In the case of spherically symmetric chemical burning, only very special hydrodynamical detonation solutions exist. These are the so called Jouguet detonations, in which the burning front moves at sound velocity with respect to the burnt matter. Usually it is believed that the situation is similar in the case of bubble growth in cosmological phase transitions. In this paper it is shown that act...

Laminar burning velocity is strongly dependent on mixture characteristics, e.g. initial temperature, pressure and equivalence ratio. In this work, spherically expanding laminar premixed flames, freely propagating from a spark ignition source in initially quiescent ethanol-air mixtures, have been imaged and then the laminar burning velocities were obtained at initial temperatures of 358 K to 500...

The trappingandtransport of sootaggregatesbetween a burningsuspendeddroplet and its  ame in a convectionfree (microgravity) environment are discussed. Many researchers have utilized the suspended droplet method for studyingdroplet combustion in microgravitywhere the intent is to create a spherically symmetric burning process. In the ideal case, soot particles are trapped in a spherical shell-l...

Laminar burning velocities and flammability limits of premixed methane/air flames in the presence of various inert gases including helium, argon, nitrogen and carbon dioxide were investigated by combined use of microgravity experiments and computations. The experiments used a short-drop free-fall laboratory facility that can eliminate the effect of buoyancy on flames and therefore enable accura...

Using the proton transfer reaction mass spectrometry (PTR-MS) technique, acetonitrile was measured during the wet season in a Venezuelan woodland savanna. The site was located downwind of the Caribbean Sea and no biomass burning events were observed in the region. High boundary layer concentrations of 211±36 pmol/mol (median, ±standard deviation) were observed during daytime in the well mixed b...

Wind is one of the main forces affecting the rate of forest fire spread. It may either increase or decrease the energy transferred toward the unburned areas. The present study is devoted to understanding the effect of wind on the propagation of forest fires. To model the propagation of forest fires a semiphysical approach is used. By this approach forest fire is considered as an adiabatic combu...

In this paper, a new guidance method for surface to surface ballistic missiles without mandatory engine cut-off will be presented. The complexity of solid fuel engine cut-off demands a comprehensive method for guiding these missiles. In the method presented in this paper, a certain guidance law is applied such that by transmitting appropriate commands to the control system, by changing the miss...

A new model for turbulent flame velocity of premixed flame in spark ignition engine for Iso-octane air mixture has been developed and validated for a wide range of engine operating parameters. The model developed is a zero dimensional thermodynamic model. The effects of engine speed (600-1160 rpm), equivalence ratio (0.7-1.1), unburnt mixture temperature (532650 Rankine), compression ratio (5-8...