Lipika Kabiraj, R. I. Sujith, Pankaj Wahi † ‡ Department of Aerospace Engineering Indian Institute of Technology Madras Chennai 600036, India [email protected], [email protected] Department of Mechanical Engineering Indian Institute of Technology Kanpur Kanpur-208016, India [email protected] ABSTRACT Spontaneous pressure and heat release rate oscillations can get excited in a confined combu...

Large eddy simulation (LES) is a promising method for numerical simulation in combustion systems. A LES attempt in a model combustor has been made, and a few important issues related to grid size, inflow condition, wall boundary conditions, physical sub-models and data sampling are discussed. Some of the numerical results are presented and compared with a comprehensive experimental database, wh...

Fuel droplets in combustors interact strongly with flames and turbulence in practical liquid-fueled combustors of terrestrial and aerial propulsion systems (Williams 1965; Sirignano 1999). Although a great deal of physical understanding has been achieved in purely gaseous combustion over the last century, not much is currently known about spray combustion at the fundamental level. In this short...

The reaction of the phenyl radical (C6H5) with molecular oxygen (O2) plays a central role in the degradation of poly- and monocyclic aromatic radicals in combustion systems which would otherwise react with fuel components to form polycyclic aromatic hydrocarbons (PAHs) and eventually soot. Despite intense theoretical and experimental scrutiny over half a century, the overall reaction channels h...

In order to get a methane catalytic combustion micro-sensor, two different catalytic systems used in traditional methane catalytic combustion sensors were fabricated into a mesoporous structure and their catalytic activities were investigated. In comparison, the Rh2O3-Al2O3 system can form more a uniform mesoporous structure and has a much higher specific surface area. Even more importantly, it...

Particulate matter (soot aerosol or carbon black) emissions from combustion systems have adverse effects on human health and the environment. Soot is a major contributor to the total radiation heat loss in propulsion systems. Soot aerosols in the atmosphere have significant positive radiative forcing that contributes to global warming because of strong absorption of sunlight by soot. As compare...

Lean operation of spark ignition (SI) automotive engines offers attractive performance incentives. Lowered combustion temperatures inhibit NO, pollutant formation while reduced manifold throttling minimizes pumping losses, leading to higher efficiency. These benefits are offset by the reduced combustion speed of lean mixtures, which can lead to high cycle-to-cycle variation and unacceptable eng...

The evaluation of the potential public and occupational health hazards of developing and existing combustion processes requires a detailed understanding of the physical and chemical properties of effluents available for human and environmental exposures. These processes produce complex mixtures of gases and aerosols which may interact synergistically or antagonistically with biological systems....

The combustion of straight vegetable oil (SVO) in internal combustion engines has shown conflicting results in emissions, power, and engine longevity. Many early studies suggested that SVO should not be considered for long term use in diesel engines. However, waste vegetable oil has been fueling adapted vehicles in progressive communities for years. The issues involved in the combustion of SVO ...

The small radiant heaters that burn hydrocarbon fuels propane, butane, methane/natural gas and liquid hydrocarbon fuels are used widely because of their simple design, their portability, and the ready availability of fuels. The open flame heater presents obvious disadvantages as follows. An upset heater is a grave fire risk where the surroundings are flammable and this restricts usage in, for e...