Investigation of a dual inlet side dump combustor using liquid fuel injection

Stull, F. D.; Craig, R. R.; Streby, G. D.; Vanka, Surya Pratap

doi:10.2514/6.1983-420

Cited by 8 publications

(6 citation statements)

References 5 publications

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“…Increases in Re, cause (Re, = 120, Model 2) the recirculation areas above the jets alternately to roll off the configuration and flow towards the flow outlet in an irregular and unstable manner. Once the area of recirculation departs, the disc deflects into this area until the recirculation area builds up and the opposite recirculation area rolls off and flows toward the outlet, similar to the results observed by Stull and Craig (1985). Below the area of impingement the disc is directed toward the opposite jet side of the chamber; thus the disc is seen to move as a "solid" body.…”

Section: Flow Visualization 90 < Re < 150supporting

confidence: 72%

“…The flow field visualized had no obvious impingement region, as found in the present study and, above the geometric point of impingement, vortices aligned with the chamber were observed; whereas the present study found vortices aligned with the jet axis for steady and oscillating impingement surfaces. Observations were similar to those of Stull and Craig (1985) in that at one instant, one jet would be deflected into the head area and then deflected out, while the other jet would be deflected into the head area in an "almost periodic and out of phase" manner. The strength of the vortices was found to fluctuate with the oscillation of the jets into the head area (phase locked).…”

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confidence: 63%

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Self‐sustained oscillations in opposed impinging jets in an enclosure

Johnson

Wood

2000

Can J Chem Eng

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he flow field of opposed axisymmetric jets in a confined cavity has been examined for instabilities due to various geometrical and T fluid parameters. Practical examples where such configurations are used are the mix head for reaction injection molding (RIM) and the side dump combustor. RIM involves a rapid mixing process of two or more liquid pre-polymers in a mix chamber that flow into a mold to form a solid polymer part. For most RIM systems, mixing is carried out through directly opposed jet-to-jet impingement of the reactant streams.Stable efficient mixing is paramount to the quality of parts produced with RIM as poorly mixed materials will cause spatial variation in the physical properties and variation in the physical appearance of a finished molded part. Typically, mix chambers are cylindrical and 10 to 15 m m in diameter using nozzles with openings of 0.5 to 3 m m to form the jets near the closed end of the chamber (Figure 1). Fluid issues from the opposed nozzles and may create an impingement region in the mix chamber depending on the geometry and fluid parameters. The closed end is the face of the clean-out piston used to remove the polymer from the nozzle region after completion of the shot. The mixed fluid then leaves the open end of the chamber to the mold. A dimensionless group used to characterize the flow is the Reynolds number, Re,, which is based on the nozzle diameter d, the fluid kinematic viscosity and the volumetric flow rate Q through the nozzle (Q = xd2/4UOvg).Previous visualization studies have shown the existence of an oscillating flow field under some geometric and fluid configurations. They found steady impingement below Re, = 75 (D' = 10.67, D = 25.4 mm, $I = 180"), and a t values higher than this, an instability in the impingement surface began to grow and oscillate. Experimentally, above Red = 150 the jets would not directly impinge, although the computer simulations showed steady oscillations from Re, = 100 to 300. Our interest is in quantifying the range of oscillation parameters and to determine the effect on the stability or performance of the opposed jet mix head configuration. Visualizations of the flow patterns by Sandell et al. (1985) in a mix chamber ( D ' = 5.5, 0 = 30°, H' = 0.73) has shown an oscillating flow above Re, = 150. Generally, the flow became less steady when increasing the Re, or increasing the distance to the head region.In a similar study, Nosseir and Behar (1 986) used a rectangular model with opposed (@ = 180") rectangular jets at an average Re, of 3000 based on nozzle width to simulate the side dump combustor. Oscillations in the flow were detected when the dyed fluid interrupted a laser beam at aThe flow of jets in confining enclosures has significant application in many engineering processes. In particular, the impingement of axisymmetric jets in a confined space has been examined using flow visualization, laser Doppler anemometry, and numerical simulations. Several flow regions were found; stable steady, regular oscillatory, and irregular oscillatory...

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Section: Flow Visualization 90 < Re < 150supporting

confidence: 72%

supporting

confidence: 63%

Self‐sustained oscillations in opposed impinging jets in an enclosure

Johnson

Wood

2000

Can J Chem Eng

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“…Most studies on the turbulent mixing in a T-junction conducted to date have focused on the cross-flow type (a) Cross-flow type T-junction (b) Counter-flow type T-junction Figure 1 Classification of mixing T-junctions T-junction (2)- (7) . As for the counter-flow type T-junction, detailed characteristics of the velocity and scalar fields are not clarified yet (8)- (11) .…”

Section: Introductionmentioning

confidence: 99%

Turbulent Flow and Mixing Characteristics in T-Junction

Hirota

Nakayama

2011

JFST

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The flow and temperature/concentration fields in the mixing channel have complex three-dimensional and unsteady natures that are accompanied by flow separations and reattachments, longitudinal vortices, and large-scale velocity fluctuations. In this paper, detailed experimental results are presented on turbulent flow and mixing characteristics in a counter-flow type T-junction. The test fluid is water, and a fluorescence tracer is dissolved into the main-channel flow. The velocity and concentration fields are measured by PIV and PLIF with high temporal resolutions. At first, the three-dimensional structures of the velocity and concentration fields and the distributions of the turbulent mass fluxes that are dominant in the mixing process of two fluids with different concentrations are addressed. Then, the POD analyses are applied to the fluctuating velocity and concentration fields to extract their dominant structures. Based on the results of the POD, the turbulent mass transport process between two flows is examined.

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“…On the other hand, with regard to the counter-flow type channels shown schematically in Fig. 1, the research has been mainly conducted for combustors (8) (9) , but detailed flow and mixing characteristics and the relationship between the flow structure and the thermal striping are not clarified yet (10) (11) .…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on Turbulent Flow and Mixing in Counter-Flow Type T-Junction

Hirota

Nakayama

Koide

et al. 2007

ASME/JSME 2007 Thermal Engineering Heat Transfer Summer Conference, Volume 1

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An experimental study was conducted on turbulent flow and mixing in a counter-flow type T-junction. We measured the velocity and concentration fields simultaneously by combining PIV and PLIF. Special attention was directed to the concentration fluctuation near the channel wall, which might bring about the high-cycle thermal fatigue in case of mixing of hot and cold flows. The velocity ratio of the counter-channel flow to the main-channel flow was changed from 1.0 to 5.0. The fluorescent dye was mixed in the main-channel flow. The dominant structures of the fluctuating velocity and concentration fields that cause the concentration fluctuation near the channel wall were analyzed by POD. It was found that the concentration fluctuation near the channel wall was caused by the superposition of the spanwise wobbling motion of the mixing interface of two flows and the rotational oscillation of the flows.

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Investigation of a dual inlet side dump combustor using liquid fuel injection

Cited by 8 publications

References 5 publications

Self‐sustained oscillations in opposed impinging jets in an enclosure

Self‐sustained oscillations in opposed impinging jets in an enclosure

Turbulent Flow and Mixing Characteristics in T-Junction

Experimental Study on Turbulent Flow and Mixing in Counter-Flow Type T-Junction

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