Prediction and Analysis of Combustion Chamber Thermal Load of Heavy Vehicle at Different Altitudes

2013 ◽  
Vol 706-708 ◽  
pp. 1492-1495
Author(s):  
Xian Cheng Wang ◽  
Jun Biao Hu ◽  
Xing He ◽  
Meng Chao Guo
Keyword(s):  
Combustion Chamber ◽  
Thermal Load ◽  
Predictive Ability ◽  
Combustion Model ◽  
Heavy Vehicle ◽  
Turbocharged Diesel Engine ◽  
Engine Model ◽  
Chamber Temperature ◽  
Relative Errors ◽  
Different Altitudes

For the thermal load of a heavy vehicle is too high in plateau environment, based on Hiroyasu spray model and predictive combustion model, a turbocharged diesel engine model with environmental adaptive predictive ability was established. The experimental results of 3700m revealed that the simulation result relative errors were less than 5%. The research of combustion chamber temperature field was made. This method provides a fundamental basis for further design of the combustion chamber.

A control-oriented combustion model for a turbulent jet ignition engine using liquid fuel

2017 ◽  
Vol 19 (8) ◽  
pp. 813-826 ◽  
Author(s):  
Ruitao Song ◽  
Ravi Teja Vedula ◽  
Guoming Zhu ◽  
Harold Schock
Keyword(s):  
Experimental Data ◽  
Liquid Fuel ◽  
Control Strategies ◽  
Turbulent Jet ◽  
Combustion Model ◽  
Operational Conditions ◽  
Engine Model ◽  
Model Based ◽  
Indicated Mean Effective Pressure ◽  
Relative Errors

A control-oriented engine model is necessary for developing and validating the associated engine control strategies. For engines equipped with the turbulent jet ignition system, the interaction between the pre- and main-combustion chambers should be considered in the control-oriented model for model-based control strategies that optimize the overall thermal efficiency in real-time. Therefore, a two-zone combustion model based on the newly proposed parameter-varying Wiebe function is proposed. Since the engine uses the liquid fuel, a pre-chamber air–fuel mixing and vaporization model are also developed. The model was validated using the experimental data from a single-cylinder turbulent jet ignition engine under different operational conditions, and the simulation results show a good agreement with the experimental data. The relative simulation error of the in-cylinder pressure is less than 8%. For most of the other pressure-related variables, such as indicated mean effective pressure and main-chamber burn duration, the relative errors are within 5%.

Design Analysis of a Micro Gas Turbine Combustion Chamber Burning Natural Gas

2012 ◽  
Author(s):  
André Perpignan V. de Campos ◽  
Fernando L. Sacomano Filho ◽  
Guenther C. Krieger Filho
Keyword(s):  
Experimental Data ◽  
Natural Gas ◽  
Combustion Chamber ◽  
Gas Turbines ◽  
Low Cost ◽  
Mixture Fraction ◽  
Combustion Model ◽  
Inlet Temperature ◽  
Gas Combustion ◽  
Micro Turbine

Gas turbines are reliable energy conversion systems since they are able to operate with variable fuels and independently from seasonal natural changes. Within that reality, micro gas turbines have been increasing the importance of its usage on the onsite generation. Comparatively, less research has been done, leaving more room for improvements in this class of gas turbines. Focusing on the study of a flexible micro turbine set, this work is part of the development of a low cost electric generation micro turbine, which is capable of burning natural gas, LPG and ethanol. It is composed of an originally automotive turbocompressor, a combustion chamber specifically designed for this application, as well as a single stage axial power turbine. The combustion chamber is a reversed flow type and has a swirl stabilized combustor. This paper is dedicated to the diagnosis of the natural gas combustion in this chamber using computational fluid dynamics techniques compared to measured experimental data of temperature inside the combustion chamber. The study emphasizes the near inner wall temperature, turbine inlet temperature and dilution holes effectiveness. The calculation was conducted with the Reynolds Stress turbulence model coupled with the conventional β-PDF equilibrium along with mixture fraction transport combustion model. Thermal radiation was also considered. Reasonable agreement between experimental data and computational simulations was achieved, providing confidence on the phenomena observed on the simulations, which enabled the design improvement suggestions and analysis included in this work.

CFD Analysis of the Combustion Chamber of a Commercial Aircraft Engine of Medium Thrust Class From a Maintenance Perspective

2017 ◽  
Author(s):  
Stefan Kuntzagk ◽  
Jörn Kraft ◽  
Ina Esemann
Keyword(s):  
Combustion Chamber ◽  
Temperature Profile ◽  
Measurement Errors ◽  
Burning Velocity ◽  
Combustion Model ◽  
Cfd Analysis ◽  
Hexahedral Mesh ◽  
Flow Topology ◽  
Geometrical Features ◽  
Exit Temperature

The combustion chamber of aircraft engines plays an important role in achieving the optimum performance during an engine overhaul. For long decades, it has been common understanding in the MRO business that a well overhauled compressor and turbine are required to get an engine with low SFC and high EGT margin. In recent work at Lufthansa Technik AG, a comprehensive CFD analysis of the combustion chamber showed that, in contrast to this, small geometrical features influence the mixing process in the combustion chamber and can have an effect on the exit temperature profile. This in turn can reduce the accuracy of the EGT measurement significantly and create measurement errors and misinterpretations of the real engine performance. In order to get insight into the flow topology, a very detailed digital model has been created using scans of the hardware available in the shop. Important geometrical features such as the cooling provisions and swirl creating components have been included in a very detailed manner with an efficient hexahedral mesh. The model includes the HPT vanes and the cooling flow extraction from the secondary cold flow. CFD results have been generated using the flow solver Ansys CFX 17.1, which is able to predict all relevant physical effects such as injection of liquid fuel, evaporation, and combustion of Jet A1 fuel using the Burning-Velocity combustion model. The flow in the combustion chamber shows large natural fluctuations. Subsequently, for each case a transient calculation has been carried out in order to allow an evaluation of the time-averaged flow field. Different geometrical features are investigated to predict the effect of geometry deviations on the exit temperature profile, e.g. the shape and size of the dilution holes. Finally along the example of two CFM56 engines it will be shown how the data obtained by the detailed CFD model is used to optimize work-scoping and maintenance procedures. On the two cases put forward the combination of extended test-cell instrumentation and detailed modeling enabled not only the identification but also the rectification of combustion chamber deviations. This in turn minimized the necessary work, whereas in the past combustion chamber issues often went unnoticed and consequently resulted in extensive additional work.

Simulation of a Single Cylinder Diesel Engine Under Cold Start Conditions Using Simulink

2000 ◽  
Vol 123 (1) ◽  
pp. 117-124 ◽  
Author(s):  
H.-Q. Liu ◽  
N. G. Chalhoub ◽  
N. Henein
Keyword(s):  
Diesel Engine ◽  
Direct Injection ◽  
Cold Start ◽  
Operating Conditions ◽  
Combustion Model ◽  
Nonlinear Dynamic Model ◽  
Single Cylinder ◽  
Engine Model ◽  
Simulink Model ◽  
Engine Components

A nonlinear dynamic model is developed in this study to simulate the overall performance of a naturally aspirated, single cylinder, four-stroke, direct injection diesel engine under cold start and fully warmed-up conditions. The model considers the filling and emptying processes of the cylinder, blowby, intake, and exhaust manifolds. A single zone combustion model is implemented and the heat transfer in the cylinder, intake, and exhaust manifolds are accounted for. Moreover, the derivations include the dynamics of the crank-slider mechanism and employ an empirical model to estimate the instantaneous frictional losses in different engine components. The formulation is coded in modular form whereby each module, which represents a single process in the engine, is introduced as a single block in an overall Simulink engine model. The numerical accuracy of the Simulink model is verified by comparing its results to those generated by integrating the engine formulation using IMSL stiff integration routines. The engine model is validated by the close match between the predicted and measured cylinder gas pressure and engine instantaneous speed under motoring, steady-state, and transient cold start operating conditions.

Analysis of Combustion Chamber Temperature and Heat Flux in a DOHC Engine

1997 ◽  
Author(s):  
G. H. Choi ◽  
K. H. Choi ◽  
J. T. Lee ◽  
Y.S. Song ◽  
Y. Ryu ◽  
...  
Keyword(s):  
Heat Flux ◽  
Combustion Chamber ◽  
Chamber Temperature

Effect of biodiesel fuel from soybean oil on exhaust gas and combustion chamber temperature of diesel engine

2018 ◽  
Vol 1114 ◽  
pp. 012005 ◽  
Author(s):  
Farida Ariani ◽  
Tulus B. Sitorus ◽  
Zulkifli Lubis ◽  
Tugiman ◽  
S Sriadhi
Keyword(s):  
Diesel Engine ◽  
Soybean Oil ◽  
Combustion Chamber ◽  
Biodiesel Fuel ◽  
Exhaust Gas ◽  
Chamber Temperature

An Advanced Spray Model for Application to the Prediction of Gas Turbine Combustor Flowfields

1999 ◽  
Author(s):  
Anil K. Tolpadi ◽  
Suresh K. Aggarwal ◽  
Hukam C. Mongia
Keyword(s):  
Transport Properties ◽  
Predictive Ability ◽  
Combustion Model ◽  
New Approach ◽  
Droplet Vaporization ◽  
Curve Fit ◽  
Computational Fluid Dynamics Cfd ◽  
Phase Temperature ◽  
Atomization Characteristics ◽  
Advanced Model

It is well known that fuel preparation, its method of injection into a combustor and its atomization characteristics have a significant impact on emissions. A simple dilute spray model which assumes that droplet heating and vaporization occur in sequence has been implemented in the past within computational fluid dynamics (CFD) codes at GE and has been used extensively for combustion applications. This spray model coupled with an appropriate combustion model makes reasonable predictions of the combustor pattern factor and emissions. In order to improve upon this predictive ability, a more advanced quasi-steady droplet vaporization model has been considered. This paper describes the evaluation of this advanced model. In this new approach, droplet heating and vaporization take place simultaneously (which is more realistic). In addition, the transport properties of both the liquid and vapor phases are allowed to vary as a function of pressure, gas phase temperature and droplet temperature. These transport properties which are most up to date have been compiled from various sources and appropriately curve-fit in the form of polynomials. Validation of this new approach for a single droplet was initially performed. Subsequently, calculations of the flow and temperature field were conducted and emissions (NOx, CO and UHC) were predicted for a modern single annular turbofan engine combustor using both the standard spray model and the advanced spray model. The effect of the number of droplet size ranges as well as the effect of stochastic treatment of the droplets were both investigated.

Phenomenological Modeling of Combustion in Pre-Chamber and the Pilot Flame for Natural Gas Engines

2019 ◽  
Author(s):  
Long Liu ◽  
Xia Wen ◽  
Qian Xiong ◽  
Xiuzhen Ma
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Alternative Fuels ◽  
Gas Flow ◽  
Combustion Process ◽  
Clean Energy ◽  
Combustion Model ◽  
Flame Surface ◽  
Flow Process ◽  
Natural Gas Engines

Abstract With energy shortages and increasing environmental problems, natural gas, as a clean energy, has the advantages of cheap price and large reserves and has become one of the main alternative fuels for marine diesel engines. For large bore natural gas engines, pre-chamber spark plug ignition can be used to increase engine efficiency. The engine mainly relies on the flame ejected from the pre-chamber to ignite the mixture of natural gas and air in the main combustion chamber. The ignition flame in the main combustion chamber is the main factor affecting the combustion process. Although the pre-chamber natural gas engines have been extensively studied, the characteristics of combustion in the pre-chamber and the development of ignition flame in the main combustion chamber have not been fully understood. In this study, a two-zone phenomenological combustion model of pre-chamber spark-ignition natural gas engines is established based on the exchange of mass and energy of the gas flow process in the pre-chamber and the main combustion chamber. The basic characteristics of the developed model are: a spherical flame surface is used to describe the combustion state in the pre-chamber, and according to the turbulent jet theory, the influence of turbulence on the state of the pilot flame is considered based on the Reynolds number. According to the phenomenological model, the time when the flame starts to be injected from the pre-chamber to the main combustion chamber, and the parameters such as the length of the pilot flame are analyzed. The model was verified by experimental data, and the results showed that the calculated values were in good agreement with the experimental values. It provides an effective tool for mastering the law of flame development and supporting the optimization of combustion efficiency.

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