Finite Conductivity Evaporation Modeling of Liquid Jet in High-Speed Cross-Flow

Author(s):  
Madhanabharatam Balasubramanyam ◽  
Chien Chen
Author(s):  
Tushar Sikroria ◽  
Abhijit Kushari

Abstract This paper presents the experimental analysis of the impact of swirl number of cross-flowing air stream on liquid jet spray trajectory at a fixed air flow velocity of 42 m/s with the corresponding Mach number of 0.12. The experiments were conducted for 4 different swirl numbers (0, 0.2, 0.42 and 0.73) using swirl vanes at air inlet having angles of 0°, 15°, 30° and 45° respectively. Liquid to air momentum flux ratio (q) was varied from 5 to 25. High speed (@ 500 fps) images of the spray were captured and those images were processed using MATLAB to obtain the path of the spray at various momentum flux ratios. The results show interesting trends for the spray trajectory and the jet spread in swirling air flow. High swirling flows not only lead to spray with lower radial penetration due to sharp bending and disintegration of liquid jet, but also result in spray with high jet spread and spray area. Based on the results, correlations for the spray path have been proposed which incorporates the effects of the swirl number of the air flow.


Author(s):  
Tushar Sikroria ◽  
Abhijit Kushari ◽  
Saadat Syed ◽  
Jeffery A. Lovett

This paper presents the results of an experimental investigation of liquid jet breakup in a cross flow of air under the influence of swirl (swirl numbers 0 and 0.2) at a fixed air flow Mach number 0.12 (typical gas turbine conditions). The experiments have been conducted for various liquid to air momentum flux ratios (q) in the range of 1 to 25. High speed (@ 500 fps) images of the jet breakup process are captured and those images are processed using matlab to obtain the variation of breakup length and penetration height with momentum flux ratio. Using the high speed images, an attempt has been made to understand the physics of the jet breakup process by identification of breakup modes—bag breakup, column breakup, shear breakup, and surface breakup. The results show unique breakup and penetration behavior which departs from the continuous correlations typically used. Furthermore, the images show a substantial spatial fluctuation of the emerging jet resulting in a wavy nature related to effects of instability waves. The results with 15 deg swirl show reduced breakup length and penetration related to the nonuniform distribution of velocity that offers enhanced fuel atomization in swirling fuel nozzles.


2021 ◽  
Author(s):  
Si. Kasmaiee ◽  
M. Tadjfar ◽  
Sa. Kasmaiee

Abstract One of the most common ways to obtain mixing between liquid and air, is by injecting the liquid jet into an incoming gaseous crossflow. The physics of this mixing flow is very complicated due to the presence of many flow interfacial instabilities. Usually, a perpendicular liquid jet into the cross flow airstream is used as the standard method of mixing. In the present work, the effect of the injection angle of the liquid flow emanated from a circular nozzle into airstream was experimentally investigated. The flow characteristics of the liquid jet were visualized by diffused backlight shadowgraph technique and high-speed photography. Water was used as the working liquid and tests were conducted into an incoming airstream at room temperature and pressure. A circular nozzle with 1.5 mm in diameter was used. The injection angles of the 30, 45, 60 and 90 degrees of the liquid jet into the airstream were considered. Different parameters of liquid jet flow such as breakup length and trajectory were measured. It was found that at low angles the path was independent from the momentum ratio.


Author(s):  
Tushar Sikroria ◽  
Abhijit Kushari ◽  
Saadat Syed ◽  
Jeffery A. Lovett

This paper presents the results of an experimental investigation of liquid jet breakup in a cross-flow of air under the influence of swirl (swirl numbers 0 and 0.2) at a fixed air flow Mach No. 0.12 (typical gas turbine conditions). The experiments have been conducted for various liquid to air momentum flux ratios (q) in the range of 1 to 25. High speed (@ 500 fps) images of the jet breakup process are captured and those images are processed using MATLAB to obtain the variation of breakup length and penetration height with momentum flux ratio. Using the high speed images, an attempt has been made to understand the physics of the jet breakup process by identification of breakup modes — bag breakup, column breakup, shear breakup and surface breakup. The results show unique breakup and penetration behavior which departs from the continuous correlations typically used. Furthermore, the images show a substantial spatial fluctuation of the emerging jet resulting in a wavy nature related to effects of instability waves. The results with 15° swirl show reduced breakup length and penetration related to the non-uniform distribution of velocity that offers enhanced fuel atomization in swirling fuel nozzles.


Author(s):  
H. Sapmaz ◽  
B. Alkan ◽  
C. X. Lin ◽  
C. Ghenai

The success of supersonic air-breathing propulsion systems will be largely dependent on efficient injection, mixing, and combustion inside the supersonic combustion chamber. Fuel/air mixing enhancement inside the combustion chamber will depend on the strategies used to control the fuel jet penetration and liquid fuel droplet size, trajectory, and dispersion. We present in these paper experimental results on the mixing of pure liquid jet, aerated liquid jet and pulsed aerated liquid jet in supersonic cross flow. Transverse aerated liquid jet injection will offer relatively rapid near-field mixing, good fuel penetration and better atomization of liquid fuel. Fully modulated or pulsed fuel jet injection will introduce additional supplementary turbulent mixing. High speed imaging system is used in this study for the visualization of the injection of liquid jet in high speed cross flow. The results presented in this paper show the effect of jet/cross flow momentum ratio, the gas/liquid mass ratio and pulsing frequency on the penetration of aerated liquid jet in supersonic cross-flow. The data generated in this study will be used for the development of active control strategies to optimize the liquid fuel jet penetration and supersonic fuel/air mixing.


2005 ◽  
Author(s):  
C. Ghenai ◽  
H. Sapmaz ◽  
C. X. Lin

The success of supersonic air-breathing propulsion systems will be largely dependent on efficient injection, mixing, and combustion inside the supersonic combustion chamber. Fuel/air mixing enhancement inside the combustion chamber will depend on the strategies used to control the fuel jet penetration and liquid fuel droplet size, trajectory, and dispersion. We present in this paper experimental results on the penetration and mixing of aerated liquid fuel jet in supersonic cross flow (M=1.5). The aerated liquid jet or the barbotage technique where a small amount of gas is added to the liquid fuel will accelerate the atomization of the liquid jet and offer a good fuel penetration. High speed imaging system is used in this study for the visualization of pure and aerated liquid jet. For the aerated liquid jet the gas/liquid mass ratio was varied between 0 and 9.9 %. The results presented in this paper shows the effect of jet/cross flow momentum ratio, and gas/liquid mass ratio on the structure and penetration of aerated liquid jet (methanol) in high speed cross flow. The data generated in this study are used for the development of active control strategies to optimize the liquid fuel jet penetration and supersonic fuel/air mixing.


1998 ◽  
Vol 8 (2) ◽  
pp. 155-178 ◽  
Author(s):  
J. H. Hilbing ◽  
Stephen D. Heister

2007 ◽  
Vol 17 (1) ◽  
pp. 47-70 ◽  
Author(s):  
Raffaele Ragucci ◽  
Alessandro Bellofiore ◽  
Antonio Cavaliere
Keyword(s):  

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 797
Author(s):  
Stefan Hoerner ◽  
Iring Kösters ◽  
Laure Vignal ◽  
Olivier Cleynen ◽  
Shokoofeh Abbaszadeh ◽  
...  

Oscillating hydrofoils were installed in a water tunnel as a surrogate model for a hydrokinetic cross-flow tidal turbine, enabling the study of the effect of flexible blades on the performance of those devices with high ecological potential. The study focuses on a single tip-speed ratio (equal to 2), the key non-dimensional parameter describing the operating point, and solidity (equal to 1.5), quantifying the robustness of the turbine shape. Both parameters are standard values for cross-flow tidal turbines. Those lead to highly dynamic characteristics in the flow field dominated by dynamic stall. The flow field is investigated at the blade level using high-speed particle image velocimetry measurements. Strong fluid–structure interactions lead to significant structural deformations and highly modified flow fields. The flexibility of the blades is shown to significantly reduce the duration of the periodic stall regime; this observation is achieved through systematic comparison of the flow field, with a quantitative evaluation of the degree of chaotic changes in the wake. In this manner, the study provides insights into the mechanisms of the passive flow control achieved through blade flexibility in cross-flow turbines.


Sign in / Sign up

Export Citation Format

Share Document