PULSE RADIOGRAPHY INVESTIGATION OF LIQUID JET FLOW STRUCTURE IN A NONTRANSPARENT MEDIUM

Author(s):  
V. L. Ovsiannikov ◽  
A. R. Berngardt ◽  
E. I. Pal'chikov
Keyword(s):  
Jet Flow ◽  
2005 ◽  
Vol 60 (17) ◽  
pp. 4886-4900 ◽  
Author(s):  
Toshiyuki Sanada ◽  
Masao Watanabe ◽  
Tohru Fukano ◽  
Akira Kariyasaki

Author(s):  
Zhiliang Zhang ◽  
Jiaqi Lu ◽  
Bingqian Lv ◽  
Wei Liu ◽  
Shuyuan Shen ◽  
...  

The gas-liquid jet flow was proved to be capable of inducing chemical consequences which can lead to the decomposition of methylene blue (MB). The reaction process follows a pseudo-first-order kinetics....


2005 ◽  
Vol 128 (3) ◽  
pp. 380-390 ◽  
Author(s):  
Bogdan R. Kucinschi ◽  
Ronald C. Scherer ◽  
Kenneth J. DeWitt ◽  
Terry T. M. Ng

Flow visualization with smoke particles illuminated by a laser sheet was used to obtain a qualitative description of the air flow structures through a dynamically similar 7.5× symmetric static scale model of the human larynx (divergence angle of 10deg, minimal diameter of 0.04cm real life). The acoustic level downstream of the vocal folds was measured by using a condenser microphone. False vocal folds (FVFs) were included. In general, the glottal flow was laminar and bistable. The glottal jet curvature increased with flow rate and decreased with the presence of the FVFs. The glottal exit flow for the lowest flow rate showed a curved jet which remained laminar for all geometries. For the higher flow rates, the jet flow patterns exiting the glottis showed a laminar jet core, transitioning to vortical structures, and leading spatially to turbulent dissipation. This structure was shortened and tightened with an increase in flow rate. The narrow FVF gap lengthened the flow structure and reduced jet curvature via acceleration of the flow. These results suggest that laryngeal flow resistance and the complex jet flow structure exiting the glottis are highly affected by flow rate and the presence of the false vocal folds. Acoustic consequences are discussed in terms of the quadrupole- and dipole-type sound sources due to ordered flow structures.


2010 ◽  
Vol 29-32 ◽  
pp. 1675-1679
Author(s):  
Zhen Tao Wang ◽  
Jun Feng Wang ◽  
Wei Dong Jia ◽  
Ti Qian Luo

The electrostatic jet flow has been widely employed to crop-dusting, painting, fuel spray and combustion, electrostatic painting, dust particles and flue gas removal. In order to investigate the convolution flow structure near the nozzle, discuss the effects of electrostatic voltages on convolution flow form, development and the aggrandizement of droplets mass transfer. PIV (Particle Image Velocimetry) was employed to measure and analyze the convolution flow near the nozzle under different voltages, and the velocity vectors and streamlines were gained. Experiment and analysis indicate that convolution flow structure has been existed in electrostatic jet flow brim and the main jet flow section change is inconspicuous with voltages adding; Electrical filed intensity has been enhanced and the droplets convolution flow was picked up with the electrostatic voltages adding. The convolution flow structure could quicken the gas mix into the main jet flow, and enhanced the droplets absorbency.


2018 ◽  
Vol 9 (2) ◽  
pp. 42
Author(s):  
S Setiadi ◽  
Dijan Supramono ◽  
Nur Istiqomah

Efforts to improve the performance of CO2 absorption using bubbling columns and liquid jet flow have consistently been developed. The advantage of the present column is the presence of gas entrainment by suction of nozzle and the gas dispersed throughout the bulk of liquid by the formation of bubble clouds. The selection of liquid jet flow configuration used parameters of nozzle position and liquid jet inclination. The configurations have been examined by hydrodynamic test by measuring the ratio of volumetric rate of gas to that of liquid exiting nozzle (QG/QL) and gas holdup. Absorption test to the best configuration used NaOH solution with flowrate of 5 litres/min at atmospheric pressure and CO2 gas feed of 96.6%. The results showed that the configurations of liquid jet flow gave significant effect on hydrodynamics and that the best configurations had gas hold-up in the range of 0.55-0.6 and QG/QL 1.3-1.8. Absorption tests showed that CO2 concentration can be reduced into 0.01%-0.07% in less than five minutes and the absorption should proceed with the chemical reaction up to 10 minutes with no indication of CO2 desorption. The bubbles were generated in the column predominantly in the diameter range of 0.00097-0.00184 mm.Keywords: Configurations of liquid jet, bubble column, gas entrainment, CO2 gas absorption AbstrakUpaya meningkatkan kinerja absorpsi gas CO2 yang memanfaatkan kolom gelembung dan liquid jet flow telah banyak dilakukan. Keunggulan kolom gelembung dalam riset ini adalah kolom menyebabkan gas entrainment (pengisapan gas) dan dispersi gas ke dalam cairan yang membentuk awan gelembung. Pemilihan konfigurasi liquid jet flow terbaik berdasarkan posisi nosel dan arah sudut tembakannya dan dengan mengukur rasio laju volumetrik aliran gas entrainment terhadap laju volumetrik aliran cairan (QG/QL) serta gas hold-up untuk setiap konfigurasi. Konfigurasi terbaik digunakan untuk menentukan kinerja kolom gelembung untuk mendapatkan kinerja kemampuan absorpsi yang setinggi-tingginya. Uji absorpsi dilakukan terhadap konfigurasi terbaik dengan menggunakan absorben larutan NaOH dengan laju alir 5 L/min pada tekanan atmosferik dan umpan gas CO2 dengan kadar 96,6%. Hasil penelitian menunjukkan bahwa konfigurasi memberikan pengaruh cukup signifikan dan bahwa konfigurasi terbaik memberikan gas hold-up kisaran 0,55-0,65 dan rasio QG/QL bernilai 1,3-1,8. Uji absorpsi menunjukkan berkurangnya kadar CO2 menjadi 0,01% hingga 0,07% setelah absorpsi kurang dari 5 menit dan tetap tidak berubah sampai 10 menit. Hal ini menandakan bahwa absorpsi terjadi secara kimiawi antara gas CO2 dan NaOH and tidak terjadi desorpsi walaupun kolom gelembung tetap resirkulasi. Populasi gelembung menunjukkan distribusi ukuran gelembung lebih dominan pada rentang diameter antara 0,00097-0,00184 mm.Kata Kunci: Konfigurasi liquid jet, kolom gelembung, gas entrainment, absorpsi gas CO2


2019 ◽  
Vol 22 (1) ◽  
pp. 243-256 ◽  
Author(s):  
Rubby Prasetya ◽  
Akira Sou ◽  
Junichi Oki ◽  
Akira Nakashima ◽  
Keiya Nishida ◽  
...  

Two kinds of cavitation may occur in mini-sac type diesel injectors. The first is geometrical cavitation, which can usually be seen as a film-like structure in the nozzle. The second is the filament-like string cavitation. Both types of cavitation are known to affect fuel spray characteristics, although the effects of geometrical cavitation and that of string cavitation have not been individually clarified. Moreover, the mechanism behind string cavitation occurrence is still unclear. String cavitation usually occurs at low needle lift, which might indicate the existence of a vortex ring flow in the sac. However, because of the difficulty in precise flow measurement of the three-dimensional flow structure in the sac, the link between vortex ring flow and string cavitation occurrence in the sac has not been proven. In this study, high-speed imaging of string cavitation, geometrical cavitation, and discharged liquid jet of an enlarged three-hole mini-sac diesel fuel injector was conducted to individually clarify the effects of string cavitation and geometrical cavitation on the discharged liquid jet angle. Furthermore, tomographic–stereo particle image velocimetry was carried out on the sac. The experiments were conducted at two different needle lifts, to clarify the link between needle lifts and flow structure in the sac, as well as how it affects string cavitation occurrence and liquid jet angle. The results confirmed that at low needle lift, vortex ring flow forms in the sac, which may induce helical flow in the nozzle, resulting in a large jet angle. Vortex strength varies with time, and string cavitation occurs when the vortex is particularly strong. As a result, the magnitude of the jet angle increase at low needle lift is enhanced when string cavitation occurs. At high needle lift, flow pattern in the sac becomes relatively uniform, which makes it harder for string cavitation to form.


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