Flame Chromatography: Toward Fuel Indexing Based on Multiple Weak Flames in a Meso-Scale Channel With a Prescribed Temperature Profile

2011 ◽  
Author(s):  
Kaoru Maruta
Keyword(s):  
Temperature Profile ◽  
Wall Temperature ◽  
Wide Temperature Range ◽  
Ignition Temperature ◽  
Flame Stability ◽  
Research Octane Number ◽  
Multi Stage ◽  
Auto Ignition ◽  
First Time ◽  
Meso Scale

For understanding flame stability in microcombustor, fundamental studies on the combustion characteristics in a meso-scale channel with a prescribed wall temperature profile have been conducted. Results showed that the existence of dynamic oscillatory flames and weak flames in addition to the normal propagating flames for the first time. It is then recognized that the weak flame phenomena can be applied for examining multi-stage oxidation of hydrocarbon fuels in wide temperature range from 300K up to auto-ignition temperature. Based on the preliminary experiments with various fuels including primary referenced fuel for gasoline, research octane number (RON) of the test fuels can be clearly described by the aspects of the stabilized stationary multiple weak flames. The methodology can be termed “flame chromatography” and it is expected to be applied for fuel indexing of future alternative fuel characterizations.

Effect of a catalytic segment on flame stability in a micro combustor with controlled wall temperature profile

Energy ◽  
2018 ◽  
Vol 165 ◽  
pp. 522-531 ◽  
Author(s):  
Shixuan Wang ◽  
Linhong Li ◽  
Yongfang Xia ◽  
Aiwu Fan ◽  
Hong Yao
Keyword(s):  
Temperature Profile ◽  
Wall Temperature ◽  
Flame Stability ◽  
Micro Combustor

scholarly journals Dynamics of premixed methane/air mixtures in a heated microchannel with different wall temperature gradients

RSC Advances ◽  
2017 ◽  
Vol 7 (4) ◽  
pp. 2066-2073 ◽  
Author(s):  
V. Ratna Kishore ◽  
S. Minaev ◽  
M. Akram ◽  
Sudarshan Kumar
Keyword(s):  
Temperature Gradient ◽  
Flame Propagation ◽  
Wall Temperature ◽  
Ignition Temperature ◽  
Temperature Gradients ◽  
Propagation Mode ◽  
Auto Ignition ◽  
Unsteady Flame

The unsteady flame propagation mode (FREI) is affected by the wall temperature gradient. As the temperature gradient approaches zero, the mixture ignites at its auto-ignition temperature, frequency decreases and this leads to extinction of FREI mode.

scholarly journals Axial Compressor Mean-Line Analysis: Choking Modelling and Fully-Coupled Integration in Engine Performance Simulations

2021 ◽  
Vol 6 (1) ◽  
pp. 4
Author(s):  
Ioannis Kolias ◽  
Alexios Alexiou ◽  
Nikolaos Aretakis ◽  
Konstantinos Mathioudakis
Keyword(s):  
Axial Compressor ◽  
Engine Performance ◽  
Engine Model ◽  
Multi Stage ◽  
Transient Simulations ◽  
Full Knowledge ◽  
Compressor Performance ◽  
First Time ◽  
Performance Calculation ◽  
Fully Coupled

A mean-line compressor performance calculation method is presented that covers the entire operating range, including the choked region of the map. It can be directly integrated into overall engine performance models, as it is developed in the same simulation environment. The code materializing the model can inherit the same interfaces, fluid models, and solvers, as the engine cycle model, allowing consistent, transparent, and robust simulations. In order to deal with convergence problems when the compressor operates close to or within the choked operation region, an approach to model choking conditions at blade row and overall compressor level is proposed. The choked portion of the compressor characteristics map is thus numerically established, allowing full knowledge and handling of inter-stage flow conditions. Such choking modelling capabilities are illustrated, for the first time in the open literature, for the case of multi-stage compressors. Integration capabilities of the 1D code within an overall engine model are demonstrated through steady state and transient simulations of a contemporary turbofan layout. Advantages offered by this approach are discussed, while comparison of using alternative approaches for representing compressor performance in overall engine models is discussed.

Pressure Sensitivity of HCCI Auto-Ignition Temperature for Oxygenated Reference Fuels

2012 ◽  
Author(s):  
Ida Truedsson ◽  
Martin Tuner ◽  
Bengt Johansson ◽  
William Cannella
Keyword(s):  
Compression Ratio ◽  
Ignition Temperature ◽  
Equivalence Ratio ◽  
Engine Speed ◽  
Pressure Sensitivity ◽  
Hcci Combustion ◽  
Air Temperatures ◽  
Auto Ignition ◽  
Temperature Heat ◽  
Pressure Trace

The current research focuses on creating an HCCI fuel index suitable for comparing different fuels for HCCI operation. One way to characterize a fuel is to use the Auto-Ignition Temperature (AIT). The AIT can be extracted from the pressure trace. Another potentially interesting parameter is the amount of Low Temperature Heat Release (LTHR) that is closely connected to the ignition properties of the fuel. The purpose of this study was to map the AIT and amount of LTHR of different oxygenated reference fuels in HCCI combustion at different cylinder pressures. Blends of n-heptane, iso-octane and ethanol were tested in a CFR engine with variable compression ratio. Five different inlet air temperatures ranging from 50°C to 150°C were used to achieve different cylinder pressures and the compression ratio was changed accordingly to keep a constant combustion phasing, CA50, of 3±1° after TDC. The experiments were carried out in lean operation with a constant equivalence ratio of 0.33 and with a constant engine speed of 600 rpm. The amount of ethanol needed to suppress LTHR from different PRFs was evaluated. The AIT and the amount of LTHR for different combinations of n-heptane, iso-octane and ethanol were charted.

scholarly journals Dissolution of iron in sodium chloride solution during alternating current polarization

2021 ◽  
Vol 318 (3) ◽  
pp. 51-62
Author(s):  
A. Bayeshova ◽  
◽  
A. Bayeshov ◽  
A. Kadirbayeva ◽  
F. Zhumabay ◽  
...  
Keyword(s):  
Sodium Chloride ◽  
Iron Hydroxide ◽  
Alternating Current ◽  
Iron Electrode ◽  
Half Cycle ◽  
Iron Compounds ◽  
Titanium Electrode ◽  
Sodium Chloride Solutions ◽  
Multi Stage ◽  
First Time

Iron compounds are widely used in many industries and engineering, and even in medicine. The existing methods of obtaining iron compounds are multi-stage and complex. The purpose of this work is to obtain iron (II) hydroxide and oxide from metal waste under alternating current action using one and two half-cycles. For the first time, the electrochemical behavior of iron electrode was studied by electrolysis method during alternating current polarization of industrial frequency in sodium chloride solutions. The iron polarization was carried out in pair with titanium, while the current density on the iron electrode varied in the range of 200-1200 A/m2, and on the titanium is in the range of 20-100 kA/m2. It is established that in the anode half-cycle of alternating current, iron is oxidized to form divalent ions. At this moment, the titanium electrode is in the cathode half-cycle, hydrogen is released on it, hydroxyl ions are formed in the cathode space. In the solution, ions interact with iron (II) ions to produce iron hydroxide. At temperatures above 600C, iron (II) hydroxide is dehydrated with the production of iron (II) oxide. The electrolysis was carried out in two electrolyzers connected to each other in parallel with the immersion of pair of “titanium-iron” electrodes into each electrolyzer. The iron dissolution occurs simultaneously in two half-cycles of alternating current and this approach is proposed for the first time. The process productivity increases by more than 1.5 times.

scholarly journals Morphology and ecology of Thalassiosira Cleve (Bacillariophyta) species rarely recorded in Brazilian coastal waters

2009 ◽  
Vol 69 (4) ◽  
pp. 1059-1071 ◽  
Author(s):  
M. Garcia ◽  
C. Odebrecht
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Water Temperature ◽  
Wide Temperature Range ◽  
Coastal Waters ◽  
Light Microscope ◽  
Temperature Range ◽  
The World ◽  
First Time ◽  
Scanning Electron

The detailed description of rarely recorded Thalassiosira species in Brazil is presented with light microscope (LM) and scanning electron microscope (SEM) illustrations. A total of 78 phytoplankton net samples (20 µm) collected between the years 2000 and 2006 in coastal waters of southern Brazilian, Cassino Beach and the estuary of Lagoa dos Patos, were studied in cleaned material using the Axiovert Zeiss LM and Jeol 6060 SEM. Water temperature and salinity of samples and six species are presented: Thalassiosira endoseriata, T. hendeyi, T. lundiana, T. minuscula, T. oceanica and T. wongii. Two species, Thalassiosira hendeyi and T. endoseriata were the most common being observed in all seasons at Cassino Beach in a wide temperature range (10-26 ºC), while only sporadically in the estuary of Lagoa dos Patos. Thalassiosira endoseriata, T. lundiana, T. oceanica and T. wongii are for the first time reported in Brazilian coastal waters. The latter two species, rarely recorded in the world, are fully illustrated based on Brazilian material.

scholarly journals A new method to derive middle atmospheric temperature profiles using a combination of Rayleigh lidar and O<sub>2</sub> airglow temperatures measurements

2012 ◽  
Vol 30 (1) ◽  
pp. 27-32 ◽  
Author(s):  
A. Taori ◽  
A. Jayaraman ◽  
K. Raghunath ◽  
V. Kamalakar
Keyword(s):  
Temperature Profile ◽  
Atmospheric Temperature ◽  
New Method ◽  
Temperature Profiles ◽  
Vertical Temperature ◽  
Lidar System ◽  
Mesospheric Temperature ◽  
Simultaneous Measurements ◽  
Rayleigh Lidar ◽  
First Time

Abstract. The vertical temperature profiles in a typical Rayleigh lidar system depends on the backscatter photon counts and the CIRA-86 model inputs. For the first time, we show that, by making simultaneous measurements of Rayleigh lidar and upper mesospheric O2 temperatures, the lidar capability can be enhanced to obtain mesospheric temperature profile up to about 95 km altitudes. The obtained results are compared with instantaneous space-borne SABER measurements for a validation.

Sign in / Sign up

Export Citation Format

Share Document