Near field screech noise computation for an underexpanded supersonic jet by the CE/SE method

Loh, Ching Y.; Hultgren, Lennart S.; Jorgenson, Philip C. E.

doi:10.2514/6.2001-2252

Cited by 30 publications

(35 citation statements)

References 14 publications

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“…As demonstrated in our previous papers, the CE/SE scheme is well suited for aeroacoustics computation [9,10]. Because of the CE/SE non-reflecting boundary conditions (NRBC), which are based on flux balance [11], a smaller near field computational domain can be used in the present numerical simulation and helps to save both memory and CPU time.…”

Section: Introductionmentioning

confidence: 97%

Near Field Trailing Edge Tone Noise Computation

Loh

2003

41st Aerospace Sciences Meeting and Exhibit

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Blunt trailing edges in a flow often generate tone noise due to wall-jet shear layer and vortex shedding. In this paper, the spacetime conservation element and solution element (CE/SE) method is employed to numerically study the near-field noise of blunt trailing edges. Two typical cases, namely, flow past a circular cylinder (aeolian noise problem ) and flow past a flat plate of finite thickness are considered. The computed frequencies and the estimated sound pressure level (SPL) compare well with experimental data. For the aeolian noise problem, comparisons with the results of other numerical approaches are also presented.

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Section: Introductionmentioning

confidence: 97%

Near Field Trailing Edge Tone Noise Computation

Loh

2003

41st Aerospace Sciences Meeting and Exhibit

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“…to the A2-mode screech tone observed in Panda's [9] experiment. Note that in our previous work [5], which had a much simplified description of the nozzle external geometry, the Al-mode screech tone (not observed in [9]) was also obtained at this condition.…”

Section: D-254mentioning

confidence: 99%

Computing Jet Screech: A Complex Aeroacoustic Feedback System

Loh¹,

Hultgren²

2003

Computational Fluid Dynamics 2002

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“…To serve as a preliminary for future development, here we shall briefly review an extension of the c scheme which was introduced as a remedy for this deficiency [3,35].…”

Section: The A-scheme and The C Schemementioning

confidence: 99%

Courant Number and Mach Number Insensitive CE/SE Euler Solvers

Chang¹

2005

41st AIAA/ASME/SAE/ASEE Joint Propulsion Conference &Amp;amp; Exhibit

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IntrodutionThe space-time conservation element and solution element (CE/SE) method is a high-resolution and genuinely multidimensional method for solving conservation laws . Its nontraditional features include: (i) a unified treatment of space and time; (ii) the introduction of conservation elements (CEs) and solution elements (SEs) as the vehicles for enforcing space-time flux conservation; (iii) a novel time marching strategy that has a space-time staggered stencil at its core and, as such, fluxes at an interface can be evaluated without using any interpolation or extrapolation procedure (which, in turn, leads to the method's ability to capture shocks without using Riemann solvers); (iv) the requirement that each scheme be built from a non-dissipative core scheme and, as a result, the numerical dissipation can be controlled effectively; and (v) the fact that mesh values of the physical dependent variables and their spatial derivatives are considered as independent marching variables to be solve for simultaneously. Note that CEs are nonoverlapping space-time subdomains introduced such that (i) the computational domain can be filled by these subdomains; and (ii) flux conservation can be enforced over each of them and also over the union of any combination of them. On the other hand, SEs are space-time subdomains introduced such that (i) the boundary of each CE can be divided into several component parts with each of them belonging to a unique SE; and (ii) within a SE, any physical flux vector is approximated using simple smooth functions. In general, a CE does not coincide with a SE.Without using flux-splitting or other special techniques, since its inception [1] the unstructured-mesh compatible CE/SE method has been used to obtain numerous accurate 1D, 2D and 3D steady and unsteady flow solutions with Mach numbers ranging from 0.0028 to 10 [42]. The phyical phenomena modeled include traveling and interacting shocks, acoustic waves, shedding vortices, viscous flows, detonation waves, cavitation, flows in fluid film bearings, heat conduction with melting and/or freezing, electrodynamics, MHD vortex, hydraulic jump, crystal growth, and chromatographic problems . In particular, the rather unique capability of the CE/SE method to resolve both strong shocks and small disturbances (e.g., acoustic waves) simultaneously [11,13,14] makes it an effective tool for attacking computational aeroacoustics (CAA) problems. Note that the fact that second-order CE/SE schemes can solve CAA problems accurately is an exception to the commonly-held belief that a second-order scheme is not adequate for solving CAA problems. Also note that, while numerical dissipation is needed for shock capturing, it may also result in annihilation of small disturbances. Thus a solver that can handle both strong shocks and small disturbances simultaneously must be able to overcome this difficulty.In spite of its past successes, there is still room for improving the CE/SE method. An example is the fact that, in a CE/SE simulation with a fixed t...

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Near field screech noise computation for an underexpanded supersonic jet by the CE/SE method

Cited by 30 publications

References 14 publications

Near Field Trailing Edge Tone Noise Computation

Near Field Trailing Edge Tone Noise Computation

Computing Jet Screech: A Complex Aeroacoustic Feedback System

Courant Number and Mach Number Insensitive CE/SE Euler Solvers

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