RANKING OF FUEL-AIR MIXTURES IN TERMS OF THEIR PROPENSITYTO DEFLAGRATION-TO-DETONATION TRANSITION

The term "detonability" with respect to fuel-air mixtures (FAMs) implies the ability of a reactive mixture of a given composition to support the propagation of a stationary detonation wave in various thermodynamic and gasdynamic conditions. The detonability of FAMs, on the one hand, determines their explosion hazards during storage, transportation, and use in various sectors of the economy and, on the other hand, the possibility of their practical application in advanced energy-converting devices operating on detonative pressure gain combustion.

NUMERICAL STUDY OF DETONATION PROPAGATION IN VISCOUS TURBULENT FLOW IN A DUCT

Gasdynamics of detonation waves was widely studied within last hundred years - analytically, experimentally, and numerically. The majority of classical studies of the XX century were concentrated on inviscid aspects of detonation structure and propagation. There was a widespread opinion that detonation is such a fast phenomenon that viscous e¨ects should have insigni¦cant in§uence on its propagation. When the era of calculations based on the Reynolds-averaged Navier- Stokes (RANS) and large eddy simulation approaches came into effect, researchers pounced on practical problems with complex geometry and with the interaction of many physical effects. There is only a limited number of works studying the in§uence of viscosity on detonation propagation in supersonic §ows in ducts (i. e., in the presence of boundary layers).

MULTIDIMENSIONAL SIMULATIONS AND TEST FIRES OF A HYDROGEN-FUELED RAMJET WITH AN ANNULAR DETONATIVE COMBUSTOR AT APPROACHING AIR FLOW OF MACH 2 AND 1.5

Modern high-speed unmanned aerial vehicles are powered with small-size turbojets or ramjets. Existing ramjets operating on the thermodynamic cycle with de§agrative combustion of fuel at constant pressure are efficient at flight Mach numbers M ranging from about 2 to 6.

PROPAGATION OF THE BURNING WAVE IN A PULSED DETONATION COMBUSTOR OPERATING ON MIXTURES OF HEPTANE AND JET A-1 WITH AIR AND OXYGEN AT [O2/AIR] < 1

This work is devoted to the study of the dynamics of combustion wave propagation in oxygen-enriched mixtures of n-heptane with air and jet fuel "Jet A-1" in a small-size pulsed detonation combustor (PDC) with a diameter of 20 mm and a length less than 1 m. Experiments are carried out after the PDC reaches a stationary thermal regime when changing the equivalence ratio (ϕ = 0.73-1.89) and the oxygen-to-air ratio ([O2/air] = 0.15-0.60). The velocity of the combustion wave is determined by measuring the propagation time of the flame front between adjacent pressure sensors that form measurement segements along the PDC.

HIGH-RESPONSE COMPLEX FOR ANALYZING DROPLETS AND VAPORS IN AEROSOL CLOUDS FORMED IN THE ATMOSPHEREDUE TO LIQUID DISPERSION

The high-response diagnostic complex for remote control and analyses of droplets and vapors of mazut, oil, gasoline, kerosene, diesel fuel and liquefied natural gas in the clouds and turbulent aerosolflows in the atmosphere with volume up to 107 m3 is described.

NUMERICAL SIMULATION OF THE COMPACTION EFFECT DURING SHOCK WAVE € PARTICLE LAYER NUMERICAL SIMULATION OF THE COMPACTION EFFECT DURING SHOCK WAVE-PARTICLE LAYER INTERACTION

The problem of shock wave - dense particle layer interaction is a fundamental basis for the study of a more complex process of dust explosion or dust-layered detonation. The work presents results of numerical simulation of the experiment on interaction of an SW with particles layer deposited on the impermeable wall.

DETONATION PROPAGATIONIN PERIODIC NONUNIFORM MEDIA: RESONANCE AND MODE LOCKING PHENOMENA

In recent work [1], the analog Burgers model of detonation [2] was used in order to explore how detonation propagates in a medium with periodically varying reactivity.

FEATURES OF AUTOIGNITION OF METHANE-HYDROGEN MIXTURES

The results of experimental studies and the kinetic simulation of au- toignition of stoichiometric methane-hydrogen-air mixtures in the temperature range of 700-1000 K and pressures of 1-15 atm, relevant to the possibility of undesired autoignition (knock) in a spark-ignition engine are presented.

FAST COMBUSTION MODES OF COMPOSITES "MOUND OF POROUS SILICON FRAGMENTS-SODIUM PERCHLORATE MONOHYDRATE" IN THE ATMOSPHERE

Numerous studies have demonstrated the potential use of porous silicon (pSi) as an energetic material. However, there are a number of dificulties in such an application of nanostructured silicon. Here are two of the most serious dificulties.

FEATURES OF P-TYPE SILICON COMBUSTION IN THE SOLID FUEL PSI-NACLO4 · H2O COMPOSITES

The ability of porous silicon to actively participate in oxidative reactions leading to combustion and explosion when interacting with reagents in the pores was established about twenty years ago [1] but because of the high propagation velocities of these physicochemical transformations (102-103 m/s), it was di©cult to understand their mechanisms.