High-Order Three-Dimensional Numerical Simulation of a Supersonic Rectangualr Jet

AlQadi, Ibraheem; Scott, James N.

doi:10.2514/6.2003-3238

Cited by 10 publications

(7 citation statements)

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“…The compressible LES strategy presented in this paper hence turns out to be a reliable tool to investigate the mechanisms underlying supersonic jet noise production. Even though there remains quantitative discrepancies as in previous studies due to the limitations of the simulations, [9][10][11] this numerical model has nonetheless been able to provide in-…”

Section: Discussionmentioning

confidence: 69%

“…Feasibility of DNC of subsonic jets using LES has been demonstrated, for instance, by Bogey and Bailly 6,7 and by Bodony and Lele. 8 As for LES of supersonic jet noise, Al Qadi and Scott 9 performed LES of a rectangular jet exhibiting screech tones, the shocks being captured using a highorder filter combined to a total variation diminishing ͑TVD͒ time integration scheme. Imamoglu and Balakumar 10 carried out the computation of a shock-containing circular jet using implicit LES based on weighted essentially nonoscillatory spatial discretization techniques, and on a TVD algorithm for time advancement.…”

Section: Introductionmentioning

confidence: 99%

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Numerical study of screech generation in a planar supersonic jet

2007

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The generation of screech tones in an underexpanded jet is investigated by means of compressible large eddy simulation ͑LES͒. A three-dimensional planar geometry is considered with the aim of studying screech radiation in a simple jet configuration, whose physics nevertheless remains similar to that of large-aspect-ratio rectangular jets encountered in experimental surveys. The jet operates at fully expanded Mach number M j = 1.55, with Reynolds number Re h =6ϫ 10 4. The LES strategy is based on explicit selective filtering with spectral-like resolution, and low-dispersion and low-dissipation numerical algorithms are implemented to allow the direct noise computation of the phenomenon. The numerical results are first set against experimental data to establish the consistency of the simulation. It is shown that the flow development and the shock-cell structure are in agreement with experiments of the literature. Furthermore, the upstream acoustic field exhibit harmonic tones that compare correctly to screech tones observed on rectangular jets in terms of frequency, amplitude, and phase shift on either side of the jet. The extrapolation of the LES near-field data to the far field demonstrates that the radiated noise includes the three characteristic noise sources of supersonic shock-containing jets: screech tones, shock-associated noise, and mixing noise, with frequencies and directivities in agreement with experimental observations. Flow visualization of shock/vortex interactions near the third shock-cell finally provides evidences that screech sound sources can be interpreted using the shock-leakage theory. It is shown in particular that the third compression shock within the jet can leak outside through regions of the shear layer with low level of vorticity and results in the production of upstream-propagating sound waves contributing to screech tone radiation.

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Section: Discussionmentioning

confidence: 69%

Section: Introductionmentioning

confidence: 99%

Numerical study of screech generation in a planar supersonic jet

2007

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“…With this aim in view, the effects of the presence of the nozzle lips in the computational domain have, for instance, been studied for subsonic jets at high Reynolds numbers by Bogey et al 10 and Uzun and Hussaini. 11 Screech noise generation has been studied numerically by Al-Qadi and Scott, 12 Berland et al, 13 and Li and Gao 14 in rectangular, planar, and round underexpanded supersonic jets. Simulations of the sound field obtained from beveled jet nozzles have been also performed by Paliath et al 15 and Viswanathan et al 16 Finally predictions of the noise generated by dual-stream jets have been carried out using LES by Andersson et al, 17 Vuillemin et al, 18 Mihăescu et al, 19 Viswanathan et al, 16 Tristanto et al, 20 and Eschricht et al 21 Dual-stream nozzles are of interest for the aerospace industry.…”

Section: Introductionmentioning

confidence: 99%

Simulation of a hot coaxial jet: Direct noise prediction and flow-acoustics correlations

et al. 2009

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A coaxial jet originating from parallel coplanar pipe nozzles is computed by a compressible large eddy simulation (LES) using low-dissipation and low-dispersion schemes in order to determine its acoustic field and to study noise generation mechanisms. The jet streams are at high velocities, the primary stream is heated, and the Reynolds number based on the primary velocity and the secondary diameter is around 106. High levels of turbulence intensity are also specified at the nozzle exit. The jet aerodynamic field and the near-pressure field are both obtained directly from the LES. The far-field noise is calculated by solving the linear acoustic equations, from the unsteady LES data on a cylindrical surface surrounding the jet. A good agreement is observed in terms of directivity, levels, and narrow-band spectra with noise measurements carried out during the EU project CoJeN for a coaxial jet displaying same stream velocities and temperatures, coplanar nozzle outlets with identical area ratio, and a high Reynolds number. However, certainly due to differences in the properties of the nozzle-exit boundary layers with respect to the experiment, some unexpected peaks are noticed in the simulation spectra. They are attributed to the development of a Von Kármán street in the inner mixing layer and to vortex pairings in the outer shear layer. High correlation levels are also calculated between the pressure waves radiated in the downstream direction and flow quantities such as axial velocity, vorticity norm, density, and temperature, taken around the end of the primary and secondary potential cores. Noise generation in the coaxial jet therefore appears significant around the end of the two potential cores. These flow regions are characterized by intermittency, a dominant Strouhal number, and variations in the convection velocity as similarly found in single jets. The use of density or temperature to compute flow-noise correlations finally seems appropriate for a heated jet flow, but might lead to correlations with acoustic disturbances in the potential core.

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“…In their 3-D computation, Shen and Tam [12] adopted a spectral method in the azimuthal direction and by using only a limited number of spectral functions achieved substantial savings of computer memory and CPU time, without deterioration of accuracy. Other recent computational work includes [19,20].…”

Section: Introductionmentioning

confidence: 99%