An Experimental Investigation on Liquid Sheet Breakup due to Perforations in Impinging Jet Atomization

2021 ◽  
Author(s):  
Nikhil Kumar Etteneni ◽  
Madan Mohan Avulapati
Keyword(s):  
Experimental Investigation ◽  
Impinging Jet ◽  
Liquid Sheet ◽  
Sheet Breakup

Modeling of Gas Turbine Fuel Nozzle Spray

1997 ◽  
Vol 119 (1) ◽  
pp. 34-44 ◽  
Author(s):  
N. K. Rizk ◽  
J. S. Chin ◽  
M. K. Razdan
Keyword(s):  
Gas Turbine ◽  
Fuel Injection ◽  
Near Field ◽  
Continuous Phase ◽  
Liquid Sheet ◽  
Vapor Concentration ◽  
Fuel Vapor ◽  
Fuel Injector ◽  
Gas Temperature ◽  
Sheet Breakup

Satisfactory performance of the gas turbine combustor relies on the careful design of various components, particularly the fuel injector. It is, therefore, essential to establish a fundamental basis for fuel injection modeling that involves various atomization processes. A two-dimensional fuel injection model has been formulated to simulate the airflow within and downstream of the atomizer and address the formation and breakup of the liquid sheet formed at the atomizer exit. The sheet breakup under the effects of airblast, fuel pressure, or the combined atomization mode of the airassist type is considered in the calculation. The model accounts for secondary breakup of drops and the stochastic Lagrangian treatment of spray. The calculation of spray evaporation addresses both droplet heat-up and steady-state mechanisms, and fuel vapor concentration is based on the partial pressure concept. An enhanced evaporation model has been developed that accounts for multicomponent, finite mass diffusivity and conductivity effects, and addresses near-critical evaporation. The presents investigation involved predictions of flow and spray characteristics of two distinctively different fuel atomizers under both nonreacting and reacting conditions. The predictions of the continuous phase velocity components and the spray mean drop sizes agree well with the detailed measurements obtained for the two atomizers, which indicates the model accounts for key aspects of atomization. The model also provides insight into ligament formation and breakup at the atomizer exit and the initial drop sizes formed in the atomizer near field region where measurements are difficult to obtain. The calculations of the reacting spray show the fuel-rich region occupied most of the spray volume with two-peak radial gas temperature profiles. The results also provided local concentrations of unburned hydrocarbon (UHC) and carbon monoxide (CO) in atomizer flowfield, information that could support the effort to reduce emission levels of gas turbine combustors.

Dynamics of Liquid Sheet Breakup in Splash Plate Atomization

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
G. Thunivumani ◽  
Hrishikesh Gadgil
Keyword(s):  
Solid Surface ◽  
Weber Number ◽  
Jet Impingement ◽  
Liquid Sheet ◽  
Force Balance ◽  
Impingement Angle ◽  
Wide Range ◽  
Perforated Sheet ◽  
Sheet Breakup ◽  
Regime Map

An experimental study was conducted to investigate the breakup of a liquid sheet produced by oblique impingement of a liquid jet on a plane solid surface. Experiments are carried out over a wide range of jet Weber number (80–6300) and various jet impingement angles (30 deg, 45 deg, and 60 deg) are employed to study the sheet dynamics. The breakup of a liquid sheet takes place in three modes, closed rim, open rim, and perforated sheet, depending upon the Weber number. The transitions across the modes are also influenced by the impingement angle with the transition Weber number reducing with increase in impingement angle. A modified regime map is proposed to illustrate the role of impingement angle in breakup transitions. A theoretical model based on force balance at the sheet edge is developed to predict the sheet parameters by taking the shear interaction between the sheet and the solid surface into account. The sheet shape predicted by the model fairly matches with the experimentally measured sheet shape. The breakup length and width of the sheet are measured and comparisons with the model predictions show good agreement in closed rim mode of breakup.

Atomization of acoustically forced liquid sheets

2019 ◽  
Vol 880 ◽  
pp. 653-683 ◽  
Author(s):  
Sandip Dighe ◽  
Hrishikesh Gadgil
Keyword(s):  
Acoustic Field ◽  
Cutoff Frequency ◽  
Liquid Sheet ◽  
Liquid Jets ◽  
Liquid Sheets ◽  
Aerodynamic Interaction ◽  
Transverse Acoustic ◽  
External Acoustic Field ◽  
Acoustic Forcing ◽  
Sheet Breakup

Atomization of a smooth laminar liquid sheet produced by the oblique impingement of two liquid jets and subjected to transverse acoustic forcing in quiescent ambient is investigated. The acoustic forcing perturbs the liquid sheet perpendicular to its plane, thereby setting up a train of sinuous waves propagating radially outwards from the impingement point. These sheet undulations grow as the wave speed decreases towards the edge of the sheet and the sheet characteristics, like intact length and mean drop size, reduce drastically as compared to the natural breakup. Our observations show that the effect of the acoustic field is perceptible over a continuous range of forcing frequencies. Beyond a certain forcing frequency, called the cutoff frequency, the effect of the external acoustic field ceases. The cutoff frequency is found to be an increasing function of the Weber number. Our measurements of the characteristics of spatially amplifying sinuous waves show that the instabilities responsible for the natural sheet breakup augment in the presence of external forcing. Combining the experimental observations and measurements, we conclude that the linear theory of aerodynamic interaction (Squire’s theory) (Squire, Brit. J. Appl. Phys., vol. 4 (6), 1953, pp. 167–169) predicts the important features of this phenomenon reasonably well.

Breakup of a power-law liquid sheet formed by an impinging jet injector

2012 ◽  
Vol 39 ◽  
pp. 37-44 ◽  
Author(s):  
Li-jun Yang ◽  
Qing-fei Fu ◽  
Yuan-yuan Qu ◽  
Bin Gu ◽  
Meng-zheng Zhang
Keyword(s):  
Power Law ◽  
Impinging Jet ◽  
Liquid Sheet

The Effect of Crosswind Velocity on the Spray Drift of Flat Fan Nozzle

2019 ◽  
Author(s):  
S. Raza ◽  
K. A. Sallam ◽  
S. L. Post
Keyword(s):  
Liquid Sheet ◽  
Nozzle Geometry ◽  
Target Area ◽  
Spray Drift ◽  
Agricultural Industry ◽  
Injection Angle ◽  
Drift Flux ◽  
Breakup Mechanism ◽  
Primary Breakup ◽  
Sheet Breakup

Abstract The objective of this research project is to eliminate the spray drift caused by crosswind. Spray drift is an important problem for the agricultural industry. Some herbicides (e.g. Dicamba) can cause serious damage if it drifts to nearby crops that are not genetically modified to withstand those herbicides. Our hypothesis is that the nozzle geometry and the injection angle can be actively/passively controlled to compensate for the crosswind velocity and effectively deliver the herbicides to the target area. The measurements include the breakup regime transitions, the droplet sizes, and the droplets trajectory as function of the wind speed and the injection angle. The current results show that the crosswind modifies the primary breakup mechanism from sheet breakup regime (i.e. thinning and fragmentation of the liquid sheet into ligaments) to bag breakup regime (i.e. the formation bags along the downstream side of liquid sheet) resulting in smaller drop sizes and an increased drift flux. Techniques to eliminate the bag breakup regime are presented.

Experimental investigation of heat transfer of impinging jet on a roughened plate by a micro cubic shape

2019 ◽  
Vol 33 (3) ◽  
pp. 210-225 ◽  
Author(s):  
M. Attalla ◽  
Ahmed A. Abdel Samee ◽  
Naser N. Salem
Keyword(s):  
Heat Transfer ◽  
Experimental Investigation ◽  
Impinging Jet

scholarly journals Experimental investigation on the performance of an impinging jet solar air heater

2017 ◽  
Vol 56 (1) ◽  
pp. 63-69 ◽  
Author(s):  
T. Rajaseenivasan ◽  
S. Ravi Prasanth ◽  
M. Salamon Antony ◽  
K. Srithar
Keyword(s):  
Experimental Investigation ◽  
Impinging Jet ◽  
Solar Air Heater ◽  
Air Heater

scholarly journals An Experimental Study of the Effects of Liquid Properties on the Breakup of a Two-Dimensional Liquid Sheet

1990 ◽  
Author(s):  
B. E. Stapper ◽  
W. A. Sowa ◽  
G. S. Samuelsen
Keyword(s):  
Imaging System ◽  
Pulsed Laser ◽  
Liquid Sheet ◽  
Liquid Fuels ◽  
Two Dimensional ◽  
Flow Rates ◽  
Fundamental Interest ◽  
Breakup Mechanism ◽  
Sheet Breakup ◽  
Time Required

The breakup of a liquid sheet is of fundamental interest in the atomization of liquid fuels. The present study explores the breakup of a two-dimensional liquid sheet in the presence of co-flow air with emphasis on the extent to which liquid properties affect breakup. Three liquids, selected with varying values of viscosity and surface tension, are introduced through a twin-fluid, two-dimensional nozzle. A pulsed laser imaging system is used to determine the sheet structure at breakup, the distance and time to breakup, and the character of the ligaments and droplets formed. Experiments are conducted at two liquid flow rates with five flow rates of co-flowing air. Liquid properties affect the residence time required to initiate sheet breakup, and alter the time and length scales in the breakup mechanism.

An Experimental Study of the Effects of Liquid Properties on the Breakup of a Two-Dimensional Liquid Sheet

1992 ◽  
Vol 114 (1) ◽  
pp. 39-45 ◽  
Author(s):  
B. E. Stapper ◽  
W. A. Sowa ◽  
G. S. Samuelsen
Keyword(s):  
Imaging System ◽  
Pulsed Laser ◽  
Liquid Sheet ◽  
Liquid Fuels ◽  
Two Dimensional ◽  
Flow Rates ◽  
Fundamental Interest ◽  
Breakup Mechanism ◽  
Sheet Breakup ◽  
Time Required

The breakup of a liquid sheet is of fundamental interest in the atomization of liquid fuels. The present study explores the breakup of a two-dimensional liquid sheet in the presence of co-flow air with emphasis on the extent to which liquid properties affect breakup. Three liquids, selected with varying values of viscosity and surface tension, are introduced through a twin-fluid, two-dimensional nozzle. A pulsed laser imaging system is used to determine the sheet structure at breakup, the distance and time to breakup, and the character of the ligaments and droplets formed. Experiments are conducted at two liquid flow rates with five flow rates of co-flowing air. Liquid properties affect the residence time required to initiate sheet breakup, and alter the time and length scales in the breakup mechanism.

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