Turbulent jet ignition (TJI) is a promising strategy to ignite diluted air-fuel mixtures; this usually generated by igniting fraction of the mixture inside small pre-chamber. Nevertheless, processes that take place pre-chamber, as well injection turbulent into main chamber and its subsequent re-ignition are not fully understood. The current work presents an experimental investigation studies effects nozzle size, turbulence level, on pre-chamber combustion. To accomplish this, series...

An optically accessible pre-chamber setup was used to investigate the ignition occurrence and early flame propagation in methane/air mixtures at density conditions relevant engine application. Two Schlieren setups coupled with fast recording cameras allowed visualization of combustion chamber a close up location, respectively. A spectroscopy-based diagnostic simultaneously applied characterize mixture composition near spark plug. Nanosecond Repetitively Pulsed Discharge (NRPD) different...

The present work reports a one-dimensional model to predict the liquid length and spray penetration of diesel sprays when using blends single-component fuels. A high-pressure liquid-vapour equilibrium has been implemented by means fugacity coefficients, together with hypothesis real-gas mixture calculate partial enthalpy each component. validated in first step an experimental study binary n-decane n-hexadecane, where temporal evolution vapor have measured. Results show that predicts...

The optimization of the combustion process in spark ignition engines has led to novel strategies ignite lean and low reactivity mixtures, such as application turbulent jet Nanosecond Repetitively Pulsed Discharge (NRPD) systems Turbulent Jet Ignition (TJI). In present experimental work, an optically accessible setup was used investigate occurrence early flame development pre-chamber subsequent main chamber methane/air mixtures at density conditions relevant engine application. Two schlieren...

In the present work, numerical simulations are carried out to investigate underexpanded methane jets with phase separation effects. order predict fuel injection and mixture formation in constant volume chamber, a hybrid, pressure-based solver is combined vapor-liquid equilibrium model moving mesh methodology. The thermodynamic models based on cubic equation of state Soave, Redlich, Kwong. A compressibility correction for widely known kωSST turbulence implemented additionally....

Lean-premixed gas combustion is an attractive option for meeting future emission standards toward considerably lower particulate matter and emissions while obtaining efficiency comparable to diesel combustion. However, ignition processes still pose considerable challenges, with pre-ignition being a major issue. The phenomenon might result from the self-ignition of lube oil in hot zones, making it challenging observe real engines. To study single or sparsely separated droplets under...

Natural gas is a promising alternative fuel for internal combustion engines, it allows reduction of engine-out emissions without impairing high engine efficiencies. Although this approach already utilized from small to large classes, almost exclusively based on the premixed, homogeneous charge. For ignition, engines use standard spark-plugs or pre-chambers, while and lean-operated pre-chambers pilot injections. Direct high-pressure injection more recent, way operate which offers benefits...

This work presents a joint experimental and numerical study of global characteristics mixing behavior underexpanded methane jets at high-pressure conditions in Constant Volume Chamber. Injection pressures 200, 250, 300 bar pressure ratios 4, 5, 6, 8, 10 each those have been investigated. Tracer LIF with acetone as tracer has applied to experimentally quantify the quiescent air. In order exploit symmetry configuration, accompanying simulations carried out Reynolds-Averaged Navier-Stokes...

Natural gas is a promising alternative fuel for internal combustion engines, it allows reduction of engine-out emissions without impairing high engine efficiencies. Although this approach already utilized from small to large classes, almost exclusively based on the premixed homogeneous charge. For ignition, engines use standard spark plugs or pre-chambers, while and lean-operated pre-chambers pilot injections. Direct high-pressure injection more recent, way operate which offers benefits...

Due to stringent emission regulations, it is of practical significance understand cycle-to-cycle variations in the combustion fossil or renewable fuels reach future regulations. The present study aims conduct a parametric investigation analyse influence valve lift and different mass flows an inlet test engine “Flex-OeCoS” on flow structures. To gain deeper understanding behaviour, optical bench for 2D Particle Image Velocimetry (PIV) Large Eddy Simulation (LES) are used. Turbulence phenomena...

Combustion chamber wall heat transfer is a major contributor to efficiency losses in diesel engines. In this context, thermal swing materials (adapting the surrounding gas temperature) have been pinpointed as promising mitigative solution. study, experiments are carried out high-pressure/high-temperature vessel (a) characterise process ensuing from impingement of combusting fuel spray, and (b) evaluate insulative improvements provided by coating that promotes swing. The baseline experimental...

Understanding cycle-to-cycle variations (CCV) is of practical importance for the combustion fossil and renewable fuels, as increasingly stringent emission regulations require reductions in negative effects such variations. The subject this study flow around inlet valves, since oscillations flows affect structure cylinder are thus one causes CCV. To end, a parametric analysis influences mass rate valve lift two parallel engine intake valves on structures performed. This follows from an...

This work constitutes a numerical investigation of the autoignition underexpanded methane jets at high-pressure conditions. Injection pressures from 125 to 500 bar, back 40 and pressure ratios between 2.5 10 have been targeted. The aim is identify effect main control variables gas injection on delay location. To this end, Reynolds-Averaged Navier-Stokes simulations with k-ωSST model carried out for five broad parametric variations. computational domain represents Constant Volume Cell...

In the transportation industry, use of alternative fuels as well implementation new combustion strategies have a main role for its development. this study, both been combined with aim to determine limits lean under different oxygen concentrations. The study Turbulent Jet Ignition (TJI) has carried out in an optical pre-chamber (OPC) which accesses (PC) and chamber (MC). Therefore, whole process can be characterized using methane hydrogen. Their behaviour studied by analysing highspeed...