relaxation Spectroscopy (QARS) for real-time monitoring of gas proceeses. [link1] [link2]

 

Active-research nuggets

  • Acoustic wave motion in Venus’s deep atmosphere. (theoretical/computational)
    • Calculate the acoustic wavenumber in the first 10 km of Venus’s atmosphere, under conditions of
  • Seismoacoustic coupling on Venus. (theoretical/computational)
    • Assess the efficiency of venusquakes and volcanoes to generate infrasound signals in the supercritical deep atmosphere. Theoretical/computational modeling of the first few km of Venus's atmosphere using real-gas equations of state appropriate for supercritical conditions.
  • Remote detection of seismic events on Venus by infrasonic sensing in the upper troposphere. (theoretical/computational).
    • Infrasound absorption and dispersion through the clouds of Venus. Goal: develop a framework for using infrasonic arrivals to quantify seismic activity on Venus by balloons drifting at 55 km.
  • Infrasonic wind-noise inside porous dome structures. (theoretical)
    • Calculate the non-acoustic contributions to the fluctuating pressure at the center of porous domes, arising from turbulent interactions. Goal: investigate the use of porous domes as wind-noise filters alternatives for infrasound sesning in the extreme environment of Mars.
  • Infrasonic absorption in Earth’s lower thermosphere. (theoretical/computational)
    • Develop a model for infrasound absorption and dispersion in Earth’s upper mesosphere/lower thermosphere (UMLT). Goals: 1) improve prediction accuracy for thermospheric arrivals; 2) investigate using long-range infrasonic signals to study UMLT dynamics (especially winds).
  • Predicting thunder on Earth and Titan. (theoretical/computational)
    • Understand the generation and propagation of thunder, combining microscale lightning thermochemistry, shockwave theory, and nonlinear ray-tracing. Goals: 1) improve thunder models to better understand lightning discharges, 2) assess the feasibility to use thunder sensing as a tool to quantify lightning on Titan.
  • Adaptive beamforming. (experimental)
    • Develop beamforming algorithms in the time-frequency domain, based on measured impulse responses. Goal: seek efficient techniques to localize moving sources and enhance signals in reverberant and/or noisy environments.
  • Acoustics of granular media. (experimental)
    • Measure the minute energy lost as audible sound during collisions of small solid spheres and bring small corrections to Hertz’s contact law. Study sound propagation in granular media, focusing on the onset of jamming.
  • Quantitative Acoustic Relaxational Spectroscopy. (experimental, theoretical, computational)
    • Develop ultrasonic techniques for fast and robust monitoring of gas flow processes. A potential approach being investigated relies on extrapolating the dynamic specific heat of the gaseous mixture by speed and attenuation measurements at only a few frequencies.

Representative papers

M. Gillier, A. Petculescu et al., “Geographical, seasonal and diurnal variations of acoustic attenuation and sound speed in the near-surface Martian atmosphere,” Journal of Geophysical Research: Planets, DOI: 10.1029/2023JE008257 (2024)
B. Chide, X. Jacob, A. Petculescu et al., “Measurements of sound propagation in Mars’ lower atmosphere,” Earth Planet. Sci. Lett. 615 118200 , DOI: 10.1016/j.epsl.2023.118200 (2023)
G. Averbuch, R. Houston, and A. Petculescu, ``Seismo-acoustic coupling in the deep atmosphere of Venus,'' J. Acoust. Soc. Am. 153 1802-1810 (2023)
A. J. Trahan and A. Petculescu, ``Absorption of Infrasound in the Lower and Middle Clouds of Venus,'' J. Acoust. Soc. Am. 148 141-152 (2020)
K. Pitre and A. Petculescu, ``Porous domes as wind-noise filters for infrasound sensing on Mars," Planetary and Space Science 167 33-41 (2019).
A. Petculescu, ``Acoustic properties in the low and middle atmospheres of Mars and Venus,'' J. Acoust. Soc. Am. 140 1439-1446 (2016).
T. G. Leighton and A. Petculescu, ``Guest Editorial: Acoustic and Related Waves in Extraterrestrial Environments,'' J. Acoust. Soc. Am. 140 1397-1399 (2016).
A. Petculescu and R. Kruse, ``Predicting the characteristics of thunder on Titan: A framework to assess the detectability of lightning by acoustic sensing,'' J. Geophys. Res. Planets 119 2167-2176 (2014).
A. Akintunde and A. Petculescu, ``Infrasonic attenuation in the upper mesosphere-lower thermosphere: A comparison between Navier-Stokes and Burnett predictions,'' J. Acoust. Soc. Am. 136 1483 (2014).
A. C. Raga, J. Canto, A. Rodriguez-Gonzalez, and A. Petculescu, ``The strong/weak shock transition in cylindrical and planar blast waves ,'' Rev. Mex. Astron. Astrofisica 50 145-150 (2014).
A. Petculescu and P. Achi, ``A model for the vertical sound speed and absorption profiles in Titan's atmosphere based on Cassini-Huygens data,'' J. Acoust. Soc. Am. 131 3671-3679 (2012).
A. Petculescu and R. M. Lueptow, ``Quantitative acoustic relaxational spectroscopy for real-time monitoring of natural gas: a perspective on its potential,'' Sensors and Actuators B: Chemical 169 121-127 (2012).
A. Petculescu and J. Riner, ``Constraining the minute amount of audible energy radiated from binary collisions of light plastic spheres in conditions of incomplete angular coverage of the measured pressure,'' J. Acoust. Soc. Am. 128 1575-1577 (2010).
A. Petculescu and R. M. Lueptow, ``Non-Hertzian behavior in binary collisions of plastic balls derived from impact acoustics,'' J. Acoust. Soc. Am. 128 132-136 (2010).
A. Petculescu and R. M. Lueptow, ``Atmospheric acoustics of Titan, Mars, Venus, and Earth,'' Icarus 186 413-419 (2007).
A. Petculescu and R. M. Lueptow, ``A prototype acoustic gas sensor based on attenuation,'' J. Acoust. Soc. Am. 120 1779-1782 (2006).
A. Petculescu, ``Future trends in acoustic gas monitoring and sensing,'' J. Optoelec. Adv. Mat. 8 217-221 (2006).
A. Petculescu and R. M. Lueptow, ``Synthesizing Primary Molecular Relaxation Processes in Excitable Gases Using a Two-Frequency Reconstructive Algorithm,'' Phys. Rev. Lett. 94 238301 (2005). [Note: this lays out the basics of Quantitative Acoustic Relaxational Spectroscopy or QARS]
A. Petculescu and R. M. Lueptow, ``Fine-tuning molecular acoustic models: Sensitivity of the predicted attenuation to the Lennard-Jones parameters,'' J. Acoust. Soc. Am. 117 175-184 (2005).
A. Petculescu and J. Sabatier, ``Air-coupled ultrasonic sensing of grass-covered vibrating surfaces; qualitative comparisons with laser Doppler vibrometry,'' J. Acoust. Soc. Am. 115 1557-1564 (2004).
A. Petculescu and J. Sabatier, ``Signal-to-noise ratio improvement by sideband intermixing: Application to Doppler ultrasound vibrometry,'' Rev. Sci. Instrum. 74 4191-4193 (2003).
A. Petculescu and L. A. Wilen, ``Oscillatory flow in jet pumps: Nonlinear effects and minor losses,'' J. Acoust. Soc. Am. 113 1282-1292 (2003).
A. Petculescu and L. A. Wilen, ``Lumped-element technique for the measurement of complex density,'' J. Acoust. Soc. Am. 110 1950-1957 (2001).
 

Theses

Akinjide Akintunde (2014)

Caleb O'connor (2015)

Kevin Pitre (2016)

Adam Trahan (2018)

Peter Achi (2018)

Teaching

  • PHYS 207: Algebra-Based Introductory Physics
  • PHYS 324/424: Electricity and Magnetism I, II
  • PHYS 437/438: Quantum Mechanics I, II
  • PHYS 405: Thermodynamics and Statistical Physics
  • PHYS 460: Quantum Computing
    • This new course addresses the fundamentals of quantum computing, such as entanglement, multi-qubit states, quantum gates and circuits, quantum key distribution, dense coding and teleportation, the Quantum Fourier Transform, quantum parallelism, decoherence and quantum dissipation.
  • PHYS 521: Room Acoustics
    • The main aspects of room acoustics, including modal/statistical theory, reverberant fields, the physics of acoustic absorbers and other wall treatments, transmission through porous plates, as well as elements of concert-hall and classroom acoustics.
  • PHYS 523: Theoretical Acoustics
    • This course develops the theory of physical acoustics from the full Navier-Stokes-Fourier framework. Among the topics covered are energy losses in the bulk and at boundaries, non-classical absorption in polyatomic gases, sound radiation, reflection, transmission, and scattering, atmospheric acoustic sensing, and sound generation by turbulence.
  • PHYS 560: Fluid Mechanics
    • Kinematics and dynamics of fluid flow. Among the topics covered are viscous and thermal effects, diffusion, boundary layers, turbulence etc, with applications to pipe flow, turbomachinery, aerodynamics, and planetary atmospheres.
  • EESC 642: Atmospheric Physics
    • The physics of planetary atmospheres, including radiative and convective transfer, cloud formation, atmospheric circulation, and waves. The atmospheric characteristics of various planets are analyzed and compared throughout the course. Homework includes theoretical problems as well as analyzing data from NASA/NOAA/ESA.

Lecture notes

PHYS 437 Quantum Mechanics 1

PHYS 438 Quantum Mechanics 2

PHYS 523 Theoretical Acoustics