About
74
Publications
13,538
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
1,322
Citations
Introduction
Ingmar Schoegl currently works at the Department of Mechanical Engineering, Louisiana State University. Ingmar does research in Mechanical Engineering with a focus on combustion and its applications.
Additional affiliations
August 2015 - present
August 2009 - August 2015
July 2003 - May 2009
Education
August 2003 - May 2009
October 1993 - August 2000
Publications
Publications (74)
The application of tunable diode laser absorption spectroscopy (TDLAS) to flames with nonhomogeneous temperature and concentration fields is an area where only few studies exist. Experimental work explores the performance of tomographic reconstructions of species concentration and temperature profiles from wavelength-modulated TDLAS measurements wi...
This work introduces a new focusing schlieren technique that is capable of adding color-coded directional information to the visualization of density gradients. Other advantages of the technique are that it does not require manual calibration, has a simple design and is sensitive enough to be used in compact experimental setups. While the overall m...
This study investigates the impact of pressure and dilution on combustion behavior of C2H6/air/N2 mixtures within an externally heated micro-tube using both experimental and analytical techniques. Experiments are conducted for pressures up to 10 bar at multiple dilution levels and document three flame regimes, i.e. weak flames, FREI and normal flam...
Temperature measurements based on spectral radiation are often limited by prior knowledge of target surface properties and detector sensitivity. The present work describes a multispectral pyrometry method for temperature estimation that does not require information on surface emissivity or calibration. Digital camera simulations considering a silic...
This study employs a simplified analytical model to obtain qualitative predictions of transitions between non-adiabatic combustion regimes found in non-catalytic tubular micro-flow reactors, i.e. normal stable flames, flames with repetitive extinction and ignition (FREI), and weak flames that are stabilized by wall heat transfer. Assuming large act...
The fully resolved dynamics of an elliptical particle suspended in an upward flow in an expanding channel, with successively increasing degrees of freedom of motion from a completely fixed state to an eventually fluidized state, are examined using particle resolved direct numerical simulation. The signed distance function immersed boundary method (...
Cantera is an open-source collection of object-oriented software tools for problems involving chemical kinetics, thermodynamics, and transport processes.
Small-volume, high-throughput screening techniques are sought to enable downselection from a large candidate pool of bio-blendstocks to a select few, having physical properties consistent with requirements of downsized, turbo-boosted internal combustion engines. This work presents a droplet evaporation-based approach to predict heat of vaporization...
Characteristics of non-premixed flames such as flame height and lift-off height are affected by the presence of magnetic fields due to the paramagnetic properties of some combustion species. However, it is unknown whether magnetic fields can be used to reduce the emission of pollutants in non-premixed flames.
In general, pollutant emissions are red...
Within the area of combustion, externally heated microtubes have been introduced to study the combustion characteristics of fuels and fuel blends. Microreactors have advantages over other conventional fuel testing methods because of their potential to test small volumes (< 20 μl) at high throughput. In this work, a high-pressure microreactor is des...
Micro-combustion has shown significant potential to study and characterize the combustion behavior of hydrocarbon fuels. Among several experimental approaches based on this method, the most prominent one employs an externally heated micro-channel. Three distinct combustion regimes are reported for this device namely, weak flames, flames with repeti...
Heat recirculating reactors have many potential applications as thermal oxidizers, combustors, and fuel reformers due to their extensive operating range. Low emissions and fuel flexibility make such devices highly desirable as heat sources as well as chemical reactors. The dependence on the solid/gas heat transfer implies that wall characteristics...
The formation of CO and soot is promoted in most non-premixed combustion systems due to incomplete combustion of hydrocarbon species resulting from incomplete mixing. To impede the formation of CO and soot, partial premixed configuration has been used by researchers in recent years. However, the innate characteristics of combustion species in relat...
Theoretical temperature results are commonly validated through comparisons with experimental data where a signal – for instance, the voltage caused by the presence of a temperature differential in a thermocouple – is converted into an associated temperature value. Those conversions often involve corrections, especially when the thermal field is gen...
Observation of oscillation decay in droplets has been shown to be an effective approach in determining physical properties such as viscosity and surface tension for emerging biofuels using µl quantities. This work extends the approach to higher temperatures relevant to fuel injection conditions for internal combustion engines. Experiments are condu...
Ignition delay times of a gasoline surrogate (iso-octane/toluene/n-heptane/1-hexene at 55/25/15/5% by liquid volume, developed in McCormick et al. 2017) with high-level bioblendstock-gasoline surrogate blends (50% and 85% biofuel by liquid volume of each ethanol and methyl acetate) were collected behind reflected shock waves. Post-reflected-shock t...
An ongoing effort looking at bioblendstocks to function as drop-in replacements or blending components for gasoline has identified a large number of candidate fuels. This work documents an approach for rapid screening of candidate fuels using relatively small sample sizes ($\mathcal{O}(\mu\,{\rm l})$) that targets two key physical properties of liq...
The oxidation of ethanol was investigated in shock tubes by measuring ignition delay times and water time history profiles. A laser absorption technique was used in the latter case. Ignition delay times were investigated for three equivalence ratios, 0.5, 1.0, and 2.0, and for pressures ranging from 1.3 to 53 atm. The fuel concentration and the typ...
A disk spindown experiment allows measurement of tangential momentum accommodation coefficients of different gases and material combinations in a consistent manner. Aluminum is tested for a range of gases, including monoatomic, diatomic, and triatomic gases. The results confirm previous experimental results that show a reduction in tangential momen...
To improve detailed chemical kinetics models, the oxidation of methanol was investigated behind reflected shock waves in shock tubes. Ignition delay times of methanol–air mixtures, with Ar as diluent, were studied between 940 and 1540 K in a heated shock tube, for pressures up to 14.9 atm and for equivalence ratios of 0.5, 1.0, and 2.0. Water profi...
Thin-filament pyrometry is a minimally intrusive diagnostic tool that utilizes radiance
from a thin fiber – usually with diameter of the order of microns – to estimate its temperature. The
technique is easily employed when radiation properties of the fiber, surrounding gas, and external
surfaces are known, which is not commonly the case. However, i...
Microscale combustion phenomena show fuel dependent behavior, which is of considerable interest to fuel characterization studies. In order to assess the potential of tests at elevated
pressure, combustion characteristics of ethane are studied for different levels of N2 dilution and pressure levels (1–10 bar). Experimental data are obtained for a mi...
Blends of gasoline and bio-derived blendstocks have inherent benefits for internal combustion engines, where they can improve combustion behavior while introducing renewable fuel
sources. In order to assess combustion characteristics, a rapid means of fuel characterization is
desirable, where micro flow reactors have considerable potential in low-v...
The thermal decomposition of ethanol has been studied under pyrolytic conditions behind reflected shock waves in the 1250 to 1677 K temperature range, at an average pressure of 1.31 atm for a mixture highly diluted in Ar. A laser absorption technique was utilized to measure H2O time-histories, and the detailed kinetics mechanism (AramcoMech2.0) was...
Temperature measurements based on spectral radiation emitted from a target surface are often limited
by prior knowledge of the emissivity of the surface. As an alternative, multi-wavelength pyrometry
approaches, in which thermal radiation is evaluated at two or more wavelengths, allow both emissivity
and temperature of the target surface to be esti...
In this study, combustion characteristics of Primary Reference Fuels (PRFs: n-heptane/iso-octane mixtures) are investigated at atmospheric and moderate pressure in a microchannel exposed to a controlled temperature profile produced by a flat flame burner. Tests with stoichiometric PRF/air mixtures are carried out with inlet velocities ranging from5...
Most flow visualizations and flow measurements to understand particle mobility in porous media are typically performed in transparent microfluidic devices (micro-models) with 2D pore-throat networks. Nano-particle mobility studies to date have been limited to micro-models made of transparent thermoplastic or silicone-based materials. In an effort t...
A ceramic-based micromodel was fabricated with batching of green alumina ceramics mixed with polymer binders, extrusion of the green alumina tapes, and hot embossing of the green tapes with a metal mold. The metal mold fabricated using optical lithography of SU8 and electroforming of nickel contained 2.5D pore network geometry in 13 layers of a roc...
Premixed flames propagating within small channels show complex combustion phenomena that differ from flame propagation at conventional scales. Available experimental and numerical studies have documented stationary, non-stationary, or asymmetric modes that depend on properties of the incoming reactant flow as well as channel geometry and wall tempe...
Glycerol is available in high volumes and at low costs as a byproduct of bio-diesel production. While combustion characteristics are poor, it is appealing to investigate potential reforming processes to recover its hydrogen and carbon in the form of synthesis gas, i.e. a combustible mixture of hydrogen, carbon monoxide, methane and other small hydr...
The auto-ignition and extinction behavior of gaseous fuels is investigated experimentally for flames with repetitive extinction and ignition (FREI) in a millimeter-scale quartz tube. The experimental approach has the potential to evaluate key fuel properties from very small samples by establishing a link between chemical kinetics and FREI dynamics....
Chemical Explosive Mode Analysis (CEMA) is used to illustrate how source terms and reactions associated with state variables drive the combustion process across a large database of lean, premixed H2/air flames with detailed chemistry. Based on an eigenanalysis of chemical sources terms, chemical source modes and associated reaction modes are distin...
Premixed flames propagating within small channels show complex combustion
phenomena that differ from flame propagation at conventional scales. Available
experimental and numerical studies have documented stationary/non-stationary
and/or asymmetric modes that depend on properties of the incoming reactant flow
as well as channel geometry and wall tem...
The objective of this study is to investigate the choice of thermoplastic binders in a two-step debinding process involving solvent extraction (SE) and thermal debinding (TD) of samples produced using polymer (co-)extrusion. Two-step debinding uses a binder system combining soluble binders and thermoplastic binders, which are removed by SE and TD,...
In reduced-order modeling of premixed combustion, a major concern is whether chemistry submodels capture flame characteristics over a broad range of mixture stoichiometries and reactant temperatures. In order to adapt to local temperature level and stoichiometry, models require a suitable parameterization. Post-processing of a large database of adi...
The objective of this study is to assess the feasibility of solvent extraction (SE) for partial binder removal in the context of polymer co-extrusion with a thermoplastic binder component. Polymer co-extrusion is able to produce multilayered, functionally graded and/or textured structures in an efficient manufacturing process, but requires a polyme...
Temperature and concentration distributions of a horizontal section through a simulated stationary test flame were reconstructed with the help of computer tomography. The study uses temperature and concentration distributions equal to published time-averaged data for the Sandia D flame. Projection values are obtained by simulated line-of-sight inte...
Laminar, premixed flames show different dynamics in small scale channels than in large scale systems. Flame behavior is found to be sensitive to the operating conditions, including inlet velocity, channel height and fuel mixture composition. In previous simulations, a range of flame dynamics was reported in small 2-D channels with detail chemistry...
Due to high efficiency and low emission levels, lean premixed flames are of considerable interest in combustion research. This work seeks to identify progressions of characteristics that are common to premixed flames with varying stoichiometry and inlet temperature, where both non-adiabatic and diluted cases are considered. Databases for large numb...
Over the past decade, a series of studies has demonstrated non-catalytic hydrogen production via partial oxidation of fuel-rich mixtures that lie well beyond the conventional rich flammability limits. In all cases, heat recirculation from the post-reaction zone to the unburned mixture leads to significant increases of combustion temperatures and ma...
Combustion-based personal power systems have great potential for applications that demand high energy density, compact, and durable components. Through the use of heat recirculation, increased combustor firing rates and extension of flammability limits can be achieved. This study examines the combustion of lean methane/air reactant mixtures below t...
Abstract In this work, millimeter-scale tubular combustion channels were fabricated from ceramic precursor materials. Co-extrusion of structured feedrods holds promise for the development of multi-layered, functionally graded and/or textured combustor walls, but requires a polymer binder that is difficult to remove before structures can be sintered...
The study compares the performance of different pathways for gas-phase (non-catalytic) fuel reforming between 600 and 1000 °C. Specifically, the conversion of propane to hydrogen-rich syngas was investigated numerically and experimentally for pyrolysis (Py), steam reforming (SR), partial oxidation (POx), and autothermal reforming (ATR). Experiments...
Lean premixed laminar combustion in narrow channels is known to display a range of different flame behaviors: periodic ignition/extinction, symmetric flat/V-shaped, asymmetric, oscillating between two asymmetric flames and axially pulsating asymmetric flames. The specific combustion mode depends on the operating conditions, where inlet velocity, eq...
FULL TEXT : http://www.che.utah.edu/~sutherland/USCI2013/PAPERS/3C09-070DI-0380.pdf
Tomographic techniques allow for the reconstruction of spatially varying temperature and concentration fields in a flame from line-of-sight integrated tunable diode laser absorption spectroscopy (TDLAS) measurements. Such methods generally need data taken from a la...
Key features of the flame structure remain unchanged throughout the lean and ultra-lean premixed regime, where peak temperatures are a natural parameter. As estimates for peak temperatures can be calculated from local states and transport processes, future expansions to arbitrary reacting flows are envisioned.
The ultra-lean combustion regime extends below the conventional lean flammability limit, where viable flames require substantial preheating of the reactant mixture. A large number of simulations of adiabatic laminar flames with detailed reaction kinetics and pseudo-randomly distributed inlet temperatures (Tin=300-1000K) and equivalence ratios (phi=...
Abstract Temperature and concentration distributions of a simulated flame were reconstructed with the help of computer tomography and tunable diode laser absorption spectroscopy (TDLAS). Reconstructions were based on the simulated numerical values of temperature and concentration of a stationary flame. Integrated absorption measurements along the l...
This study investigates the impact of radiative heat transfer on the behavior of flat flame burners within the framework of a simplified one-dimensional model. Flat flame burners stabilize planar premixed flames downstream of a porous plug. Within this study, the porous plug is modeled as a thermally conducting, optically thick medium, allowing for...
Temperate and concentration distributions of a horizontal section through a stationary test flame were reconstructed with the help of computer tomography. Simulated reconstructions are based on temperature and concentrations distributions equal to published time-averaged data of the Sandia D flame. Based on property distributions, line integrated a...
Abstract Temperature and concentration distributions of two standard flames were reconstructed with the help of computer tomography. Reconstructions were based on time-averaged temperature and species data of the axially symmetric Sandia D flame and steady state data for a McKenna flame assuming stoichiometric methane-air composition. Line integrat...
A study of preheated methane-air flat flames at ultra-lean conditions is performed numerically. Computations were performed utilizing adiabatic flame and burner stabilized flame codes in the Cantera software package as well as the GRI 3.0 mechanism for kinetics. Within the flame structure, chemical kinetic indicators are sought to tie flame positio...
This paper investigates the hydrodynamic behavior of a small, laboratory scale, conical spouted bed (CSB) by considering the effect of specific system parameters (stagnated bed height, particle size and inlet diameter) on minimum spouting velocity (u ms ) o , stable operating pressure drop (∆P ms ) and maximum pressure drop (∆P M ). Experimental re...
Recirculation of heat has been used for decades to react mixtures beyond the conventional flammability limits. One means of obtaining this recirculation is through counter-flow heat exchange. In contrast to filtration combustion in which a reaction front propagates through a packed bed, counter-flow heat exchange results in stationary reactions zon...
Current advances in mobile devices bring about power demands that are quickly outpacing available battery technologies. Portable power systems based on fuel cells promise higher power densities, but face challenges with respect to the storage of suitable fuels. Hydrocarbon fuels offer high power densities and can be reformed into a hydrogen-rich sy...
Although hydrogen is abundant in nature, it is primarily bound into other molecules such as hydrocarbons. The conversion, or reforming, of a hydrocarbon into a hydrogen-rich syngas may be accomplished through either catalytic or non-catalytic processes. In this paper, we examine a non-catalytic reactor for syngas production that consists of multipl...
The conversion of liquid heptane to syngas in a porous medium reactor consisting of a packed bed of alumina pellets is investigated numerically and experimentally. In experiments, the exhaust gas was analyzed for hydrogen, carbon monoxide, carbon dioxide, methane, and hydrocarbon species over equivalence ratios from 1.4 to 3.8 and a range of mixtur...
Classic theories of combustion rely upon the principle that the maximum temperature attainable in a reaction is predicted by the adiabatic equilibrium temperature. In certain burner configurations, however, the maximum temperature may locally exceed this value by a significant amount due to heat recirculation, which has led to the concept of supera...
Classic theories of combustion rely upon the principle that the maximum temperature attainable in a reaction is predicted by the adiabatic equilibrium temperature. In certain burner configurations, however, the maximum temperature may locally exceed this value by a significant amount due to heat recirculation, which has led to the concept of supera...