scholarly journals The malfunction of a double-base propellant gas generator

2020 ◽  
pp. 92-98
Author(s):  
Rafał Bogusz ◽  
Tomasz Wolszakiewicz
Keyword(s):  
Combustion Chamber ◽  
Gas Generator ◽  
Combustion Chambers ◽  
Ballistic Tests ◽  
Failure Conditions ◽  
Double Base ◽  
Base Gas

The paper presents results of research aimed at determining the cause leading to the malfunction of a double base gas generator. For the purposes of this work, gas generator charges and combustion chambers were intentionally damaged in order to replicate failure conditions. Damage to the inhibitor covering the gas generator and contamination in the combustion chamber, was simulated. The damaged charges and chambers were subjected to ballistic tests.

scholarly journals Modeling of Spray Combustion with a Steady Laminar Flamelet Model in an Aeroengine Combustion Chamber Based on OpenFOAM

2018 ◽  
Vol 2018 ◽  
pp. 1-13
Author(s):  
Yinli Xiao ◽  
Zupeng Wang ◽  
Zhengxin Lai ◽  
Wenyan Song
Keyword(s):  
Combustion Chamber ◽  
High Performance ◽  
Numerical Models ◽  
Spray Combustion ◽  
Combustion Chambers ◽  
Flamelet Model ◽  
Steady Laminar ◽  
Good Agreement ◽  
Laminar Flamelet ◽  
Laminar Flamelet Model

The development of high-performance aeroengine combustion chambers strongly depends on the accuracy and reliability of efficient numerical models. In the present work, a reacting solver with a steady laminar flamelet model and spray model has been developed in OpenFOAM and the solver details are presented. The solver is firstly validated by Sandia/ETH-Zurich flames. Furthermore, it is used to simulate nonpremixed kerosene/air spray combustion in an aeroengine combustion chamber with the RANS method. A comparison with available experimental data shows good agreement and validates the capability of the new developed solver in OpenFOAM.

A General Rezoning Technique for KIVA3V Internal Combustion Engines CFD Simulations

2010 ◽  
Author(s):  
Randy P. Hessel ◽  
Ettore Musu ◽  
Salvador M. Aceves ◽  
Daniel L. Flowers
Keyword(s):  
Combustion Chamber ◽  
Internal Combustion Engines ◽  
Ad Hoc ◽  
National Laboratory ◽  
Internal Combustion ◽  
Computational Time ◽  
Combustion Engines ◽  
Combustion Chambers ◽  
Time Step ◽  
Engine Cycle

A computational mesh is required when performing CFD-combustion modeling of internal combustion engines. For combustion chambers with moving pistons and valves, like those in typical cars and trucks, the combustion chamber shape changes continually in response to piston and valve motion. The combustion chamber mesh must then also change at each time step to reflect that change in geometry. The method of changing the mesh from one computational time step to the next is called rezoning. This paper introduces a new method of mesh rezoning for the KIVA3V CFD-combustion program. The standard KIVA3V code from Los Alamos National Laboratory comes with standard rezoners that very nicely handle mesh motion for combustion chambers whose mesh does not include valves and for those with flat heads employing vertical valves. For pent-roof and wedge-roof designs KIVA3V offers three rezoners to choose from, the choice depending on how similar a combustion chamber is to the sample combustion chambers that come with KIVA3V. Often, the rezoners must be modified for meshes of new combustion chamber geometries to allow the mesh to successfully capture change in geometry during the full engine cycle without errors. There is no formal way to approach these modifications; typically this requires a long trial and error process to get a mesh to work for a full engine cycle. The benefit of the new rezoner is that it replaces the three existing rezoners for canted valve configurations with a single rezoner and has much greater stability, so the need for ad hoc modifications of the rezoner is greatly reduced. This paper explains how the new rezoner works and gives examples of its use.

Numerical Investigation of the Influence of Flow Parameters Nonuniformity at the Diffuser Inlet on Characteristics of the GTE Annular Combustion Chamber

2015 ◽  
Author(s):  
Sergey S. Matveev ◽  
Ivan A. Zubrilin ◽  
Mikhail Yu. Orlov ◽  
Sergey G. Matveev
Keyword(s):  
Combustion Chamber ◽  
Dynamic Pressure ◽  
Air Distribution ◽  
Gas Generator ◽  
Air Velocity ◽  
Degree Polynomial ◽  
Flow Dynamic ◽  
Ansys Fluent ◽  
Flow Parameters ◽  
Mode Of Operation

Parameters at a combustion chamber’s inlet significantly vary in an aircraft engine’s transient states of operation. At the same time, there is a significant spatial heterogeneity of flow parameters at a diffuser inlet of a combustion chamber, which is defined by nature of flow in a compressor and an individual for each mode of operation of a specific gas generator. In this paper presented a study of an influence of radial and circumferential nonuniformities of flow parameters on characteristics of a combustion chamber. Multi spray for annular combustion chamber with two rows of burner is considered. Z-shaped sector, which contains two nozzles of outer and two nozzles of inner row, was selected as the calculated domain. Calculations were carried out in ANSYS Fluent 14.5 software package with an implementation of cluster analysis. Nonuniformity at a diffuser inlet was set as fifth degree polynomial, which was derived from a numerical simulation of a compressor. As a result it was established, that radial nonuniformity of flow parameters at an inlet of a combustion chamber influences on characteristics of a combustion chamber. A stretched shape of velocity profile contributes to higher air flow dynamic pressure on dome than using uniform profile air velocity. At that, local equivalents ratio excess are changing, and consequently, sizes and location NOx production zones are changing as well. The residual rotation of flow from the compressor leads to a lesser effect on total pressure drop and air distribution in flame tube. The obtained results showed that, during a design of a combustion chamber, it is necessary to take into account nonuniformity of parameters’ distribution at its inlet.

A Novel Gas Generator Concept for Jet Engines Using a Rotating Combustion Chamber

2013 ◽  
Author(s):  
Peter Jeschke ◽  
Andreas Penkner
Keyword(s):  
Combustion Chamber ◽  
Weight Ratio ◽  
Thermodynamic Cycle ◽  
Ceramic Materials ◽  
Single Stage ◽  
Jet Engines ◽  
Gas Generator ◽  
Small Core ◽  
Efficiency Increase ◽  
Flow Compressor

A gas generator — consisting of a single-stage shrouded mixed-flow compressor without a diffusor, a rotating combustion chamber, and a vaneless single-stage shrouded centripetal turbine — is presented and analyzed here. All components comprise a coherent rotating device, which avoids most of the problems usually associated with small gas generators. In other words, the concept avoids all radial clearances, it is vaneless, shortens the combustion chamber, minimizes the wetted area and enables ceramic materials to be used, due to compressive blade stresses. However, the concept faces severe structural, thermal and chemical reaction challenges. All these features and their implications are discussed and their benefits for several jet engines are quantified, mainly by means of thermodynamic cycle calculations. An upfront CFD analysis identifies a polytropic compressor efficiency of around 95%. It is then demonstrated that the concept offers a thrust-to-weight ratio which is several times higher than the standard when incorporated into small UAV-type jet engines. It also enables an attractive multistage and dual-flow, but fully vaneless design option. Lastly, a thermal efficiency increase of several percentage points would be achieved, if the concept were to be realized in the (small) core of turbofans with highest overall pressure ratios and high bypass ratios. In summary, the paper presents a gas generator approach which may be considered by designers of small jet engines like those used in UAV applications and it might even be a (challenging) long-term option for the small core engines encountered in future turbofans and turboprops.

scholarly journals Igniting Soaring Droplets of Promising Fuel Slurries

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 208 ◽  
Author(s):  
Alexander Bogomolov ◽  
Timur Valiullin ◽  
Ksenia Vershinina ◽  
Sergey Shevyrev ◽  
Nikita Shlegel
Keyword(s):  
Combustion Chamber ◽  
Power Plants ◽  
Alternative Fuels ◽  
Complex Geometry ◽  
Thermal Power ◽  
Combustion Chambers ◽  
Fuel Droplets ◽  
Fine Coal ◽  
Active Research ◽  
Burning Coal

High rates of environmental pollution by boilers and thermal power plants burning coal of different grades are the main reason for active research in the world aimed at the development of alternative fuels. The solution to the formulated problem acceptable in terms of environmental, technical and economic criteria is the creation of composite slurry fuels with the use of fine coal or coal processing and enrichment waste, water of different quality, and oil sludge additive. This study considers modern technologies of burning slurry fuels as well as perspective research methods of the corresponding processes. A model combustion chamber is developed for the adequate study of ignition processes. The calculation of the basic geometric dimensions is presented. The necessity of manufacturing the combustion chamber in the form of an object of complex geometry is substantiated. With its use, several typical modes of slurry fuel ignition are determined. Principal differences of ignition conditions of a single droplet and group of fuel droplets are shown. Typical vortex structures at the fuel spray injection are shown. A comparison with the trajectories of fuel aerosol droplets in real combustion chambers used for the combustion of slurry fuels is undertaken.

Simulation Research on Matching of Spray and Combustion Chamber Geometry in Diesel Engine

2011 ◽  
Vol 199-200 ◽  
pp. 193-197 ◽  
Author(s):  
Cheng Cheng Zhang ◽  
Qian Wang ◽  
Zhi Xia He ◽  
Ping Jiang
Keyword(s):  
Temperature Field ◽  
Diesel Engine ◽  
Combustion Chamber ◽  
Shape Change ◽  
Emission Characteristics ◽  
Mixed Gas ◽  
Combustion Chambers ◽  
Simulation Research ◽  
Different Types ◽  
Combustion Processes

In order to investigate the influence of combustion chamber geometry on spray and combustion characteristics in diesel engine, universal CFD software STAR-CD is applied to simulate the combustion processes in three different types of combustion chambers of diesel engine. The effect of combustion chamber geometry on in–cylinder air motion, temperature field and exhaust emissions are researched in this paper. Comparing with experimental results, calculation models are proved to be validity. The results show that differences of combustion chamber shape change the characteristic of flow field in cylinder, which affects the formation of mixed gas and determines the combustion and emission characteristics.

Prediction of the Thermoacoustic Combustion Instabilities in Practical Annular Combustors

2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Giovanni Campa ◽  
Sergio Mario Camporeale
Keyword(s):  
Combustion Chamber ◽  
Three Dimensional ◽  
Design Stage ◽  
Combustion Instabilities ◽  
Combustion Chambers ◽  
Stability Maps ◽  
Dimensional Finite Element ◽  
Practical Tool ◽  
The Stability ◽  
Three Dimensional Finite Element

A three-dimensional finite element code is used for the eigenvalue analysis of the thermoacoustic combustion instabilities modeled through the Helmholtz equation. A full annular combustion chamber, equipped with several burners, is examined. Spatial distributions for the heat release intensity and for the time delay are used for the linear flame model. Burners, connecting the plenum and the chamber, are modeled by means of the transfer matrix method. The influence of the parameters characterizing the burners and the flame on the stability levels of each mode of the system is investigated. The obtained results show the influence of the 3D distribution of the flame on the modes. Additionally, the results show what types of modes are most likely to yield humming in an annular combustion chamber. The proposed methodology is intended to be a practical tool for the interpretation of the thermoacoustic phenomenon (in terms of modes, frequencies, and stability maps) both in the design stage and in the check stage of gas turbine combustion chambers.

scholarly journals Numerical and Experimental Analysis of Heat Transfer for Solid Fuels Combustion in Fixed Bed Conditions

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6141
Author(s):  
Wojciech Judt
Keyword(s):  
Heat Transfer ◽  
Combustion Chamber ◽  
Transfer Process ◽  
Heat Load ◽  
Fixed Bed ◽  
Heat Transfer Process ◽  
Biomass Combustion ◽  
Solid Fuels ◽  
Hard Coal ◽  
Combustion Chambers

The paper concerns the analysis of the heat transfer process that occurred during solid fuel burning in fixed bed conditions. The subject of the analysis is a cylindrical combustion chamber with an output of 12 kW heating power equipped with a retort burner for hard coal and biomass combustion. During the research, a numerical and experimental study is performed. The analysis is prepared for various heat load of the combustion chamber, which allowed for the reconstruction of real working conditions for heating devices working with solid fuels combustion. The temperature distribution obtained by the experimental way is compared with results of the numerical modeling. Local distribution of principal heat transfer magnitudes like a heat flux density and a heat transfer coefficient that occurred on the sidewall of the combustion chamber is analyzed. The analysis showed, that the participation of convection and radiation in the overall heat transfer process has resulted from the heat load of the heating device. Research results may be used for improving an analytical approach of design process taking place for domestic and industrial combustion chambers.

Research on Parametric Design Method of Combustion Chamber on Diesel Engine

2011 ◽  
Vol 383-390 ◽  
pp. 1431-1440
Author(s):  
Yong Shang ◽  
Fu Shui Liu ◽  
Xiang Rong Li ◽  
Jing Wu
Keyword(s):  
Diesel Engine ◽  
Combustion Chamber ◽  
Calculation Result ◽  
Parametric Design ◽  
Design Method ◽  
Geometrical Parameters ◽  
Combustion Chambers ◽  
Heat Efficiency ◽  
Swirl Combustion ◽  
Combustion Duration

One method of parametric design on combustion chamber is used in this paper. Several independent geometrical parameters of ω type and double swirl combustion chamber are brought forward. Different series of ω type and double swirl combustion chambers have been designed by using this method. The effect of the independent geometrical parameters on the performance of diesel engine has been studied by using CFD code AVL FIRE. According to this method of parametric design and calculation result, two pistons with ω type and double swirl combustion chamber has been designed with the target of the highest indicated heat efficiency. The test result shows that, contrasting with ω type chamber, BSFC and main combustion duration of double swirl combustion chamber is lower by 7.5 and 6.9 percent respectively, while indicated heat efficiency is 7.1 percent higher. And the calculation result has coherence with the experiment. It is proved that the method of parametric design on combustion chamber can satisfy the requirement of designing. At the same time, this method can be extended to design other combustion chambers.

Sign in / Sign up

Export Citation Format

Share Document