Combustor test facility and optical instrumentation for complex turbulent reacting flow

Walterick, R. E.; Groot, W. De; Jagoda, J.; Strahle, Warren C.

doi:10.2514/6.1988-52

Cited by 4 publications

(2 citation statements)

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“…3 However, a close inspection of the shape of the concentration pdf 's revealed a small change in the contribution to the pdf's by dust particles, depending on the local concentrations of the bleed gas. This caused minor changes in the profiles of the mean concentrations but introduced an unacceptable error in the velocity-concentration covariances, which are far more sensitive to the quality of the data.…”

Section: Data Acquisition and Analysismentioning

confidence: 98%

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Combined LDV and Rayleigh measurements in a complex turbulent mixingflow

1989

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IntroductionS OLID fueled ramjets (SFRJ), as other ramjets, require a flame-anchoring region at the head of the combustion chamber. Here the flow must be turbulent to facilitate mixing of fuel and air and have a velocity lower than the flame propagation speed of the mixture. Such a flow exists in the recirculation zone behind a back ward-facing step. The work in this laboratory investigates the complex turbulent flowfield resulting from a fuel injected through a porous plate (to simulate the pyrolysis of a solid fuel) into the recirculation region behind such a back ward-facing step. The part of the study reported here deals with a cold flow simulation of this process. Combined laser Doppler velocimetry (LDV) and molecular Rayleigh scattering were used to determine the flow velocity and bleed gas concentration distributions. In addition, the correlation between the velocity and concentration fluctuations resulted in information about turbulent mass transport in the flowfield. The results of these measurements were compared with the predictions obtained using a modified k-e model, reported elsewhere. 1 ' 2 Experimental WorkThe tunnel used in this investigation has previously been described in detail. 3 Briefly, air drawn from the laboratory passes over a backward-facing step and establishes a recirculation zone. The injectant gas is bled into the recirculation zone through a porous floor behind the step. In the present study, a CO 2 -air mixture was used as the bleed gas since the Rayleigh scattering cross section of CO 2 is 2.4 times that of air. 4 The CO 2 was bled from a large tank filled to 100 psi with compressed CO 2 gas. The long line from the tank to the facility assured that the CO 2 entered the test section close to room temperature. In order to conserve bleed gas, injection was limited to a region between two and eight step heights behind the step. Optical access was provided through antireflection-coated glass side windows.Velocities and bleed gas concentrations were measured simultaneously using a combined LDV-Rayleigh scattering system. The LDV is a TSI, two-component system with Bragg cells using a 5-W argon ion laser. The Rayleigh system used the

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Section: Data Acquisition and Analysismentioning

confidence: 98%

“…3 Briefly, air drawn from the laboratory passes over a backward-facing step and establishes a recirculation zone. The injectant gas is bled into the recirculation zone through a porous floor behind the step.…”

Section: Experimental Workmentioning

confidence: 99%