Josué Melguizo-Gavilanes

• Ph.D in Mechanical Engineering
• Chargé de Recherche at French National Centre for Scientific Research

This study aims at (i) presenting detail reaction kinetics and corresponding reduced model which include nitrogen species chemistry for conditions relevant to H2-air detonations , (ii) based on the obtained kinetics, conducting the uncertainty quantification induced by the uncertainty of the rate constants on the dynamic detonation parameters (DDP)...

Two types of three-step chain-branching kinetics for gaseous hydrogen–oxygen detonation quenching are proposed. The reaction rates dependency on density and pressure, as well as the change in molecular weight are included and fitted to results of detailed chemistry not only along the Hugoniot curve but also behind transverse waves. The trend of ind...

The effect of heat and momentum losses on the steady solutions admitted by the reactive Euler equations with sink/source terms is examined for stoichiometric hydrogen–oxygen mixtures. Varying degrees of nitrogen and argon dilution are considered in order to access a wide range of effective activation energies, $$E_{\textrm{a,eff}}/R_{\textrm{u}}T_{...

An OpenFOAM® based hybrid-central solver called reactingPimpleCentralFoam is validated to compute hydrogen-based detonations. This solver is a pressure-based semi-implicit compressible flow solver based on central-upwind schemes of Kurganov and Tadmor. This solver possesses the features of standard OpenFOAM® solvers namely, rhoCentralFoam, reacting...

The capabilities of an OpenFOAM solver to reproduce the transition of stoichiometric H2-air mixtures to detonation in obstructed 2-D channels were tested. The process is challenging numerically as it involves the ignition of a flame kernel, its subsequent propagation and acceleration, interaction with obstacles, formation of shock waves ahead and d...

The number of species and elementary reactions needed for describing the oxidation of fuels increases with the size of the molecule, and in turn, the complexity of detailed mechanisms. Although the ki-netics for conventional fuels (H2 , CH4 , C3H8 ...) are somewhat well-established, chemical integration in detonation applications remains a major ch...

https://www.researchgate.net/publication/376411677_Near-limit_Detonation_in_Long_Spiral_Tube_Improved_Design_and_Methodology

A Lagrangian-based one-dimensional approach has been applied, using Cantera libraries, to study the dynamics of spherically expanding flames. Detailed reaction models have been employed to examine spherical flame propagation in hydrogen-air mixtures. In the first part, our approach was validated against laminar flame speed and Markstein number data...

Deflagration-to-detonation-transition (DDT) experiments were performed in a fully optically accessible smooth narrow channel using simultaneous schlieren visualization. Stoichiometric H2-O2 mixtures with various N2 dilution levels were used to assess the effect of dilution on flame acceleration (FA) and detonation onset (DO). Results show that the...

Modified Lotka-Volterra chemical schemes were developed with the goal of performing numerical simulation of detonation driven by single- and multi-stage heat release profiles. An initiation reaction was added to the original Lotka-Volterra model to create an induction zone, which is an important characteristics of combustion process. The kinetics p...

This experimental and numerical work reports on the dynamical behaviour of a shock in an inert gas at the concave wall of a hollow circular chamber. The gas in the chamber was air or He + \({\rm O}_{2}\) + 2 Ar at initial pressures \(p_{{\rm c0}}\) ranging from 2 to 12 kPa and initial temperature T0 =288 K. The shock was generated using a detonatio...

The influence of low temperature chemistry (LTC) on the locus of steady solutions predicted by a ZND model with curvature losses and detailed kinetics was assessed using undiluted / CO2-diluted stoichiometric DME-O2 mixtures. Results show (i) the existence of an additional critical point at large velocity deficits when the LTC sub-mechanism is incl...

The influence of ozone on quasi-steady curved detonations was numerically studied in stoichiometric H 2-air and DME-O 2 (-CO 2) mixtures with 0%, 0.1% and 1% O 3 addition. Detonation speed-curvature (D-κ) relations were determined for both fuels. The H 2-air mixture has one critical point related to high-temperature chemistry whereas the DME-O 2 (-...

The minimum detonation diameter for methane (CH4) / hydrogen (H2)-air mixtures is numerically evaluated to assess detonation risks in cooktops designed to work with natural gas. A one-dimensional mathematical model that considers heat and friction losses for detonations propagating in pipes is used for that purpose. The initial conditions are selec...

The interactions of mildly irregular detonation waves with sharp interfaces separating combustible mixtures from inert gas were modeled numerically using the Compressible Linear Eddy Model for Large Eddy Simulation (CLEM-LES) approach. In past experiments of Lieberman and Shepherd [Phys. Fluids 19, 096101 (2007)], such interactions resulted in a Tr...

This chapter provides an overview of H2 ignition and safety-related ques- tions, to be addressed in the development of future H2 thermal engines. Basics of H2 ignition phenomena are covered in the first part, including the well-known branched- chain oxidation reactions described by Semenov & Hinshelwood, as well as useful analytical derivations of...

The propagation of an isobaric premixed flame into a quiescent gas mixture of fuel and oxidizer contained between two parallel plates is investigated numerically. The plates are separated by a small distance h and considered as adiabatic. The mixture is assumed to be lean in fuel and the combustion model includes a single-step Arrhenius-type reacti...

The minimum detonation diameter for methane (CH4)/hydrogen (H2)-air mixtures is numerically evaluated to assess detonation risks in cooktops designed to work with natural gas. A one-dimensional mathematical model that considers heat and friction losses for detonations propagating in pipes is used for that purpose. The initial conditions are selecte...

A methodology to develop more predictive simplified kinetic schemes (1-step/3-step chain branching) is presented in which D-k curves obtained with detailed kinetics are used as the fitting target aiming to capture the turning point of the curve kcrit. This was motivated by the similar trend observed between the kcrit values and the critical reacti...

The problem of the steady propagation of detonation waves with friction losses is revisited including detailed kinetics. The derived formulation is used to study the influence of chemical modeling on the steady solutions and reaction zone structures obtained for stoichiometric hydrogen-oxygen. Detonation velocity-friction coefficient (D − c f) curv...

A Lagrangian-based one-dimensional approach has been developed in Cantera to study the dynamics of spherical flames. The reaction model USC-Mech II was used to examine flame propagating in hydrogen-air mixtures. In a first part, our approach has been validated against laminar flame speed and Markstein number data from the literature. In a second pa...

Shock wave refraction theory and high-resolution numerical simulations were employed to predict the refraction pattern under super-knock relevant conditions at slow-fast gas-gas interfaces which are characterized by a higher acoustic impedance in the incident phase than in the transmitted phase. First, our theoretical and computational methodologie...

A Lagrangian-based one-dimensional approach has been developed using Cantera to study the dynamics of spherically expanding flames. The detailed reaction model USC-Mech II has been employed to examine flame propagating in hydrogen-air mixtures. In the first part, our approach has been validated against laminar flame speed and Markstein number data...

Flame propagation and acceleration in unobstructed channels/tubes is usually assumed as symmetric. A fully optically accessible narrow channel that allows to perform simultaneous high-speed schlieren visualization from two mutually perpendicular directions was built to asses the validity of the aforementioned assumption. Here, we provide experiment...

The premixed propagation of lean isobaric H2-air flames (φ = 0.3) in Hele-Shaw cells (i.e. two parallel plates separated by a small distance, h, on the order of the thickness of the planar adiabatic flame, δ f ∼ 3 mm) is investigated numerically. Three-dimensional (3D) simulations with detailed chemistry and transport are used to examine the effect...

Flame propagation experiments in stoichiometric H\(_2\)–air are conducted in a smooth 482-mm-long, 10-mm \(\times \) 10-mm square-cross-section channel, closed at the ignition end and open at the opposite end. Direct observation is used to track the flame acceleration dynamics. The effect of facility specific parameters (i.e., ignition energy, boun...

Experiments are conducted in a smooth 10 × 10 mm square cross-section, 1-m long channel, closed at the ignition end and open at the other end. Simultaneous two-direction schlieren visualization is used to investigate the three-dimensional dynamics of transition to detonation for a stoichiometric H2–O2 mixture. Results show the existence of two dist...

The propagation of multidimensional gaseous detonations at elevated pressures was investigated numerically. Initial conditions at which deviations from ideal gas are expected (i.e., p0 > 2 MPa) were used to assess whether real gas effects influence their multi-cellular structure. The simplest equation of state that accounts for real gas effects was...

The external structure of the spray-flamelet can be described using the Schvab-Zel'dovich-Liñan formulation. The gaseous mixture-fraction variable as function of the physical space, Z(x i), typically employed for the description of gaseous diffusion flames leads to non-monotonicity behaviour for spray flames due to the extra fuel supplied by vapori...

The dynamics of detonation transmission from a straight channel into a curved chamber was investigated numerically and experimentally as a function of initial pressure (10 kPa ≤ p0 ≤ 26 kPa) in an argon diluted stoichiometric H2–O2 mixture. Numerical simulations considered the two-dimensional reactive Euler equations with detailed chemistry; hi-spe...

This study aims to investigate the effect of laser sheet orientation on the OH-planar laser-induced fluorescence (OH-PLIF) imaging of a detonation wave and to identify the potential benefit of using a transverse laser orientation, compared to the conventional frontal orientation. In this study, we developed a new laser-induced fluorescence (LIF) mo...

The dynamics of detonation transmission from a straight channel into a curved chamber was investigated numerically and experimentally as a function of initial pressure (10 kPa ≤ p_0 ≤ 26 kPa) in an argon diluted stoichiometric H2-O2 mixture. Numerical simulations considered the two-dimensional reactive Euler equations with detailed chemistry; hi-sp...

This study aims to investigate the effect of laser sheet orientation on the OH-PLIF imaging of a detonation wave and to identify the potential benefit of using a transverse laser orientation, compared to the conventional frontal orientation. In this study, we developed a new LIF model, based on a pre-existing one, to include a more fundamental calc...

A combined experimental and theoretical study of deflagration-to-detonation transition (DDT) in smooth narrow channels is presented. Some of the distinguishing features characterizing the late stages of DDT are shown to be qualitatively captured by a simple one-dimensional scalar equation. Inspection of the structure and stability of the traveling...

Two-dimensional simulations of detonation interaction with gravity-driven diffuse interfaces, separating reactive mixtures and inert gas, were performed using the CLEM-LES methodology. The dynamics of the interactions were characterized and detonation failure and re-initiation mechanisms were described. Triple point transmission seems to be a chara...

Experiments are conducted in a smooth 10 × 10 mm square cross-section, 1-m long channel, closed at the ignition end and open at the other end. Simultaneous two-direction schlieren visualization is used to investigate the three-dimensional dynamics of transition to detonation for a stoichiometric H 2-O 2 mixture. Results show the existence of two di...

The external structure of the spray-flamelet can be described using the Schvab- Zel’dovich-Liñan formulation. The gaseous mixture-fraction variable as function of the physical space, $Z(x_i)$, typically employed for the description of gaseous diffusion flames leads to non-monotonicity behaviour for spray flames due to the extra fuel supplied by vap...

The effect of chemistry modeling on the flow structure and quenching limits of detonations propagating into reactive layers bounded by an inert gas is investigated numerically. Three different kinetic schemes of increasing complexity are used to model a stoichiometric H 2-O 2 mixture: single-step, three-step chain-branching and detailed chemistry....

The effect of chemistry modeling on the flow structure and quenching limits of detonations propagating into reactive layers bounded by an inert gas is investigated numerically. Three different kinetic schemes of increasing complexity are used to model a stoichiometric H2-O2 mixture: single-step, three-step chain-branching and detailed chemistry. Re...

The dynamics of ignition of premixed hydrogen–air from a hot glow plug were investigated in a combined experimental and numerical study. Surface temperatures during heating and at ignition were obtained from 2-color pyrometry, gas temperatures were measured by high-speed Mach–Zehnder interferometry, and far-field effects were captured by high-speed...

The dynamics of detonation transmission from a straight channel into a curved chamber was investigated as a function of initial pressure using a combined experimental and numerical study. Hi-speed Schlieren and *OH chemiluminescense were used for flow visualization; numerical simulations considered the two-dimensional reactive Euler equations with...

Planar Laser-Induced Fluorescence of OH radical (OH-PLIF) is a common technique used to characterize the geometry of the reaction zone in weakly and highly unstable detonations. To enable direct comparison between the experimental PLIF images and 2-D numerical simulations, a LIF model is required to obtain numerical PLIF images. The goal of the pre...

Planar Laser-Induced Fluorescence of OH radical (OH-PLIF) is a common technique used to characterize the geometry of the reaction zone in weakly and highly unstable detonations. To enable direct comparison between the experimental PLIF images and 2-D numerical simulations, a LIF model is required to obtain numerical PLIF images. The goal of the pre...

A numerical study of a transiently (uniformly/non-uniformly) heated cylindrical reactor was performed using a computationally inexpensive one-step model capable of capturing the experimentally observed transition behavior from slow to fast reaction. The methodology used to find the kinetic parameters of the simplified model was described in detail....

Two-dimensional inviscid simulations are conducted to assess the effect of chemistry modeling on the detonation structure and quenching dynamics of detonations propagating into a semiconfined medium. Two different simplified kinetic schemes are used to model the chemistry of stoichiometric H 2-O 2 mixtures: single-step and three-step chain-branchin...

The ignition of hydrogen-air mixtures by a stationary hot glow plug has been experimentally investigated using two-color pyrometry and interferometry. The ignition process was characterized by the surface temperature at ignition, as well as by the location where the initial flame kernel was formed. The experimental results indicate that: (i) the ig...

A better understanding of chemical kinetics under volumetric expansion is important for a number of situations relevant to industrial safety including detonation diffraction and direct initiation, reflected shock-ignition at obstacles, ignition behind a decaying shock, among others. The ignition of stoichiometric hydrogen-air mixtures was studied u...

A combined experimental and numerical study was carried out to investigate thermal ignition by millimeter size (d=6 mm) moving hot spheres in H_2-O_2-N_2 environments over a range of equivalence ratios. The mixtures investigated were diluted with N_2 to keep their laminar flame speed constant and comparable to the sphere fall velocity (2.4 m/s) at...

A combined experimental and numerical study was carried out to investigate thermal ignition by millimeter size (d=6 mm) moving hot spheres in H2-O2-N2 environments over a range of equivalence ratios. The mixtures investigated were diluted with N2 to keep their laminar flame speed constant and comparable to the sphere fall velocity (2.4 m/s) at time...

Ignition thresholds for n-hexane-air were experimentally and numerically determined using a moving hot sphere of 6 mm in diameter. The novel experimental setup built for this purpose was described in detail. Two-color pyrometry was used for surface temperature measurements, and shearing interferometry flow field visualization was used to observe th...

Despite numerous potential industrial application of ammonia (NH3 ), the risk of detonation in NH3-based mixtures has not been characterized in details. In the present study, the velocity and cell size of detonation propagating in NH3-O2 and NH3-N2O mixtures have been measured. Mixtures containing nitrous oxide as an oxidant demonstrated higher sen...

A reduction method for detailed kinetic mechanisms is presented. The reduction procedure was performed by using the ignition delay time as the target parameter. Overall, good qualitative and quantitative comparison was observed between the reduced mechanism results and experimental parameters such as ignition delay time, laminar burning speed, and...

Steady one-dimensional numerical simulations were performed to investigate the dynamics of the ZND detonation propagating in dimethyl ether- oxygen-carbon dioxide (DME-O2-CO2) mixtures. For dilution level as low as 70%, the chemical pathways characteristic of low-temperature and intermediate-temperature hydrocarbon fuels chemistry were activated. T...

In the present study, the dynamics of stretched laminar spherical flame propagating in hydrogen-air mixtures has been investigated using Lagrangian-based one-dimensional numerical simulations. The detailed reaction model USC-Mech II has been employed. In a first part, it was shown that the laminar flame speed was predicted within 5% on average but...

Successful transition to a hydrogen economy calls for a deep understanding of the risks associated with its widespread use. Accidental ignition of hydrogen by hot surfaces is one of such risks. In the present study, we investigated the effect that rotation has on the reported ignition thresholds by numerically determining the minimum surface temper...

A better understanding of chemical kinetics under volumetric expansion is important for a number of situations relevant to industrial safety including detonation diffraction and direct initiation, reflected shock-ignition at obstacles, ignition behind a decaying shock, etc. In the present study, the ignition of stoichiometric hydrogen-air mixtures...

The methodology used to post-process a raw interferogram of a hot moving sphere falling in an inert nitrogen environment is presented. The steps taken to obtain the temperature field around the hot sphere are explained in detail. These are: (i) noise removal; (ii) phase demodulation; (iii) phase unwrapping; (iv) bias removal; and (v) Abel transform...

Experiments were carried out investigating the depressurization of a 16 mm inner-diameter polycarbonate tube partially filled with CO2 liquid expanding into a similar diameter tube. The two tubes were initially separated by a thin aluminum diaphragm. The driven tube was initially filled with nitrogen. The initial liquid CO2 level was varied (and th...

The risk of accidental ignition of flammable mixtures by a hot surface is of particular importance for industry. Accurate measurements and modeling of the minimum surface temperature for ignition to occur are needed to estimate the risk of hot surface ignition. Previous work for stationary hot surfaces have determined critical conditions for igniti...

From a scientific point of view, Deflagration to Detonation Transition (DDT) continues to draw significant interest in the research community as an outstanding, physics-rich fundamental problem in combustion science. From a practical perspective, it is important to study and understand DDT in order to develop engineering correlations and simulation...

The present study investigated hot surface ignition of C 2 H 4-air mixtures. The ignition thresholds from a stationary commercial glow plug (active heated area is 9.3 mm in height and 5.1 mm in diameter) were characterized using two-color pyrometry and high-speed interferometry. The minimum ignition temperature decreases from 1180 K to 1110 K as th...

The present article focuses on the chemical kinetics of the ignition of premixed n-hexane-air atmospheres by a moving hot sphere with emphasis on the role of low-temperature chemistry (T < 1000 K). Experiments were performed to measure the minimum surface temperature for ignition of a propagating flame and nonreactive two-dimensional simulations we...

Hot surface ignition is relevant in the context of industrial safety. In the present work, two-dimensional simulations using simplified kinetics of the buoyancy-driven flow and ignition of a slightly lean n-hexane–air mixture by a rapidly heated surface (glowplug) are reported. Experimentally, ignition is most often observed to occur at the top of...

The present article focuses on the chemical kinetics of the ignition of premixed n-hexane-air atmospheres by a moving hot sphere with emphasis on the role of low-temperature chemistry (T < 1000 K). Experiments were performed to measure the minimum surface temperature for ignition of a propagating flame and nonreactive two-dimensional simulations we...

Hot surface ignition is relevant in the context of industrial safety. In the present work, two-dimensional simulations using simplified kinetics of the buoyancy-driven flow and ignition of a slightly lean n-hexane–air mixture by a rapidly heated surface (glowplug) are reported. Experimentally, ignition is most often observed to occur at the top of...

In the present study, the ignition of hydrogen-air mixtures by a stationary hot glow plug has been investigated. The ignition process was characterized by the surface temperature when ignition occurs, as well as by the location where the initial flame kernel is formed. The experimental results indicate that the ignition temperature threshold is a f...

Studying thermal ignition mechanisms is a key step for evaluating many ignition hazards. In the present work, two-dimensional simulations with detailed chemistry are used to study the effect of differential diffusion on the prediction of ignition thresholds of a stoichiometric hydrogen-air mixture by moving hot spheres. Numerical experiments showed...

Flame propagation across a single obstacle inside a closed square channel is studied experimentally and numerically using a stoichiometric H2/O2 mixture at initial conditions 15 kPa and 300 K. The 50% blockage obstacle consists of a pair of fence-type obstacles mounted on the top and bottom walls of the channel. Direct optical visualization was per...

Studying thermal ignition mechanisms is a key step for evaluating many ignition hazards. In the present work, two-dimensional simulations with detailed chemistry are used to study the reaction pathways of the transient flow and ignition of a stoichiometric hydrogen/air mixture by moving hot spheres. For temperatures above the ignition threshold, ig...

Hot surface ignition is relevant in the context of industrial safety. In the present work, two-dimensional simulations with detailed chemistry, and study of the reaction pathways of the buoyancy-driven flow and ignition of a stoichiometric hydrogen-air mixture by a rapidly heated surface (glowplug) are reported. Experimentally, ignition is observed...

Hot surface ignition is relevant in the context of industrial safety. In the present work, two-dimensional simulations with detailed chemistry, and study of the reaction pathways of the buoyancy-driven flow and ignition of a stoichiometric hydrogen-air mixture by a rapidly heated surface (glowplug) are reported. Experimentally, in hydrocarbon-air,...

Studying thermal ignition mechanisms is a key step for evaluating many ignition hazards. In the present work, two-dimensional simulations with detailed chemistry are used to study the reaction pathways of the transient flow and ignition of a stoichiometric hydrogen-air mixture by moving hot spheres. For temperatures above the ignition threshold, ig...

Thermal ignition of flammable gaseous mixtures from a hot surface is a major concern for a wide range of industrial activities. When homogeneous hydrocarbon fuel/oxidizer mixtures are heated in a closed vessel from ambient temperature to values near their autoignition temperature these mixtures undergo either a slow reaction or an ignition, when he...

The scenario of ignition of fuels by the passage of shock waves is relevant from the perspective of safety, primarily because shock ignition potentially plays an important role in deflagration to detonation transition. Even in one dimension, simulation of ignition between a contact surface or a flame and a shock moving into combustible mixture is d...

The scenario of ignition behind a shock moving into reactive mixture is relevant from the perspective of safety (i.e. storage and handling), because it plays an important role in deflagration to detonation transition, for instance following shock reflections. Numerical simulation of ignition between a contact surface or a flame, and a shock moving...