scholarly journals Research on Distribution Properties of Coating Film Thickness from Air Spraying Gun-Based on Numerical Simulation

Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 721 ◽  
Author(s):  
Xiaopeng Xie ◽  
Yinan Wang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Film Thickness ◽  
Coating Thickness ◽  
Thickness Distribution ◽  
Air Pressure ◽  
Reasonable Assumption ◽  
Coating Film ◽  
Discrete Phase Model ◽  
Spraying Process

This work aims to study the influence of the spraying parameters on the spray flow field and coating thickness distribution during the air spraying process. The shaping air pressure and the target geometry have an important influence on the distribution of coating film thickness. This paper begins with a 3-D physical model of an air spray gun, in which unstructured grids were generated for control domain. A grid independency study was also carried out to determine the optimal number of cells for the simulations. Then the Euler–Lagrange method was used to describe the two-phase spray flow by establishing a paint deposition model. The numerical simulation based on the discrete phase model (DPM) and TAB model has been carried out. A reasonable assumption was proposed based on the analysis of the spraying process, so that the droplets were injected into the airflow at the position of the paint hole. The influence of the shaping air pressure on the air flow field and the coating thickness distribution was analyzed by changing the shaping air pressure. From the numerical simulation results, it can be concluded that the smaller the shaping air pressure, the more concentrated the coating. With increasing the shaping air pressure, the length of the coating film along z-axis gradually increases, the width along x-axis gradually decreases, and the spray area gradually increases. The paper ends with a numerical simulation and experimental study on planar vertical spraying, planar tilted spraying, and cylinder spraying. Comparisons and experiment results verify the validity and practicability of the model built in this paper.

scholarly journals Design of a Double-Nozzle Air Spray Gun and Numerical Research in the Interference Spray Flow Field

Coatings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 475
Author(s):  
Yin-An Wang ◽  
Xiao-Peng Xie ◽  
Xiao-Hui Lu
Keyword(s):  
Flow Field ◽  
Central Region ◽  
Interference Effect ◽  
Thickness Distribution ◽  
Computational Domain ◽  
Coating Film ◽  
Discrete Phase Model ◽  
Spray Painting ◽  
Flow Field Characteristics ◽  
Spray Gun

Spray painting robots equipped with air spray guns have been widely used in the painting industry. In view of the low efficiency of single-nozzle air spray guns when spraying large targets, a new double-nozzle air spray gun structure was designed in this paper based on the Coanda effect of double jets. Firstly, a 3-D physical model of the double-nozzle air spray gun was built in Solidworks, in which unstructured grids were generated for the computational domain by ICEM. Secondly, the spray painting process was numerically modeled with the help of the computational fluid dynamics (CFD) software ANSYS-Fluent 16.0. The two-phase spray flow was calculated by coupling a discrete phase model (DPM) and the Taylor analogy breakup (TAB) method. The TAB model was applied to predict the secondary break-up. The DPM model was applied to predict the droplet trajectories. The geometry of an air spray gun has a significant influence on the spray flow field characteristics. The influence of the air spray gun geometry on the interference spray flow field characteristics and coating film thickness distribution were investigated by changing the values of the distance between the centers of the two paint holes (L) and the angle between the axes of the two paint holes (θ). Numerical results show that the smaller L and θ are, the stronger the interference effect between the two jets, while the more concentrated the paint is in the central region of the target surface, the easier it is for overspray to occur. With increasing L and θ, the interference effect gradually decreased and the extension distance of the coating film along the x-axis gradually increased. However, if L and θ are too large, the interference effect will become too weak and the shape of the coating film will become a concave, with more paint on both side regions and less paint in the central region, which will cause an uneven coating film. From the simulation results, it can be concluded that a more uniform coating film can be obtained when L = 30 mm and θ = 10°. The effective coating width of the double-nozzle air spray gun was increased by 85.7% compared with the single-nozzle air spray gun, which improved the spraying efficiency.

Numerical Simulation of Flow Field in a Quench Oil Tower

2007 ◽  
Author(s):  
Shuihua Zheng ◽  
Shengchang Zhang ◽  
Zengliang Gao
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Flow Field ◽  
Petrochemical Industry ◽  
Flow Distribution ◽  
Discrete Phase Model ◽  
Wide Range ◽  
Modification Method ◽  
Discrete Phase ◽  
Cfd Method

Towers are applied in the wide range of the petrochemical industry. The flow condition and the temperature distribution in the tower are the focus of the people’s attention, which would affect function of the tower and could result in unstable operation of the tower. In this paper, the flow field in a quench oil tower is simulated based on CFD method. The DPM (Discrete Phase Model) is used to calculate and analyze flow distribution and heat transfer between gas and liquid. The numerical results such as temperature and velocity distributions below lower tray in tower are obtained. According to CFD results, modification method of improving the flow distribution is proposed.

scholarly journals A Modified Equation for Thickness of the Film Fabricated by Spin Coating

Symmetry ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1183 ◽  
Author(s):  
Un Gi Lee ◽  
Woo-Byoung Kim ◽  
Do Hyung Han ◽  
Hyun Soo Chung
Keyword(s):  
Angular Velocity ◽  
Film Thickness ◽  
Newtonian Fluid ◽  
Coating Thickness ◽  
Spin Coating ◽  
Newtonian Fluids ◽  
Coating Film ◽  
Fluid Equation ◽  
Coating Time ◽  
New Formula

According to the equation for Newtonian fluids, the film thickness after spin coating is determined by five parameters: angular velocity, spin coating time, viscosity, density of the coating material, and initial thickness of the material before spin coating. The spin coating process is commonly controlled by adjusting only the angular velocity parameter and the coating time in the Newtonian expression. However, the measured coating thickness obtained is then compared to the theoretical thickness calculated from the Newtonian fluid equation. The measured coating thickness usually varies somewhat from the theoretical thickness; further details are described in Section 1. Thus, the Newtonian fluid equation must be modified to better represent the actual film thickness. In this paper, we derive a new formula for the spin coating film thickness, which is based on the equation for Newtonian fluids, but modified to better represent film thicknesses obtained experimentally. The statistical analysis is performed to verify our modifications.

Numerical Simulation of Scouring Erosion Characteristics for Electric Submersible Pump Impeller

2013 ◽  
Vol 749 ◽  
pp. 535-539 ◽  
Author(s):  
Si Chen ◽  
Zun Ce Wang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Geometric Model ◽  
Water Injection ◽  
Oil Field ◽  
Submersible Pump ◽  
Discrete Phase Model ◽  
Pump Impeller ◽  
Cutting Model ◽  
Electric Submersible Pump

This paper shows the numerical simulation of the problem that electrical submersible pump impeller is vulnerable to particle impact erosion in the water under the condition of the water injection of the same wells in oil field. This simulation is based on Fluent of CFD software, which has built a geometric model of electric submersible pump impeller flow field, and given the calculation of the internal flow field of the impeller, and showed the solution of the motion track of the particles in the turbulent by the way of discrete phase model and random orbit, and calculated the erosion by the micro cutting model by particless, and compared the field test data with the simulation results which proved the reliability of numerical simulation method.

Simulation of the Flow Parameters of the Multi-Microchannel Aerostatic Restrictor

2012 ◽  
Vol 241-244 ◽  
pp. 1278-1284
Author(s):  
Yu Bing Zhang ◽  
Cai Qin Li ◽  
Dong Sheng Li
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Film Thickness ◽  
Three Dimensional ◽  
Simulation Method ◽  
Gas Pressure ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Flow Parameters ◽  
Numerical Simulation Method

A numerical simulation method, FLUENT,has been selected to simulate the flow field parameters of the multi-microchannel aerostatic restrictor. Pressure, temperature and velocity distributions of the restrictor under different gas film thickness and gas pressure were got and compared. Used Pro / E to establish three-dimensional model of restrictor and imported it into GAMBIT for meshing, and then used FLUENT for simulation.

Numerical Simulation for Two-Phase Flow Field of FGD Scrubber in Ship

2013 ◽  
Vol 739 ◽  
pp. 450-453
Author(s):  
Yong Zheng Gu ◽  
Zhi Feng Dong ◽  
Quan Jin Kuang ◽  
Jie Liu ◽  
Yu Zhao Zhang
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Optimization Design ◽  
Two Phase Flow ◽  
Three Dimensional ◽  
Simple Algorithm ◽  
Phase Flow ◽  
Discrete Phase Model ◽  
Two Phase ◽  
Discrete Phase

Discrete phase model was used for three-dimensional numerical simulation of two-phase flow in the ship FGD scrubber. The κ-ε model and SIMPLE algorithm were adopted in the calculation. The results showed that adding porous baffles improved the distribution of flow field in the scrubber. The gas velocity in the scrubber became uniformity and the flue gas resistance decreased when the sprays worked. Under the action of the spray, the differential pressure of spray area changed greatly. The simulation plays a certain role in guiding the structural optimization design of scrubber.

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