Antoine Osmont

Thermodynamic data for the modeling of the thermal decomposition of biodiesel. 1. Saturated and monounsaturated FAMEs.

Thermochemical data were computed for numerous species needed for performing detailed chemical kinetic modeling of biodiesel thermal decomposition and combustion. Most of these data concerning large species had not been experimentally determined. A B3LYP/6-31G(d,p) method using the atomization approach derived earlier was used to provide these data. The presently computed thermochemical data are provided in the CHEMKIN-NASA format as Supporting Information. Species considered are fatty acid methyl esters (FAMEs), various oxygenated radicals formed from FAMEs by C-H, C-C, and C-O bond breakings and subsequent chemistries, 1-, 2-, 3-, and 5-saturated alkyl radicals, monounsaturated 1-alkyl radicals, among others.

Incident pressure measurement in air blast using wireless sensors

This paper presents the wireless measurement of the incident pressure inside the fire ball of an air blast shock wave. The wireless sensor set-up and the experimental configuration are described. The wired and wireless experimental results are compared and analyzed. To our best knowledge, it is the first time that a wireless device takes place inside the fireball of an explosion for the measurement of the incident pressure in such harsh environment.

Reflection of Electromagnetic Waves From Moving Interfaces for Analyzing Shock Phenomenon in Solids

A new closed-form expression is derived in this paper for computing the electromagnetic field reflected by two moving interfaces. The interfaces velocities and refractive index between interfaces are then derived from measurable frequencies and amplitudes embedded in the reflected electromagnetic field. As an application, the remote analysis of the shock wave phenomenon in solids is reported and shock wave descriptors are estimated. Based on the proposed approach, physical insights on published measurement results are reported. Two cases are investigated: one from the literature and one from new data on shock loading of PolyMethyl MethAcrylate.

Determination of the JWL Coefficients of the Hexomax Explosive

The replacement of plastrite by Hexomax leads to determinate and validate the equation of state parameters of the detonation products, in the goal to make performances numerical calculations of this energetic material. The Chapman- Jouguet state is calculated using two ways, firstly from simulations with the thermo-chemical code named SIAME developed by the CEA for the French DGA and conventional defense applications, secondly from an approach based on empirical relations available in the literature. The hypothesis of a mean value for the polytropic coefficient in the ambient state of detonation products and also for exponential decreasing members coefficients of JWL equation allows to reach to other parameters according the strength to respect the detonation CJ state. Inside SIAME, these coefficients are obtained by minimization of the JWL equation isentropic form of the detonation products CJ expansion. Used in a hydrodynamical calculation code (OURANOS, LS-DYNA), JWL parameters allow to compare the numerical simulation results to experimental results of the cylinder test. The correlation is very good with parameters from the thermo-chemical simulation. The empirical method looks like a FREM (« Fast Running Engineer Model ») leading to a good approximative solution of JWL parameters when the necessary enthalpy of formation for the thermo-chemical simulation is not available. The JWL parameters are used afterwards to evaluate the Hexomax blast effects for aerial detonation.