Supersonic Combustion Processes in a Premixed Three-Dimensional Nonuniform-Compression Scramjet Engine

AIAA Journal ◽  
2014 ◽  
Vol 52 (8) ◽  
pp. 1670-1685 ◽  
Author(s):  
Mathew G. Bricalli ◽  
Laurie M. Brown ◽  
Russell R. Boyce
Keyword(s):  
Three Dimensional ◽  
Supersonic Combustion ◽  
Scramjet Engine ◽  
Combustion Processes

Simulation of Supersonic Combustion in Three-Dimensional Configurations

2009 ◽  
Vol 25 (6) ◽  
pp. 1233-1239 ◽  
Author(s):  
P. G. Keistler ◽  
H. A. Hassan ◽  
X. Xiao
Keyword(s):  
Three Dimensional ◽  
Supersonic Combustion

Simulation of Pollutant Emissions in a Small-Sized Combustion Chamber With a Gas Fuel for Various Regime Modes

2019 ◽  
Author(s):  
Nikita I. Gurakov ◽  
Ivan A. Zubrilin ◽  
Ivan V. Chechet ◽  
Vladislav M. Anisimov ◽  
Sergey S. Matveev ◽  
...  
Keyword(s):  
Experimental Data ◽  
Combustion Chamber ◽  
Equivalence Ratio ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Combustion Products ◽  
Pollutant Emissions ◽  
Eddy Simulation ◽  
Flamelet Generated Manifold ◽  
Combustion Processes

Abstract The study shows the results of the emission simulation in a small-sized combustion chamber. The influence of temperature and equivalence ratio on CO and CxHy in the combustion chamber was investigated. Experiments and calculations were carried out for the following modes: temperature at the inlet of the combustion chamber Tinlet = 323 ... 523 K; equivalence ratio φ = 0.2 ... 0.33; normalized flow rate at the inlet of the combustion chamber λ = 0.1 ... 0.3. The simulation of combustion of natural gas was carried out. The studies were conducted using CFD software and experimental methods. Measurements of the combustion products composition were carried out by the method of sampling collection and subsequent chromatographic analysis. The flow and combustion processes were simulated in a three-dimensional steady formulation using the Reynolds-averaged Novier-Stokes equations (RANS) and in a transient formulation using the Large Eddy Simulation (LES) method. The combustion processes were simulated by Flamelet Generated Manifold model in conjunction with the probability density function method (PDF). In addition to the above methods, the method of the reactor network model (RNM) was used to simulate the emission. As a result, a comparison of the calculated and experimental data of concentrations values of combustion products and emissions indices averaged over the combustion chamber outlet was conducted. According to the results of the calculated-experimental study obtained: - the simulated concentrations values of the main combustion products such as CO2 and H2O qualitatively and quantitatively coincide with the experimental data (the discrepancy is less than 5%) for all three approaches — RANS, LES, RNM; - when modeling CO emissions, the discrepancy between the calculated emission indices obtained by the RANS and LES methods is greatly underestimated relative to the experimental data, whereas the values calculated by the RNM method deviate from the experiment by less than 10%; - mass concentration values of unburned hydrocarbons obtained by the RANS method are overestimated relative to the experimental values, while using the LES with RNM methods, the discrepancy does not exceed 10%.

Simulation Study on Different Composition Fuels in Lean-Burn CNG Engine

2013 ◽  
Vol 448-453 ◽  
pp. 3430-3433
Author(s):  
Chang Qing Song ◽  
Jun Li ◽  
Da Wei Qu ◽  
Qi Jie Liu
Keyword(s):  
Three Dimensional ◽  
Hydrocarbon Fuel ◽  
Simulation Software ◽  
Combustion Model ◽  
Lean Burn ◽  
Maximum Heat ◽  
Cng Engine ◽  
Valve Opening ◽  
Dimensional Simulation ◽  
Combustion Processes

The Paper has Established a Combustion Model of Lean-Burn CNG Engine by Three-Dimensional Simulation Software AVL FRIE. Based on Test Validation in the Model, the Combustion Processes of Seven CNG Samples were Simulated and Compared from the Intake Valve Closed to the Exhaust Valve Opening. the Effects on Different Composition Fuels for CNG Engine were Researched. the Results Showed that: the Maximum Average Pressure within the Cylinder , the Highest Average Temperature, the Maximum Heat Release Rate, the Initial Mass Fraction of Fuels, CO and NO Formation Increased with the Hydrocarbon Fuel Ratio C/H, the Composition of Heavy Paraffin in CNG Directly Affected the Performance and Service Life of the Engine.

Three Dimensional Thermoacoustic Oscillation in a Premix Combustor

2001 ◽  
Author(s):  
S. Akamatsu ◽  
A. P. Dowling
Keyword(s):  
Boundary Conditions ◽  
Acoustic Waves ◽  
Linear Equations ◽  
Three Dimensional ◽  
Total System ◽  
Mean Flow ◽  
Modal Coupling ◽  
Rate Of Heat Release ◽  
Flow Through ◽  
Combustion Processes

A theory is developed to describe high frequency three-dimensional thermoacoustic waves in a simplified geometry representing a typical premix combustor. The theory considers linear modes of frequency ω and circumferential mode number m i.e. proportional to eiωt+imθ. The radial and axial dependence is determined for a cylindrical combustor. Simple geometries are investigated systematically to analyze the effect of different inlet boundary conditions to the combustion chamber on the frequency of oscillation and on the susceptibility to instability, both near and away from the cut-off frequencies. The model includes a one-dimensional mean flow, radial mode coupling and idealized combustion processes, which are added in stages to build up an understanding of the complicated acoustics of the premix combustor geometry. It is demonstrated that the flow through the premix ducts provides a frequency-dependent boundary condition at combustor inlet and causes modal coupling. Generalized linear equations of conservation of mass, momentum and energy, together with boundary conditions, are solved to identify the eigenfrequencies, ω, of the total system. Then Real ω determines the frequency of the oscillation, while Imaginary ω indicates the growth rate of the disturbance. It is found that strong resonant peaks in the pressure waves exist close to the cut-off condition for acoustic waves and that the relationship between the unsteady rate of heat release and the flow significantly influences the instability of oscillation.

Numerical analysis of three-dimensional effects in unsteady supersonic combustion

1997 ◽  
Author(s):  
M. Kallenberg ◽  
E. von Lavante ◽  
M. Kallenberg ◽  
E. von Lavante
Keyword(s):  
Numerical Analysis ◽  
Three Dimensional ◽  
Supersonic Combustion ◽  
Dimensional Effects
Sign in / Sign up

Export Citation Format

Share Document