Effects of Swirl Coaxial Injector Parameters on LOX/GH2 Engine Combustion Performance

Zhuang, Feng; Sun, Jianqiang

doi:10.2514/6.2002-3697

Cited by 4 publications

(5 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, selfpulsation can always occur as long as the gas momentum flux is large enough according to Bazarov and Yang's theory [4]. Im et al [11] demonstrated that increasing recess length can intensify self-pulsation. This agrees with the present study when the flow moves from outer mixing to critical mixing by increasing the recess length.…”

Section: F Self-pulsation Mechanismmentioning

confidence: 98%

“…Among these geometrical parameters, recess length acts as a key parameter in determining self-pulsation characteristics. Im et al [6,11] figured out that the self-pulsation zone becomes wider when increasing the recess length, whereas self-pulsation frequency has no clear trends. However, Bazarov et al [4,7] found that there exists an optimum recess length, making the self-pulsation zone the widest.…”

Section: Introductionmentioning

confidence: 94%

“…The selfpulsation frequency is the frequency at which the spray oscillates. It can be obtained from either a series of instantaneous spray images or acoustic frequency because self-pulsation is accompanied by an intense screech [5], and the frequency of the spray oscillation is the same as that of the acoustic [11]. The self-pulsation characteristics of the LCSC injector are greatly influenced by injection conditions and injector geometrical parameters.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Effects of Recess on the Self-Pulsation Characteristics of Liquid-Centered Swirl Coaxial Injectors

Kang

Cheng

et al. 2016

Journal of Propulsion and Power

View full text Add to dashboard Cite

The self-pulsation characteristics of liquid-centered swirl coaxial injectors have been investigated using a Photron Fastcam SA-1.1 camera and a PULSE system (B&K Corp., 3650 type). The effects of both recess length and injection condition were analyzed and discussed. The flow pattern in the recess chamber of a liquid-centered swirl coaxial injector can be classified into three types, namely, outer, critical, and inner mixing flow. Once the critical flow approaches, self-pulsation is about to occur. When self-pulsation occurs, the spray oscillates with a Christmas tree shape. The Christmas-tree-like spray periodically produces droplet clusters, making horizontal spray width and mass flux oscillate periodically. Self-pulsation is the strongest when the flow is around the critical mixing flow. Both variations of recess length and injection condition can change the flow pattern in the recess chamber. When the flow pattern moves away from the critical mixing flow, self-pulsation is suppressed. All the frequency behaviors of selfpulsation indicate that self-pulsation is strongly related to Kelvin-Helmholtz instability. A possible mechanism of selfpulsation is also presented. This mechanism interprets the experiments of the present study and the results of literature well. Nomenclature D = diameter or distance, m h = film thickness, m k = specific heat ratio L = length, m _ m = mass flow rate, kg∕s P = pressure, Pa R = swirling radius or gas constant T = temperature, K u = axial velocity, m∕s w = circumferential velocity, m∕s α = spray angle, deg Δ = difference θ = convergent angle of the pressure swirl injector, deg μ = dynamic viscosity, Pa · s ρ = density, kg∕m 3 σ = pressure ratio φ = recess angle, deg Subscripts a = atmosphere cr = critical l = liquid li = liquid injector g = gas ir = inner or = outer r = recess s = swirl chamber t = tangential hole

show abstract

Section: F Self-pulsation Mechanismmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effects of Recess on the Self-Pulsation Characteristics of Liquid-Centered Swirl Coaxial Injectors

Kang

Cheng

et al. 2016

Journal of Propulsion and Power

View full text Add to dashboard Cite

show abstract

“…Previous studies by Oefelein on atomization and combustion characteristics with a shear coaxial injector have looked into the shear coaxial injection process in liquid rocket combustion. 12 In his research, Oefelein 13 found that surface tension forces emanated a heterogeneous spray and that the diminished intermolecular forces increased a diffusion process prior to atomization and jet vaporization. Another investigation of atomization and combustion with a shear coaxial injector was presented by Mayer et al 14 They observed that the spray, including various droplets, no longer existed at combustion conditions, and they noted that the flame existed in the recirculation zone behind the injector post.…”

Section: Introductionmentioning

confidence: 99%

“…However, combustion characteristics using a tricoaxial injector configured with an inner- and outer-stage have rarely been studied. Previous studies by Oefelein on atomization and combustion characteristics with a shear coaxial injector have looked into the shear coaxial injection process in liquid rocket combustion . In his research, Oefelein found that surface tension forces emanated a heterogeneous spray and that the diminished intermolecular forces increased a diffusion process prior to atomization and jet vaporization.…”

Section: Introductionmentioning

confidence: 99%

Atomization and Combustion Characteristics of Ethanol/Nitrous Oxide at Various Momentum Flux Ratios

2014

View full text Add to dashboard Cite

The flame structure of ethanol and nitrous oxide combustion was experimentally studied using a tricoaxial injector at various momentum flux ratios. The objects of the study were to investigate the effects of the additional supplement of nitrous oxide that gas jets inject at the outer annular gap at various injection velocities and to obtain and analyze the flame structure. The fully developed patterns due to the transfer of momentum and viscosity mixing were similar to that of the axial flow when the measurement position was increased from Z/d = 1 to Z/d = 10. The correlation equation, using the momentum flux ratio, was used along with the linear regression method to calculate the breakup length and Sauter mean diameter (SMD). The effects were clearly observed and significant. The inner gas injection caused the SMD to decrease, and the outer gas injection was able to create a boundary layer around the spray jets. As the momentum flux ratio of the inner gas jets increased, the spray angle and flame angle increased. OH radicals extended toward the rear flame region with the increase in momentum flux ratio from the inner gas jets. As the momentum flux of the outer gas jets increased, the boundary of the OH radicals developed and the intensity of the OH radicals generated in the flame region was enhanced. Also, the flame temperature increased as gas was injected from the outer-stage.

show abstract

Control Effects of Baffle on Combustion Instability in a LOX/GH2 Rocket Engine

Feng

Nie

et al. 2010

Journal of Spacecraft and Rockets

View full text Add to dashboard Cite

Effects of Swirl Coaxial Injector Parameters on LOX/GH2 Engine Combustion Performance

Cited by 4 publications

References 2 publications

Effects of Recess on the Self-Pulsation Characteristics of Liquid-Centered Swirl Coaxial Injectors

Effects of Recess on the Self-Pulsation Characteristics of Liquid-Centered Swirl Coaxial Injectors

Atomization and Combustion Characteristics of Ethanol/Nitrous Oxide at Various Momentum Flux Ratios

Control Effects of Baffle on Combustion Instability in a LOX/GH2 Rocket Engine

Contact Info

Product

Resources

About