Effect of rotation on Bunsen flame

Sheu, Wen-Jenn; Sohrab, Siavash H.; Sivashinsky, G. I.

doi:10.1016/0010-2180(90)90043-q

Cited by 23 publications

(7 citation statements)

References 6 publications

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“…A rotating honeycomb is used to create solid-body rotation of the premixed gases that exit the burner [13][14][15]. The vertical burner tube is supported by bearings and is connected by a pulley-belt system to a DC motor.…”

Section: Experimental Apparatus and Methodsmentioning

confidence: 99%

Orbital instability and prediction of a Bunsen flame tip motion with burner rotation

Gotoda

Ueda

2005

Combustion and Flame

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Section: Experimental Apparatus and Methodsmentioning

confidence: 99%

Orbital instability and prediction of a Bunsen flame tip motion with burner rotation

Gotoda

Ueda

2005

Combustion and Flame

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“…A short honeycomb is installed in the burner tube to give rigid-body rotation of the CH 4 -air mixtures. 10,11 The burner tube is vertically supported by bearings and connected by a pulley-belt system to a dc motor. As reported in our previous studies, 14 the flame shape and flame motion depend on the Lewis number, and the oscillating flame is formed when the Lewis number Le is larger than unity, that is, a rich CH 4 -air mixture and lean C 3 H 8 -air mixture.…”

Section: Experimental Apparatus and Methodsmentioning

confidence: 99%

“…Flame motions on the rotating burner at various velocity, stoichiometry, and rotation rates have been investigated with or without the Lewis number effect in normal gravity (see Refs. [10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Dynamic Motion of Rotating Bunsen Flame Tip in Microgravity

Gotoda¹,

Ueda

Cheng

2004

AIAA Journal

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Fig. 4 Comparison of the velocity profile parameters with the separation correlations. Fig. 5 Mean velocity distributions compared with Eq. (1).The point of zero-mean surface shear stress separation, τ w = 0, is more of academic interest, although it plays an important role in the development of skin-friction relations 4 and empirical velocity profile representation.The Sandborn-Kline 5 τ w = 0 correlation was obtained by employing an empirical laminar velocity separation profile, 6(1) Figure 5 shows a comparison of the TAD velocity profile at 170 deg and Re = 5 × 10 5 with Eq. (1) for the case m = 4. Equation (1) is also compared with the 170-deg, Re = 2 × 10 5 data in Fig. 2. It was assumed that the normal coordinate n was equivalent to y. The profile (Fig. 5) is beyond the point of τ w = 0; however, the agreement with Eq. (1) for the outer region of the profile τ w = 0 is reasonable. The tabulated law of the wake function, 7 which is found to be one unique case of Eq. (1) for m = 2.1, is also shown in Fig. 5. The value of δ for the law of the wake was taken at the point where U/U e = 0.995, which is consistent with the requirements of the measured profiles. 4 Equation (1) can be employed for a wide range of flows and is not limited to large aerodynamic flows. ConclusionsThe velocity distribution in a complex, small radius of curvature, TAD shear flow was shown to follow closely the separation model developed for canonical, two-dimensional, large-Reynolds-number, turbulent boundary layers. The TAD flow produces a very thin shear layer along the inner surface of the initial 90 deg of the turn. Beyond 90 deg, the inner wall shear layer thickens and develops to the start of separation by approximately 150 deg around the turn. The shear layer velocity shape parameters are found to develop through the separation region as predicted by the Sandborn-Kline separation model.The mean velocity distributions in the region of zero-mean surface shear stress separation were shown to agree with equivalent laminar separation profiles.

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“…It comprises a natural gas cylinder (1) that is equipped with the pressure regulator (2), a centrifugal air blower (18) and orifice meter arrangements (4) and (17) to measure the flow rate across the air and fuel feeding pipes (3) and (16), respectively. The flow switch between the premixed and nonpremixed flame modes is employed with the aid of the ball valves (13) and (15).…”

Section: Experimental Test Rig and Layoutmentioning

confidence: 99%

“…1 Swirling flow and pulsating flow are examples of two interactive flow disturbances. Although swirling flow is known to be superior for introducing severe strain rates, 2 limited research was found in the literature concerning the rotary vane swirl flames (including the studies reported by Sivashinsky et al, 3 Sheu et al, 4 Sakai and Ishizuka 5 and Dwyer and Hasegawa 6 ). On the other hand, the pulsating flow is a particular kind of unsteady flow configuration in which there is a regular cyclic variation in the flow velocity superimposed on a constant timeaveraged flow rate.…”

Section: Introductionmentioning

confidence: 99%

Combustion performance of eccentrically rotated flames

Ismael

Abdelkhalek

Kamal

2013

Proceedings of the Institution of Mechanical Engineers, Part A:

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Experimental/computational work highlighted the combustion performance with eccentric blockage rotation in the reactive flow passage to augment the turbulence production rates in the flame for acquiring high power to weight ratios and effective heat transfer in industrial applications. The temporal/spatial velocity gradients stimulated around the reactive stream boundaries enhanced the turbulence development in both premixed and non-premixed flames. The eccentric shapes included circular, elliptical, squared and triangular shafts as well as a triple/straight blade rotor. The design was further developed to incorporate simultaneous rotation of the eccentric blockage around its axis via a planetary gear assembly to duplicate the vortical structure. While the premixed flames responded to such cyclic action by having a mixture velocity of 16.8 m/s, the non-premixed flames acquired an increase of 341% in the largest eddy size and a flame length reduction by 42%. Increasing the Strouhal number to 0.94 and the swirl ratio to 0.78 increased the turbulent kinetic energy to 9.1 m 2 /s 2 . By controlling the drag coefficient and wake vorticity for the solid shapes, the triangular rotor enhanced the combustor outward heat flux to exhibit a heater efficiency of 36.8% in the premixed flame mode and reduced the HC and CO emissions, respectively, to 0.1% and 513 ppm for non-premixed flames. Decreasing the reactive stream cross-section favorably increased the flow shearing effects, while the elliptical shape showed the highest sensitivity to axes' orientation with respect to the direction of rotation. Due to the reduction in peak temperatures via increasing the turbulence intensity and heat transfer rate from the flame, the NO x exhaust concentrations decreased to a minimum value around 10 ppm. The combustion efficiency of diffusion flames was optimized with the fuel port central positioning in the burner, where the planetary gear design provided a turbulence intensity of 13.7% by the triple blade rotor.

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Effect of rotation on Bunsen flame

Cited by 23 publications

References 6 publications

Orbital instability and prediction of a Bunsen flame tip motion with burner rotation

Orbital instability and prediction of a Bunsen flame tip motion with burner rotation

Dynamic Motion of Rotating Bunsen Flame Tip in Microgravity

Combustion performance of eccentrically rotated flames

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