scholarly journals Numerical Study on Combustion and Atomization Characteristics of Coaxial Injectors for LOX/Methane Engine

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Jiabao Xu ◽  
Ping Jin ◽  
Ruizhi Li ◽  
Jue Wang ◽  
Guobiao Cai
Keyword(s):  
Weber Number ◽  
Numerical Study ◽  
Three Dimensional ◽  
Combustion Stability ◽  
Momentum Ratio ◽  
Shear Coaxial Injector ◽  
Atomization Performance ◽  
Lox Methane ◽  
Coaxial Injector ◽  
Fluid Parameters

The LOX/methane engine has an admirable performance under a supercritical state. However, the properties of methane change drastically with varying injection temperature. Because the injector can greatly affect the atomization and combustion, this study performed a three-dimensional numerical simulation of atomization, combustion, and heat transfer in a subscale LOX/methane engine to evaluate the effect of the main fluid parameters with different methane injection temperatures and different injectors on atomization performance and combustion performance. The results show that the larger propellant momentum ratio and Weber number can improve the heat flux and combustion stability in shear coaxial injector, while the influence in swirl coaxial injector is relatively small. Moreover, in shear coaxial injector and in swirl coaxial injector, the larger propellant momentum ratio and Weber number can reduce the droplet size, enhance atomization performance, and improve the combustion efficiency. The numerical model provides an economical method to evaluate the main fluid parameters and proposes new design principles of injectors in LOX/methane engine.

scholarly journals Dynamics of Single Droplet Splashing on Liquid Film by Coupling FVM with VOF

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 841
Author(s):  
Yuzhen Jin ◽  
Huang Zhou ◽  
Linhang Zhu ◽  
Zeqing Li
Keyword(s):  
Liquid Film ◽  
Weber Number ◽  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Single Droplet ◽  
Navier Stokes Equations ◽  
Volume Method ◽  
The Relationship

A three-dimensional numerical study of a single droplet splashing vertically on a liquid film is presented. The numerical method is based on the finite volume method (FVM) of Navier–Stokes equations coupled with the volume of fluid (VOF) method, and the adaptive local mesh refinement technology is adopted. It enables the liquid–gas interface to be tracked more accurately, and to be less computationally expensive. The relationship between the diameter of the free rim, the height of the crown with different numbers of collision Weber, and the thickness of the liquid film is explored. The results indicate that the crown height increases as the Weber number increases, and the diameter of the crown rim is inversely proportional to the collision Weber number. It can also be concluded that the dimensionless height of the crown decreases with the increase in the thickness of the dimensionless liquid film, which has little effect on the diameter of the crown rim during its growth.

Numerical Study on Layout of Refractory Belt and Fouling Deposition in Tangentially Fired Boiler

2016 ◽  
Author(s):  
Qiongliang Zha ◽  
Kai Chen ◽  
Jianwen Zhang ◽  
Jiangtao Li ◽  
Chang’an Wang ◽  
...  
Keyword(s):  
Surface Temperature ◽  
Numerical Investigation ◽  
Numerical Study ◽  
High Surface ◽  
Three Dimensional ◽  
Furnace Wall ◽  
Combustion Stability ◽  
Particle Capture ◽  
Dimensional Simulation ◽  
Ignition And Combustion

The refractory belt installed in primary combustion zone provides simplest and most effective solution to suppress ignition delay and enhance combustion stability for low volatile anthracite and lean coal. The fouling deposition generally formed on radiative refractory lined wall of the boiler due to a high surface temperature. The growth of deposition thickness is mainly dependent on the parcile impact on the surface of water wall. A particle capture submodel was used to determine whether a particle was captured to form deposition or not when it reached the furnace wall, and the particle capture criterion was based on the particle’s viscosity and the temperature of the furnace wall. A reduced fouling deposition model was implemented in a three dimensional simulation of a tangentially fired boiler. The numerical investigation was conducted to assess the performance of different layouts of refractory belt. Furnace temperature, surface temperature of refractory belt, and deposition distributions on the furnace wall should be taken into account when layouts of refractory belt are optimized. Based on this, three layouts of refractory belt were proposed for tangentially fired boilers. A numerical investigation was conducted to assess the performance of different layouts of refractory belt and the results showed that the temperature in furnace was increased, and the ignition and combustion processes were stabilized when refractory belts were installed. The reasonable arrangement of refractory belt could reduce the possibility of fouling deposition in furnace.

scholarly journals Numerical Simulations of the Flame of a Single Coaxial Injector

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Victor P. Zhukov ◽  
Markus Feil
Keyword(s):  
Burning Velocity ◽  
Three Dimensional ◽  
Velocity Model ◽  
Test Case ◽  
Test Cases ◽  
Ansys Cfx ◽  
Sst Model ◽  
Planar Laser ◽  
Shear Coaxial Injector ◽  
Coaxial Injector

The processes of mixing and combustion in the jet of a shear-coaxial injector are investigated. Two test cases (nonreacting and reacting) are simulated using the commercial computational fluid dynamics code ANSYS CFX. The first test case is an experiment on the mixing in a nonreacting coaxial jet carried out with the use of planar laser induced fluorescence (PLIF). The second test case is an experiment on the visualization of hydrogen-oxygen flame using PLIF of OH in a single injector combustion chamber at pressure of 53 bar. In the first test case, the two-dimensional axisymmetric simulations are performed using the shear-stress turbulence (SST) model. Due to the dominant flow unsteadiness in the second test case, the turbulence is modeled using transient SAS (Scale-Adaptive Simulation) model. The combustion is modeled using the burning velocity model (BVM) while both two- and three-dimensional simulations are carried out. The numerical model agrees with the experimental data very well in the first test case and adequately in the second test case.

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