scholarly journals Scaling spray penetration at supersonic conditions through shockwave analysis

Fuel ◽  
2020 ◽  
Vol 260 ◽  
pp. 116308 ◽  
Author(s):  
Francisco Javier Salvador ◽  
Joaquín De la Morena ◽  
Hadi Taghavifar ◽  
Arash Nemati
Keyword(s):  
Spray Penetration

Fuel Spray Trajectory in Diesel Engines

1978 ◽  
Vol 100 (2) ◽  
pp. 326-332 ◽  
Author(s):  
M. M. Elkotb ◽  
N. M. Rafat
Keyword(s):  
Heat Transfer ◽  
Theoretical Model ◽  
Working Conditions ◽  
Fuel Spray ◽  
Air Velocity ◽  
Spray Penetration ◽  
Injection Angle ◽  
Velocity Pattern ◽  
Spray Volume ◽  
Spray Velocity

A detailed investigation of the effect of the shape of an open combustion chamber for diesel engine on the air velocity pattern, and consequently, on the trajectory of the fuel spray is given in this paper. A theoretical model for the calculation of the spray penetration, taking into consideration the heat transfer to the droplet, the variation of the drag force with Reynolds number, and air velocity pattern, is suggested. The effect of some working conditions on the spray shape, trajectory, and penetration is experimentally studied to verify the theoretical model and to correlate the results of using different medium pressures, initial spray velocity, and injection angle on the magnitude of fuel spray diameter and spray volume.

Air Assisted Sprayer for Improved Spray Penetration in Greenhouse Floriculture Crops

2015 ◽  
Vol 96 (1) ◽  
pp. 1-9
Author(s):  
Sachin V. Wandkar ◽  
Shailendra M. Mathur ◽  
Kishor G. Dhande ◽  
Pravin P. Jadhav ◽  
Babasaheb S. Gholap
Keyword(s):  
Spray Penetration

A Quasi-Dimensional Fuel Distribution Model for a Radially Stratified Engine

2021 ◽  
Author(s):  
Dennis Robertson ◽  
Patrick O'Donnell ◽  
Benjamin Lawler ◽  
Robert Prucka
Keyword(s):  
Reference Model ◽  
Computation Time ◽  
Distribution Model ◽  
Strategy Development ◽  
Real Time Control ◽  
Spray Penetration ◽  
Fuel Distribution ◽  
Time Control ◽  
Fuel Stratification ◽  
Execution Speed

Abstract Several combustion strategies leverage radial fuel stratification to adapt combustion performance between the center of the chamber and the outer regions independently. Spark-assisted compression ignition (SACI) relies on careful tuning of this radial stratification to maximize the combined performance of flame propagation and autoignition. Established techniques for determining in-cylinder fuel stratification are computationally intensive, limiting their feasibility for control strategy development and real-time control. A simplified model for radial fuel stratification is developed for control-oriented objectives. The model consists of three submodels: spray penetration, fuel distribution along the spray axis, and post-injection mixing. The spray penetration model is adapted from fuel spray models presented in the literature. The fuel distribution and mixing submodels are validated against injection spray results from an LES 3-D computational fluid dynamics (CFD) reference model for three test points as a function of crank angle. The quasi-one-dimensional model matches the CFD results with a root mean square error (RMSE) for equivalence ratio of 0.08?0.11. This is a 50% reduction from the 0.16?0.20 RMSE for a model that assumes a uniform fuel distribution immediately after injection. The computation time is 230 ms on an Intel Xeon E5-1620 v3 to solve each case without significant optimization for code execution speed.

A New Validation of Spray Penetration Models for Modern Heavy Duty Diesel Fuel Injectors

2017 ◽  
Author(s):  
Russell P. Fitzgerald ◽  
Christopher Gehrke ◽  
Kenth Svensson ◽  
Glen Martin
Keyword(s):  
Diesel Fuel ◽  
Heavy Duty ◽  
Spray Penetration ◽  
Fuel Injectors ◽  
Heavy Duty Diesel

Experimental Study of Spray Penetration under High Pressure Common Rail Condition

2011 ◽  
Vol 347-353 ◽  
pp. 66-69
Author(s):  
Jian Xin Liu ◽  
Song Liu ◽  
Hui Yong Du ◽  
Zhan Cheng Wang ◽  
Bin Xu
Keyword(s):  
High Pressure ◽  
High Speed ◽  
Injection Pressure ◽  
Electronic System ◽  
Common Rail ◽  
Spray Penetration ◽  
Jet Breakup ◽  
Secondary Breakup ◽  
Breakup Time ◽  
High Pressure Common Rail

The fuel spray images were taken with an equipment (camera-flash-injection) which has been synchronized with a purpose made electronic system under the condition of the high pressure common rail in two injection pressure has been expressed in this paper. It is discovered when fitting spray tip penetration that after jet breakup for a period of time, the spray tip begin to slow down rapidly, and the speed of spray tip running becomes smooth. Hiroyasu and other traditional tip penetration fitting formula are fitting larger to this phase. This is because that after jet breakup, the secondary breakup of striker particles will occur under the influence of the aerodynamic, surface tension and viscosity force. Therefore, a spray penetration fitting formula containing secondary breakup time to fit penetration in three sections was proposed in this paper. Results show that when pressure difference increase, both first and second breakup time become earlier. The former is because of gas-liquid relative velocity increasing, while the latter is due to high speed interface movement acceleration increasing.

scholarly journals The biological effect of cage design corrected for reductions in spray penetration

2014 ◽  
Vol 54 (4) ◽  
pp. 395-400 ◽  
Author(s):  
Bradley Keith Fritz ◽  
Wesley Clint Hoffmann ◽  
Jane Annalise Sara Bonds ◽  
Keith Haas ◽  
Zbigniew Czaczyk
Keyword(s):  
Wind Tunnel ◽  
Biological Effect ◽  
Conversion Factor ◽  
Mortality Data ◽  
Data Set ◽  
Spray Penetration ◽  
Mosquito Mortality ◽  
Insect Mortality ◽  
Group Variation ◽  
Penetration Data

Abstract In-field measures of physical spray concentration do not tend to correlate well with caged insect mortality data. This is partly due to the reduced penetration of the spray into the cage. Spray penetration is hindered by the structure of the cage. Wind tunnel studies were conducted to investigate the accuracy of those calculations developed to correct for filtration levels in caged mosquito bioassays. Zenivex E20 (Etofenprox) was applied at rates ranging from an LD10 to an LD90. Three cage types were used, each with different penetration levels. The dose approaching the cage was converted to the dose entering the cage using cage penetration data from previous research. The penetration conversion factor returned a data set that directly correlated dose with mosquito mortality (R2 = = 0.918). The mortality percent was a function of the dose within the cage. The mesh type acted as a regulator. Although the conversion factor was effective, the differences between cages was not always significant due to within-group variation.

Numerical Investigation on the Effect of Advanced Breakup Model on Spray Simulation of a Multi-Hole Injector

2018 ◽  
Author(s):  
Srinibas Tripathy ◽  
Sridhar Sahoo ◽  
Dhananjay Kumar Srivastava
Keyword(s):  
Mass Fraction ◽  
Gas Pressure ◽  
Gas Jet ◽  
Computational Time ◽  
Fuel Vapor ◽  
Computational Domain ◽  
Penetration Length ◽  
Spray Penetration ◽  
Ambient Gas ◽  
Vapor Mass

Computational fluid dynamics (CFD) plays a tremendous role in evaluating and visualizing the spray breakup, atomization and vaporization process. In this study, ANSYS Forte CFD tool was used to simulate the spray penetration length and spray morphology in a constant volume chamber at different grid size of a multi-hole injector. An unsteady gas jet model was coupled with Kelvin-Helmholtz (KH) and Rayleigh-Taylor (RT) model for multi-hole spray simulation. The effect of CFD cell size and ambient gas pressure on spray penetration length and spray morphology of fuel vapor mass fraction were investigated for both KH-RT and KH-RT with the unsteady gas jet model. It is found that KH-RT with the unsteady gas jet model shows mesh independent spray penetration length and spray morphology of fuel vapor mass fraction as compared to KH-RT model. This can be explained by the Lagrangian-Eulerian coupling of axial droplet-gas relative velocity is modeled on the principle of unsteady gas jet theory instead of discretizing very fine grid to the computational domain. This reduces the requirement of fine mesh near the nozzle and allows larger time step during spray injection. It is also observed that at higher ambient gas pressure, an aerodynamic force between the droplet and gas intensifies which reduces the overall spray penetration length and fuel vapor mass. The distorted spray morphology of fuel vapor mass fraction was accurately predicted at high ambient gas pressure using the KH-RT with an unsteady gas jet model which results in mesh independent drag predictions. The use of advanced spray model results in the mesh size dependency reduction and accurate drag prediction with less computational time and faster accurate solutions over all conventional spray breakup models.

Sign in / Sign up

Export Citation Format

Share Document