Experimental Study of Laminar Burning Speed for Premixed Biomass/Air Flame

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Ziwei Bai ◽  
Ziyu Wang ◽  
Guangying Yu ◽  
Yongping Yang ◽  
Hameed Metghalchi
Keyword(s):  
High Speed ◽  
Combustion Process ◽  
Fundamental Property ◽  
Pressure Rise ◽  
Flame Surface ◽  
Cmos Camera ◽  
One Dimensional ◽  
Co2 Concentrations ◽  
Made In ◽  
Laminar Burning Speed

Biomass has been considered as a valuable alternative fuel recently. A fundamental property of biomass/air flame, laminar burning speed, is measured in this research. Experiments have been made in a cylindrical combustion vessel with two end windows. Central ignition has been used to start the combustion process. A high-speed CMOS camera capable of taking pictures of 40,000 frames per second has been used to study morphology of flame front. Flames are initially smooth, and as pressure and flame radius increase, cracks and cells appear on the flame surface. In this paper, experimental results have only been reported for smooth flames. A multishell thermodynamic model to measure laminar burning speed of biomass/air mixture with varying CO2 concentrations (0%–60%), based on the pressure rise data collected from a cylindrical chamber during combustion, has been developed in this paper. Burning speed has been only reported for flame radii larger than 4 cm in radius in order to have negligible stretch effect. Power law correlations, to predict burning speed of biomass/air mixtures, based on the measured burning speeds, have been developed for a range of temperatures of 300–661 K, pressures of 0.5–6.9 atmospheres, equivalence ratios of 0.8–1.2, and CO2 concentrations 0%–60%. Moreover, the measured laminar burning speeds have been compared with simulation results using a one-dimensional steady-state laminar premixed flame program with GRI-Mech 3.0 mechanism and other available data from literatures. Comparison with existing data has been excellent.

Effect of Carbon Dioxide on the Laminar Burning Speed of Propane–Air Mixtures

2019 ◽  
Vol 141 (8) ◽  
Author(s):  
Sai C. Yelishala ◽  
Ziyu Wang ◽  
Hameed Metghalchi ◽  
Yiannis A. Levendis ◽  
Kumaran Kannaiyan ◽  
...  
Keyword(s):  
High Speed ◽  
Pressure Rise ◽  
Gas Temperature ◽  
Cmos Camera ◽  
Primary Input ◽  
One Dimensional ◽  
Schlieren System ◽  
Co2 Concentrations ◽  
Constant Volume Chamber ◽  
Laminar Burning Speed

This experimental research examined the effect of CO2 as a diluent on the laminar burning speed of propane–air mixtures. Combustion took place at various CO2 concentrations (0–80%), different equivalence ratios (0.7<ϕ<1.2) and over a range of temperatures (298–420 K) and pressures (0.5–6.2 atm). The experiments were performed in a cylindrical constant volume chamber with a Z-shaped Schlieren system, coupled with a high-speed CMOS camera to capture the propagation of the flames at speeds up to 4000 frames per second. The flame stability of these mixtures at different pressures, equivalence ratios, and CO2 concentrations was also studied. Only laminar, spherical, and smooth flames were considered in measuring laminar burning speed. Pressure rise data as a function of time during the flame propagation were the primary input of the multishell thermodynamic model for measuring the laminar burning speed of propane-CO2-air mixtures. The laminar burning speed of such blends was observed to decrease with the addition of CO2 and to increase with the gas temperature. It was also noted that the laminar burning speed decreases with increasing pressure. The collected experimental data were compared with simulation data obtained via a steady one-dimensional (1D) laminar premixed flame code from Cantera, using a detailed H2/CO/C1–C4 kinetics model encompassing 111 species and 784 reactions.

Measurement of Laminar Burning Speeds and Investigation of Flame Stability of Acetylene (C2H2)/Air Mixtures

2014 ◽  
Author(s):  
Emad Rokni ◽  
Ali Moghaddas ◽  
Omid Askari ◽  
Hameed Metghalchi
Keyword(s):  
Flame Propagation ◽  
High Speed ◽  
Dynamic Pressure ◽  
Combustion Process ◽  
Pressure Rise ◽  
Laminar Flames ◽  
Cmos Camera ◽  
Wide Range ◽  
Cellular Flames ◽  
Flame Structures

Laminar burning speeds and flame structures of spherically expanding flames of mixtures of acetylene (C2H2) with air have been investigated over a wide range of equivalence ratios, temperatures, and pressures. Experiments have been conducted in a constant volume cylindrical vessel with two large end windows. The vessel was installed in a shadowgraph system equipped with a high speed CMOS camera, capable of taking pictures up to 40,000 frames per second. Shadowgraphy was used to study flame structures and transition from smooth to cellular flames during flame propagation. Pressure measurements have been done using a pressure transducer during the combustion process. Laminar burning speeds were measured using a thermodynamic model employing the dynamic pressure rise during the flame propagation. Burning speeds were measured for temperature range of 300 to 590 K and pressure range of 0.5 to 3.3 atmospheres, and the range of equivalence ratios covered from 0.6 to 2. The measured values of burning speeds compared well with existing data and extended for a wider range of temperatures. Burning speed measurements have only been reported for smooth and laminar flames.

Measurement of Laminar Burning Speeds and Investigation of Flame Stability of Acetylene (C2H2)/Air Mixtures

2014 ◽  
Vol 137 (1) ◽  
Author(s):  
Emad Rokni ◽  
Ali Moghaddas ◽  
Omid Askari ◽  
Hameed Metghalchi
Keyword(s):  
Flame Propagation ◽  
High Speed ◽  
Dynamic Pressure ◽  
Combustion Process ◽  
Pressure Rise ◽  
Laminar Flames ◽  
Cmos Camera ◽  
Wide Range ◽  
Cellular Flames ◽  
Flame Structures

Laminar burning speeds and flame structures of spherically expanding flames of mixtures of acetylene (C2H2) with air have been investigated over a wide range of equivalence ratios, temperatures, and pressures. Experiments have been conducted in a constant volume cylindrical vessel with two large end windows. The vessel was installed in a shadowgraph system equipped with a high speed CMOS camera, capable of taking pictures up to 40,000 frames per second. Shadowgraphy was used to study flame structures and transition from smooth to cellular flames during flame propagation. Pressure measurements have been done using a pressure transducer during the combustion process. Laminar burning speeds were measured using a thermodynamic model employing the dynamic pressure rise during the flame propagation. Burning speeds were measured for temperature range of 300–590 K and pressure range of 0.5–3.3 atm, and the range of equivalence ratios covered from 0.6 to 2. The measured values of burning speeds compared well with existing data and extended for a wider range of temperatures. Burning speed measurements have only been reported for smooth and laminar flames.

An Analytical Approach to Understanding the “Pressure Gain” Combustor

1997 ◽  
Vol 119 (1) ◽  
pp. 49-54 ◽  
Author(s):  
M. C. Janus ◽  
G. A. Richards ◽  
R. S. Gemmen ◽  
E. K. Johnson
Keyword(s):  
Combustion Process ◽  
Stagnation Pressure ◽  
Pollutant Emissions ◽  
Primary Concern ◽  
One Dimensional ◽  
Pulse Combustor ◽  
Pressure Gain Combustion ◽  
Pulse Combustion ◽  
Commercial Applications ◽  
Made In

Although pulse combustion has been successfully utilized in various commercial applications, one potential application yet to reach the market is the pressure gain gas turbine (PGGT). A PGGT would incorporate a pulse combustor rather than the typical steady-flow combustor to increase system efficiency and decrease pollutant emissions. The distinctive advantage of pulse combustion is its ability to achieve a stagnation “pressure gain” from inlet to exit. A primary concern with pressure gain combustion development, however, is the lack of understanding as to how a combustor should be designed to achieve a pressure gain. While significant progress has been made in understanding the fundamental controlling physics of pulse combustor operation, little research has been aimed at understanding and predicting whether a given system will produce pressure gain. The following paper proposes a simple framework which helps to explain how a pulse combustor achieves a stagnation pressure gain from inlet to exit. The premise behind the framework is that pressure gain can be achieved by closely approximating a constant volume combustion process, is closely approximated by matching the resonant and operating frequencies of the system. The framework is primarily based upon results from a one-dimensional method-of-characteristics model.

Measurement of Laminar Burning Speeds and Determination of Onset of Auto-Ignition of Jet-A/Air and Jet Propellant-8/Air Mixtures in a Constant Volume Spherical Chamber

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Ali Moghaddas ◽  
Casey Bennett ◽  
Kian Eisazadeh-Far ◽  
Hameed Metghalchi
Keyword(s):  
High Pressures ◽  
Dynamic Pressure ◽  
Combustion Process ◽  
Pressure Rise ◽  
Constant Volume ◽  
Pressure Data ◽  
Spherical Vessel ◽  
Auto Ignition ◽  
Made In

The laminar burning speeds of Jet-A/air and three different samples of jet propellant (JP-8)/air mixtures have been measured and the onset of auto-ignition in JP-8/air premixed mixtures has been determined. The experiments were made in a constant volume spherical vessel, which can withstand high pressures up to 400 atm. Burning speed was calculated from dynamic pressure rise due to the combustion process in the vessel. A thermodynamic model based on the pressure rise was used to determine the burning speed. The burning speeds were measured in lean mixtures for pressures of 1–4.5 atm and temperatures of 493–700 K. The onset of auto-ignition of JP-8 fuels was evaluated by observing intense fluctuations of pressure data during the explosion of the unburned gas. It was revealed that Jet-A and JP-8 have very similar burning speeds; however, auto-ignition temperatures of various samples of JP-8 were slightly different from each other. Auto-ignition of these fuels was much more sensitive to temperature rather than pressure.

Auto-Ignition Characteristics Study of Gas-to-Liquid Fuel at High Pressures and Low Temperatures

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Omid Askari ◽  
Mimmo Elia ◽  
Matthew Ferrari ◽  
Hameed Metghalchi
Keyword(s):  
Chemical Kinetics ◽  
Low Temperatures ◽  
High Speed ◽  
High Pressures ◽  
Initial Temperature ◽  
Combustion Process ◽  
Pressure Rise ◽  
Auto Ignition ◽  
Wide Range ◽  
Gas To Liquid

Onset of auto-ignition of premixed gas-to-liquid (GTL)/air mixture has been determined at high pressures and low temperatures over a wide range of equivalence ratios. The GTL fuel used in this study was provided by Air Force Research Laboratory (AFRL), designated by Syntroleum S-8, which is derived from natural gas via the Fischer–Tropsch (F–T) process. A blend of 32% iso-octane, 25% n-decane, and 43% n-dodecane is employed as the surrogates of GTL fuel for chemical kinetics study. A spherical chamber, which can withstand high pressures up to 400 atm and can be heated up to 500 K, was used to collect pressure rise data, due to combustion, to determine the onset of auto-ignition. A gas chromatograph (GC) system working in conjunction with specialized heated lines was used to verify the filling process. A liquid supply manifold was used to allow the fuel to enter and evaporate in a temperature-controlled portion of the manifold using two cartridge heaters. An accurate high-temperature pressure transducer was used to measure the partial pressure of the vaporized fuel. Pressure rise due to combustion process was collected using a high-speed pressure sensor and was stored in a local desktop via a data acquisition system. Measurements for the onset of auto-ignition were done in the spherical chamber for different equivalence ratios of 0.8–1.2 and different initial pressures of 8.6, 10, and 12 atm at initial temperature of 450 K. Critical pressures and temperatures of GTL/air mixture at which auto-ignition takes place have been identified by detecting aggressive oscillation of pressure data during the spontaneous combustion process throughout the unburned gas mixture. To interpret the auto-ignition conditions effectively, several available chemical kinetics mechanisms were used in modeling auto-ignition of GTL/air mixtures. For low-temperature mixtures, it was shown that auto-ignition of GTL fuel is a strong function of unburned gas temperature, and propensity of auto-ignition was increased as initial temperature and pressure increased.

scholarly journals Modelling of the gas combustion process

2008 ◽  
Vol 10 (1) ◽  
pp. 15-18
Author(s):  
Teresa Baczyńska ◽  
Józef Głowiński ◽  
Adam Hałat
Keyword(s):  
Burning Velocity ◽  
Combustion Process ◽  
Pressure Rise ◽  
Maximal Rate ◽  
Gas Combustion ◽  
One Dimensional

Modelling of the gas combustion process This paper reports on a procedure which leads to the assessment of the KG values without the need of determining the maximal rate of pressure rise by experiments. A simulation is proposed of the combustion process in its simplest form, i.e. one-dimensional propagation of the flame. Such simulation enables the burning velocity Su to be assessed. Knowing the Su values for different compositions of the flammable mixture makes it possible to determine the Su, max value. Once the correlation between Su,max and KG has been established, this will enable us to assign an appropriate value of KG to that of the maximal burning velocity. An example of such a correlation is given. It refers to flammable mixtures of a comparatively low burning velocity.

Load Spectrum Compiling and Fatigue Life Estimation of the Automobile Wheel Hub

2020 ◽  
Vol 13 ◽  
Author(s):  
Xintian Liu ◽  
Yang Qu ◽  
Xiaobing Yang ◽  
Yongfeng Shen
Keyword(s):  
Fatigue Life ◽  
High Speed ◽  
Two Dimensional ◽  
Load Spectrum ◽  
One Dimensional ◽  
Life Estimation ◽  
Load Spectra ◽  
Fatigue Life Estimation ◽  
Program Load Spectrum ◽  
Program Load

Background:: In the process of high-speed driving, the wheel hub is constantly subjected to the impact load from the ground. Therefore, it is important to estimate the fatigue life of the hub in the design and production process. Objective:: This paper introduces a method to study the fatigue life of car hub based on the road load collected from test site. Methods:: Based on interval analysis, the distribution characteristics of load spectrum are analyzed. The fatigue life estimation of one - dimensional and two - dimensional load spectra is compared by compiling load spectra. Results:: According to the S-N curve cluster and the one-dimensional program load spectrum, the estimated range fatigue life of the hub is 397,100 km to 529,700 km. For unsymmetrical cyclic loading, each level means and amplitude of load were obtained through the Goodman fatigue empirical formula, and then according to S-N curve clusters in the upper and lower curves and two-dimensional program load spectrum, estimates the fatigue life of wheel hub of the interval is 329900 km to 435200 km, than one-dimensional load spectrum fatigue life was reduced by 16.9% - 17.8%. Conclusion:: This paper lays a foundation for the prediction of fatigue life and the bench test of fatigue durability of auto parts subjected to complex and variable random loads. At the same time, the research method can also be used to estimate the fatigue life of other bearing parts or high-speed moving parts and assemblies.

Vibration analysis and combustion parameter evaluation of CI engine based on Fourier Decomposition Method

2021 ◽  
pp. 146808742098819
Author(s):  
Wang Yang ◽  
Cheng Yong
Keyword(s):  
Vibration Analysis ◽  
Decomposition Method ◽  
Combustion Process ◽  
Pressure Rise ◽  
Maximum Pressure ◽  
Vibration Signals ◽  
Loop Control ◽  
Fourier Decomposition ◽  
Surface Vibration ◽  
Rise Rate

As a non-intrusive method for engine working condition detection, the engine surface vibration contains rich information about the combustion process and has great potential for the closed-loop control of engines. However, the measured engine surface vibration signals are usually induced by combustion as well as non-combustion excitations and are difficult to be utilized directly. To evaluate some combustion parameters from engine surface vibration, the tests were carried out on a single-cylinder diesel engine and a new method called Fourier Decomposition Method (FDM) was used to extract combustion induced vibration. Simulated and test results verified the ability of the FDM for engine vibration analysis. Based on the extracted vibration signals, the methods for identifying start of combustion, location of maximum pressure rise rate, and location of peak pressure were proposed. The cycle-by-cycle analysis of the results show that the parameters identified based on vibration and in-cylinder pressure have the similar trends, and it suggests that the proposed FDM-based methods can be used for extracting combustion induced vibrations and identifying the combustion parameters.

scholarly journals Detailed Injection Strategy Analysis of a Heavy-Duty Diesel Engine Running on Rape Methyl Ester

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3717
Author(s):  
Nikita Zuev ◽  
Andrey Kozlov ◽  
Alexey Terenchenko ◽  
Kirill Karpukhin ◽  
Ulugbek Azimov
Keyword(s):  
Fuel Injection ◽  
Combustion Process ◽  
Pressure Rise ◽  
Base Case ◽  
Biodiesel Fuel ◽  
Pilot Injection ◽  
Post Injection ◽  
Heavy Duty ◽  
Injection Strategy ◽  
Fuel Mass

Using biodiesel fuel in diesel engines for heavy-duty transport is important to meet the stringent emission regulations. Biodiesel is an oxygenated fuel and its physical and chemical properties are close to diesel fuel, yet there is still a need to analyze and tune the fuel injection parameters to optimize the combustion process and emissions. A four-injections strategy was used: two pilots, one main and one post injection. A highly advanced SOI decreases the NOx and the compression work but makes the combustion process less efficient. The pilot injection fuel mass influences the combustion only at injection close to the top dead center during the compression stroke. The post injection has no influence on the compression work, only on the emissions and the indicated work. An optimal injection strategy was found to be: pilot SOI 19.2 CAD BTDC, pilot injection fuel mass 25.4%; main SOI 3.7 CAD BTDC, main injection fuel mass 67.3% mg; post SOI 2 CAD ATDC, post injection fuel mass 7.3% (the injection fuel mass is given as a percentage of the total fuel mass injected). This allows the indicated work near the base case level to be maintained, the pressure rise rate to decrease by 20% and NOx emissions to decrease by 10%, but leads to a 5% increase in PM emissions.

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