A reduced model technique based on a reduced number of numerical simulations at a subset of operating conditions for a perfectly stirred reactor is developed in order to increase the rate of convergence of a genetic algorithm (GA) used for determining new reaction rate parameters of chemical kinetics mechanisms. The genetic algorithm employed uses perfectly stirred reactor, laminar premixed fla...

Abstract Pre-ignition is an undesired combustion event known to restrict kinetic modeling validation. Previous methane oxidation studies reported premature ignition as part of delay time measurements in shock tubes. In this context, the effect on pre-ignition propensity and auto-ignition behavior stoichiometric mixtures at different dilution levels $$\hbox {N}_2$$ <mml:math xmlns:mml="http://ww...

Two new 14-step and 16-step reduced mechanisms for methane-air combustion were developed with the emphasis on their capabilities to predict NO2 formation. The systematic reduction was carried out by assuming the quasi-steady state for 26~28 species in the starting mechanism with the help of a automatic mechanism reduction code. The two reduced mechanisms reproduce NO2 formation behaviors obtain...

A one-dimensional numerical model and theoretical analysis involving both surface and in-depth radiative heat flux absorption are utilized to investigate the influence of their combination on ignition of PMMA (Polymethyl Methacrylate). Ignition time, transient temperature in a solid and optimized combination of these two absorption modes of black and clear PMMA are examined to understand the ig...

Abstract During the ignition of a swirled single-injector combustor, two phases have been identified experimentally. In first, flame penetrates injection unit, while in second, lifts off after substantial delay before stabilizing at distance from injector. This transient phenomenon is investigated using Large Eddy Simulations based on an Euler–Lagrange description liquid spray, energy depositio...

Abstract Re-ignition of aeroengine under high altitude conditions is great importance to the safety and use lean-burn engines. The present work investigated experimental numerical analysis flow re-ignition characteristics in a rectangular burner. A ring-needle type plasma actuator was developed powered by voltage nanopulsed generator with different percentage values amplitude frequencies. Flow ...

The present study focuses on the optimization in the use of non-petroleum fuel derived from waste fish oil fuels, as a replacement for petroleum diesel fuel for compression ignition engine. The study comprises of comparison between results of fish oil biodiesel-diesel blends on a compression ignition engine. Fuel properties such as viscosity, density, heat value of fuel, cetane number and a fla...

On the National Ignition Facility (NIF), hot electrons generated in laser heated Hohlraums are inferred from the >20 keV bremsstrahlung emission measured with the time integrated FFLEX broadband spectrometer. New high energy (>200 keV) time resolved channels were added to infer the generated >170 keV hot electrons that can cause ignition capsule preheat. First hot electron measurements in near ...

time-delay identification is one of the most important parameters in designing controllers. in the cases where the number of inputs and outputs in a system are more than one, this identification is of great concern. in this paper, a novel autocorrelation-based scheme for the state variable time-delay identification for multi-input multi-output (mimo) system has been presented. this method is ba...