Comparison of PLIF and CFD Results for the Orion CEV RCS Jets

Ivey, Christopher B.; Danehy, Paul M.; Bathel, Brett F.; Dyakonov, Artem A.; Inman, Jennifer A.; Jones, Stephen B.

doi:10.2514/6.2011-713

Cited by 13 publications

(8 citation statements)

References 11 publications

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“…Furthermore, the measured NO PLIF signal is also sensitive to pressure and temperature variations, both of which can vary significantly in a compressible flow with shock and expansion features. Nevertheless, the current approach is similar to previous work of Fox et al, 13 and Gaston et al 14 The PLIF images computed from the CFD are referred to as the computational flow imaging (CFI), and are obtained by combining a fluorescence model for NO 19 with the Reynolds-Averaged Simulation results carried out using the VULCAN-CFD solver. 20 The resulting images are equivalent to the experimentally measured PLIF signal, and are proportional to the NO concentration, and simultaneously exhibit the correct amount of sensitivity to both temperature and pressure.…”

Section: Introductionmentioning

confidence: 86%

“…The same cameras, excitation schemes, etc., were used in other past experiments. 18,19 The fluorescence was imaged onto a gated, intensified charge-coupled device (CCD) (Princeton Instruments PIMAX-II R ), and represented using 16-bits of resolution. A single Nikon R UV lens with a focal length of 105 mm and f/4.5 aperture was used.…”

Section: No Plifmentioning

confidence: 99%

“…All quantities are modeled following the approach of Ivey et al 19 with the model constants and coefficients obtained from LINUS. 38 The above model was applied to the CFD data to obtain CFIs equivalent to those obtained experimentally with PLIF.…”

Section: Fluorescence Modelingmentioning

confidence: 99%

“…38 The above model was applied to the CFD data to obtain CFIs equivalent to those obtained experimentally with PLIF. However, it should be noted that the LIF model used herein has not been formally validated, makes Gaussian assumptions on the shapes of the spectral laser and absorption profiles (i.e., triple-Gaussian assumption 19 ), and neglects the attenuation of the laser light intensity caused by absorption of NO. Under some circumstances, the latter effect can be partially corrected by the image post-processing, as noted during the PLIF image postprocessing discussion.…”

Section: Fluorescence Modelingmentioning

confidence: 99%

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Comparisons Between NO PLIF Imaging and CFD Simulations of Mixing Flowfields for High-Speed Fuel Injectors

Drozda

Cabell

Ziltz

et al. 2017

53rd AIAA/SAE/ASEE Joint Propulsion Conference

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The current work compares experimentally and computationally obtained nitric oxide (NO) planar laser-induced fluorescence (PLIF) images of the mixing flowfields for three types of highspeed fuel injectors: a strut, a ramp, and a rectangular flushwall. These injection devices, which exhibited promising mixing performance at lower flight Mach numbers, are currently being studied as a part of the Enhanced Injection and Mixing Project (EIMP) at the NASA Langley Research Center. The EIMP aims to investigate scramjet fuel injection and mixing physics, and improve the understanding of underlying physical processes relevant to flight Mach numbers greater than eight.In the experiments, conducted in the NASA Langley Arc-Heated Scramjet Test Facility (AHSTF), the injectors are placed downstream of a Mach 6 facility nozzle, which simulates the high Mach number air flow at the entrance of a scramjet combustor. Helium is used as an inert substitute for hydrogen fuel. The PLIF is obtained by using a tunable laser to excite the NO, which is present in the AHSTF air as a direct result of arc-heating. Consequently, the absence of signal is an indication of pure helium (fuel). The PLIF images computed from the computational fluid dynamics (CFD) simulations are obtained by combining a fluorescence model for NO with the Reynolds-Averaged Simulation results carried out using the VULCAN-CFD solver to obtain a computational equivalent of the experimentally measured PLIF signal. The measured NO PLIF signal is mainly a function of NO concentration allowing for semiquantitative comparisons between the CFD and the experiments. The PLIF signal intensity is also sensitive to pressure and temperature variations in the flow, allowing additional flow features to be identified and compared with the CFD. Good agreement between the PLIF and the CFD results provides increased confidence in the CFD simulations for investigations of injector performance.

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Section: Introductionmentioning

confidence: 86%

Section: No Plifmentioning

confidence: 99%

Section: Fluorescence Modelingmentioning

confidence: 99%

Section: Fluorescence Modelingmentioning

confidence: 99%

See 2 more Smart Citations

Comparisons Between NO PLIF Imaging and CFD Simulations of Mixing Flowfields for High-Speed Fuel Injectors

Drozda

Cabell

Ziltz

et al. 2017

53rd AIAA/SAE/ASEE Joint Propulsion Conference

View full text Add to dashboard Cite

show abstract

“…[10][11][12][13][14] It is important to collect experimental data on complex flowfields such as this one to help validate computational fluid dynamics (CFD) models. 15,16 …”

Section: Introductionmentioning

confidence: 99%