Breakup Behaviour of Like-impinging Type Rocket Injectors
0
Citation
0
Reference
20
Related Paper
Keywords:
Rocket (weapon)
Cite
An experimental investigation of the effects of turbulence on primary breakup of round liquid jets subjected to gaseous crossflow is described. The paper investigates the effects of partial degrees of turbulence development in the liquid. Measurements of the properties of primary breakup were obtained using double-pulsed shadowgraphy in a subsonic wind tunnel having a test section of 0.3 m × 0.3 m × 0.6 m. Measurements included primary breakup regimes, conditions required for the onset of breakup, ligament properties along the liquid surface, drop size and velocity distributions after breakup along the liquid surface, conditions required for breakup of the liquid jet as a whole, and liquid jet trajectories.
Shadowgraphy
Weber number
Cite
Citations (3)
In this work, atomization of the liquid sheet formed by two like-on-like impinging liquid jets is studied experimentally. The primary focus of this study concerns sheet breakup due to the formation and growth of perforations on the liquid sheet. In this mode of atomization, perforations or holes originate at a location where the liquid sheet becomes thin due to stretching. As time elapses, these perforations will grow in size and move either toward the bottom or toward the rim of the sheet. Depending on the initial location of their formation, these perforations either interact with the rim of the sheet or with other surrounding perforations and disintegrate the sheet into ligaments, which further disintegrate into drops. The phenomenon of perforation formation and growth is captured using a high-speed backlight imaging technique and processed using in-house-developed image processing algorithms based on MATLAB. The effect of liquid properties and Reynolds number on the growth of perforations is studied in this work. Based on the experiments conducted in this study, perforation-based atomization is broadly classified into three different modes. In the first mode, a single perforation interacts with the rim and disintegrates the sheet into ligaments. In the second mode, two or more perforations interact, and their common area of interaction is disintegrated into ligaments and droplets. In the third mode, the liquid sheet breaks up due to perforation interaction with impact waves. Studies on atomization behavior of the liquid sheet at high ambient pressure up to 0.8 MPa revealed improved atomization.
Perforation
Mode (computer interface)
Weber number
Break-Up
Cite
Citations (3)
Atomization caused by impinging two liquid jets at an angle was studied experimentally and analytically. Measurements of drop size, sheet length and width at breakup, and apparent wave structures on the liquid sheet surface were made for different flow conditions and different geometries. The breakup of the attenuating liquid sheet into ligaments was modeled by linear stability theory. Breakup lengths were predicted from the fastest growing wave on the sheet surface, and drop diameters were calculated based on surface tension-controlled breakup of the ligaments.
Cite
Citations (36)
Cite
Citations (3)
The breakup characteristics of liquid sheets formed by the impinging and swirl type injectors were studied as increasing the Weber number (or injection condition) and the ambient gas pressure up to 4.0MPa. In the case of impinging type injector, we compared the changes of breakup lengths between laminar and turbulent sheets, which are formed by the impingement of laminar and turbulent jets, respectively. The results showed that both sheets expand as increasing the injection velocity irrespective of the ambient gas density when the gas based Weber number is low. When the Weber number is high, however, the breakup of turbulent sheet depends on the hydraulic force of jets as well as the aerodynamic force of ambient gas which determines the breakup of laminar sheet. Using the experimental results, we could suggest empirical models on the breakup lengths of laminar and turbulent sheets. In the case of swirl type injector, as Wel and ambient gas density increased, the disturbances on the annular liquid sheet surface were amplified by the increase of the aerodynamic forces, and thus the liquid sheet disintegrated near from the injector exit. Finally, the measured breakup length of swirl type injector according to the ambient gas density and Wel was compared with the result by the linear instability theory. We found that the corrected breakup length relation derived from linear instability theory considering the attenuation of sheet thickness agrees well with our experimental results
Weber number
Cite
Citations (0)
Cite
Citations (0)
Cite
Citations (0)
Department of Mechanical and Material Engineering, University of Western Ontario, London, Ontario, Canada Experimental investigations have been carried out for the breakup process of an annular water jet exposed to an inner air stream by videographic and photographic techniques. Three flow regimes for the jet breakup process have been identified—i.e., bubble formation, annular jet formation, and atomization. Within the bubble formation regime, the jet breakup characteristics measured from the photographs taken under various liquid and gas velocities indicate that nearly uniform bubbles were observed for various air-to-water velocity ratios; both the jet breakup length and the wavelength for bubble formation decreased as the air-to-water velocity ratio was increased. The measurements were compared with the predictions by linear instability analysis, and fair agreement was obtained
Weber number
Break-Up
Liquid bubble
Cite
Citations (19)
Break-Up
Ligand cone angle
Weber number
Cite
Citations (17)