A robust physics-based method to filter coherent wavepackets from high-speed schlieren images

  title={A robust physics-based method to filter coherent wavepackets from high-speed schlieren images},
  author={Chitrarth Prasad and Datta V. Gaitonde},
  journal={Journal of Fluid Mechanics},
Abstract A complete understanding of jet dynamics is greatly enabled by the accurate separation of acoustically efficient wavepackets from their higher-energy convecting turbulent counterparts. Momentum potential theory (MPT) has proven highly effective in filtering the desired acoustic component irrespective of operating conditions or nozzle complexity. However, MPT is a data-intensive method predicated on the knowledge of fluctuation quantities in the entire flow field; as such, it has to… 


Transfer mechanisms from stochastic turbulence to organized acoustic radiation in a supersonic jet
Spectral analysis of jet turbulence
Informed by large-eddy simulation (LES) data and resolvent analysis of the mean flow, we examine the structure of turbulence in jets in the subsonic, transonic and supersonic regimes. Spectral
The proper orthogonal decomposition of pressure fluctuations surrounding a turbulent jet
It is shown that the pressure signal measured at the outer edge of a jet mixing layer is entirely hydrodynamic in nature and provides a good measure of the large-scale structure of the turbulent
Acoustic, hydrodynamic and thermal modes in a supersonic cold jet
Large-eddy simulation data for a Mach 1.3 round jet are decomposed into acoustic, hydrodynamic and thermal components using Doak’s momentum potential theory. The decomposed fields are then analysed
Wavelet analysis of near-field pressure fluctuations generated by a subsonic jet
Abstract An experimental study of the pressure field generated by a subsonic, single stream, round jet is presented. The investigation is conducted in the near-field region at subsonic Mach numbers
Wave Packets and Turbulent Jet Noise
Turbulent jet noise is a controversial fluid mechanical puzzle that has amused and bewildered researchers for more than half a century. Whereas numerical simulations are now capable of simultaneously
Mach Wave Radiation from High-Speed Jets
Extensive experimental evidence is now available to support the observation that there are two components of jet mixing noise. They are the fine-scale turbulence noise and the noise from the large
Experimental Investigation of Near-Field Pressure Fluctuations Generated by Supersonic Jets
This paper describes an experimental investigation of near-field pressure fluctuations generated by round supersonic jets. Previous investigations have shown that there are two pressure components
Images constructed from computed flowfields
A method for constructing interferograms, schlieren, and shadowgraphs from ideal- and real-gas, two- and three-dimensional computed flowfields is described. The computational grids can be structured
The near pressure field of co-axial subsonic jets
Results are presented from pressure measurements performed in the irrotational near field of unbounded co-axial jets. Measurements were made for a variety of velocity and temperature ratios, and