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.

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 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.

Mass Burning Rate of Syngas/Air Mixtures and Gas to Liquid Fuel Auto-Ignition at High Temperatures and Pressures

2016 ◽  
Author(s):  
Mimmo Elia ◽  
Matthew Ferrari ◽  
Omid Askari ◽  
Hameed Metghalchi
Keyword(s):  
Burning Rate ◽  
High Temperatures ◽  
High Speed ◽  
Equivalence Ratio ◽  
Initial Pressure ◽  
Mass Burning Rate ◽  
System Effect ◽  
Auto Ignition ◽  
Wide Range ◽  
Gas To Liquid

Mass burning speed and onset of auto-ignition of premixed syngas/air and gas to liquid (GTL)/air mixtures respectively, have been determined at high temperatures and pressures over a wide range of fuel-air equivalence ratios. The experimental facilities consist of two spherical and cylindrical vessels. The spherical vessel was used to collect pressure data to measure the burning speed, mass burning rate and determine the onset of auto-ignition and cylindrical vessel was used to take pictures of flame propagation with a high speed CMOS camera up to 40,000 frame per second located in a Schlieren system. Effect of cellular flames on mass burning rate have been determined. Critical pressures and temperature for different fuel air equivalence ratios at which auto-ignition takes place have been measured. In this paper, mass burning rate of syngas is calculated for a wide range of equivalence ratio from 0.6 to 2, unburned temperature from 400 to 680 K and initial pressure from 2 to 25 atm. A power law correlation has been developed as a function of equivalence ratio, temperature and pressure. The onset of auto-ignition for GTL/air mixture has been identified for equivalence ratio of 0.8 to 1.2.

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.

scholarly journals Experimental investigation of a gel fuel combustion process initiated by a hot particle

2018 ◽  
Vol 209 ◽  
pp. 00025
Author(s):  
Aleksandr Nigay ◽  
Dmitriy Glushkov
Keyword(s):  
High Speed ◽  
Initial Temperature ◽  
Combustion Process ◽  
Experimental Studies ◽  
Chemical Processes ◽  
Metal Particles ◽  
Experimental Setup ◽  
Ignition Delay Times ◽  
Delay Times ◽  
Physical And Chemical

Experimental studies were performed for crude oil-based fuel samples. The initial temperature of the samples varied down to 120 K. Ignition was performed by single metal particles of various shapes and temperatures, which reached 1350 K. A specially developed experimental setup allowed recording of the proceeding processes at a high speed. As a result, the characteristics of physical and chemical processes were analysed. Conditions necessary for stable ignition and ignition delay times were determined depending on various conditions.

scholarly journals Mechanical Properties of Brass under Impact and Perforation Tests for a Wide Range of Temperatures: Experimental and Numerical Approach

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5821
Author(s):  
Maciej Klosak ◽  
Tomasz Jankowiak ◽  
Alexis Rusinek ◽  
Amine Bendarma ◽  
Piotr W. Sielicki ◽  
...  
Keyword(s):  
High Speed ◽  
Failure Modes ◽  
Initial Temperature ◽  
Numerical Study ◽  
Numerical Approach ◽  
Velocity Versus ◽  
Rectangular Plates ◽  
Brass Alloy ◽  
Damage Initiation ◽  
Wide Range

The originally performed perforation experiments were extended by compression and tensile dynamic tests reported in this work in order to fully characterize the material tested. Then a numerical model was presented to carry out numerical simulations. The tested material was the common brass alloy. The aim of this numerical study was to observe the behavior of the sample material and to define failure modes under dynamic conditions of impact loading in comparison with the experimental findings. The specimens were rectangular plates perforated within a large range of initial impact velocities V0 from 40 to 120 m/s and in different initial temperatures T0. The temperature range for experiments was T0 = 293 K to 533 K, whereas the numerical analysis covered a wider range of temperatures reaching 923 K. The thermoelasto-viscoplastic behavior of brass alloy was described using the Johnson–Cook constitutive relation. The ductile damage initiation criterion was used with plastic equivalent strain. Both experimental and numerical studies allowed to conclude that the ballistic properties of the structure and the ballistic strength of the sheet plates change with the initial temperature. The results in terms of the ballistic curve VR (residual velocity) versus V0 (initial velocity) showed the temperature effect on the residual kinetic energy and thus on the energy absorbed by the plate. Concerning the failure pattern, the number of petals N was varied depending on the initial impact velocity V0 and initial temperature T0. Preliminary results with regard to temperature increase were recorded. They were obtained using an infrared high-speed camera and were subsequently compared with numerical results.

Combustion in High-Speed Direct Injection Diesel Engines—A Comprehensive Study

1994 ◽  
Vol 208 (4) ◽  
pp. 223-240 ◽  
Author(s):  
D E Winterbone ◽  
D A Yates ◽  
E Clough ◽  
K K Rao ◽  
P Gomes ◽  
...  
Keyword(s):  
High Speed ◽  
Direct Injection ◽  
Combustion Process ◽  
Operating Conditions ◽  
Correlation Technique ◽  
Full Field ◽  
Combustion Gases ◽  
Carbon Particles ◽  
Wide Range ◽  
Cross Correlation Technique

This paper reports the latest results of a comprehensive project investigating the performance of a Ricardo Hydra direct injection diesel engine. Early work covered a number of aspects of research into the gross behaviour of this engine: this paper concentrates on techniques for obtaining quantitative data from photographs of the combustion process. High-speed photographs, at framing rates up to 20 000 frames/s, were taken using a piston with a quartz bowl, at engine speeds up to 3000 r/min. The pre-combustion period was illuminated using a synchronized copper vapour laser. After the initiation of combustion, the process is self-illuminating and information on the combustion process was obtained by analysing the radiation emitted by the carbon particles. The two-colour method was used to evaluate the temperature of the combustion gases over the full field of view. The images have also been analysed by a cross-correlation technique to obtain velocity information. Tests have been performed on the engine over a wide range of operating conditions, but this paper concentrates on the effect of swirl ratio on combustion. It will be shown that too much swirl increases the ignition delay period and results in an increase in the NOx emissions but a decrease in the soot. It will also be shown that the velocity pattern after combustion is in good agreement with that evaluated by Arcoumanis et al. at the end of compression, which implies that swirl persists through the combustion period despite significant decay.

Analysis of Aluminum and Steel Pistons: Comparison of Friction, Piston Temperature, and Combustion

2013 ◽  
Author(s):  
Kai Schreer ◽  
Ingo Roth ◽  
Simon Schneider ◽  
Holger Ehnis
Keyword(s):  
Fuel Consumption ◽  
Diesel Engines ◽  
High Speed ◽  
Process Analysis ◽  
Combustion Process ◽  
Cylinder Liner ◽  
Thermodynamic Efficiency ◽  
Series Production ◽  
Steel Piston ◽  
Wide Range

While steel pistons have been in use for a long time in commercial vehicle diesel engines, the first series production applications for passenger car diesel engines are currently imminent. The main reason for the use of steel pistons in high speed diesel engines is not, as maybe initially hypothesized, the increasing requirements on the component strength due to increasing mechanical loads, but rather challenges based on the actual CO2-legislation. The increasing requirements to reduce the fuel consumption necessitate new innovative technologies. The imminent penalties for exceeding the prescribed CO2 emissions seem to make the steel piston a viable alternative today, despite its higher manufacturing costs. So far, the CO2-benefits using steel pistons were mainly ascribed to the reduced friction between piston and cylinder liner due to no thermal interference. Fuel consumption measurements at vehicle manufacturer and research institutes hypothesize also an influence of the steel piston on the thermodynamic efficiency. MAHLE uses engine tests to investigate one piston variant made of aluminum (series production piston with cooled ring carrier) and one of steel (MAHLE TopWeld) in a detailed system comparison. Using a fully indicated engine, a combustion process analysis is performed and used as the basis for a loss analysis. The engine set-up parameters can be adjusted fully variable using a flexible ECU. The effect that the piston variant has on the combustion process is captured and balanced, e.g., by adjusting the parameters to obtain identical emissions. The analysis records the potential of the variants for each engine operating map area. The thermal conditions for the piston and the piston wall temperature on the combustion chamber side are varied over a wide range using a conditioning device for piston cooling. The influence of this intervention on the thermal load of the piston and the combustion and also the influence of different combustion mappings is measured directly by telemetric piston temperature measurement. MAHLE recently completed a system comparison [3] between aluminum and steel pistons with detailed measurements on a fully indicated engine, covering friction and temperature behavior as well as influences on combustion.

Burning Speed Measurement of JP-8 Air Flames

2004 ◽  
Author(s):  
Farzan Parsinejad ◽  
Christian Arcari ◽  
Edwin Shirk ◽  
Hameed Metghalchi
Keyword(s):  
High Speed ◽  
Variable Temperature ◽  
Dynamic Pressure ◽  
Flame Structure ◽  
Pressure Rise ◽  
Ccd Camera ◽  
Cylindrical Vessel ◽  
Spherical Vessel ◽  
Speed Measurement ◽  
Wide Range

Burning speed measurement and structure of JP-8 air mixtures at a wide range of temperature and pressure have been studied using two matched constant volume chambers. The experimental facilities include a spherical chamber and cylindrical vessel with glasses at the end caps to enable us visualizing flame structure. Cylindrical vessel is located in a Schlieren set up including spherical mirrors and a high speed CCD camera. Facilities also include and oven which can raise the initial temperature of the mixtures in spherical vessel to 500 K and similar heating elements that perform the same task in cylindrical chamber. A thermodynamic model has been developed to calculate burning speeds using dynamic pressure rise in the chamber. The model considers a central burned gas core of variable temperature surrounded by an unburned gas shell with uniform temperature with a thermal boundary layer at the wall. Burning speed and flame structure of different gaseous fuel-air mixtures have been investigated. Autoignition characteristics of JP-8 air mixtures have also been determined by the sudden pressure rise in spherical vessel.

Use of Detailed Chemical Kinetics to Study HCCI Engine Combustion With Consideration of Turbulent Mixing Effects

2002 ◽  
Vol 124 (3) ◽  
pp. 702-707 ◽  
Author(s):  
S.-C. Kong ◽  
R. D. Reitz
Keyword(s):  
Chemical Kinetics ◽  
Turbulent Mixing ◽  
Combustion Process ◽  
Reaction Rates ◽  
Detailed Chemical Kinetics ◽  
Wide Range ◽  
Hcci Engines ◽  
Heavy Duty Diesel ◽  
Flame Chemistry ◽  
Detailed Chemical

Detailed chemical kinetics was used in an engine CFD code to study the combustion process in HCCI engines. The CHEMKIN code was implemented in KIVA such that the chemistry and flow solutions were coupled. The reaction mechanism consists of hundreds of reactions and species and is derived from fundamental flame chemistry. Effects of turbulent mixing on the reaction rates were also considered. The results show that the present KIVA/CHEMKIN model is able to simulate the ignition and combustion process in three different HCCI engines including a CFR engine and two modified heavy-duty diesel engines. Ignition timings were predicted correctly over a wide range of engine conditions without the need to adjust any kinetic constants. However, it was found that the use of chemical kinetics alone was not sufficient to accurately simulate the overall combustion rate. The effects of turbulent mixing on the reaction rates need to be considered to correctly simulate the combustion and heat release rates.

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