Homogeneous charge compression ignition (HCCI) seems to be the most promising solution for gasoline engines in the light of future emissions regulations. This novel combustion technique allows for significant reduction of fuel consumption and engine-out NOX emissions at low and medium engine load/speed conditions. High heat release rate enables realization of the Otto cycle close to ideal, incr...

We study the energetic functions obtained in a simulated spark-ignited engine that incorporates cyclic variability through a quasi-dimensional combustion model. Our analyses are focused on the effects of the fuel-air equivalence ratio of the mixture simultaneously over the cycle-to-cycle fluctuations of heat release (QR) and the performance outputs, such as the power (P ) and the efficiency (η)...

The article presents the data related to the flame acquisitions in a liquid-fuel gas turbine derived burner operating in non-premixed mode under three different equivalence fuel/air ratio, which corresponds to a richer, an intermediate, and an ultra-lean condition, near lean blowout (LBO). The data were collected with two high speed visualization systems which acquired in the visible (VIS) and ...

Oxygen transport across the cathode gas diffusion layer (GDL) in polymer electrolyte membrane (PEM) fuel cells was examined by varying the O2/N2 ratio and by varying the area of the GDL extending laterally from the gas flow channel under the bipolar plate (under the land). As the cathode is depleted of oxygen, the current density becomes limited by oxygen transport across the GDL. Oxygen deplet...

Homogeneous charge compression ignition technology has exhibited high potential to reduce fuel consumption and NOx emissions over normal spark-ignition engines significantly. Optimized kinetic process technology is implemented to realize homogeneous charge compression ignition combustion in a port fuel injection gasoline engine. The combustion and emission characteristics are investigated with ...

Values of some characteristic parameters of confined explosions for LPG (Liquefied Petroleum Gas)-air quiescent mixtures are examined in correlation with the initial pressure of fuel-air mixture and fuel/air ratio. The explosion pressures, the explosion times and the maximum rates of pressure rise were obtained from experiments made at ambient initial temperature in two closed vessels with cent...

Availability changes with crank angle at the optimum engine operating point of 4000 rpm and WOT for CNG fuelling, CNG and gasoline engine operations at optimal engine conditions with the equivalence ratio Φ = 1.1, distribution of fuel availability of CNG and gasoline fuelled engine at equivalence ratio of Φ = 1.1, entropytemperature diagram for the engine optimal operating point and CNG fuellin...

More stringent Euro 6 and LEV III emission standards will immediately begin execution on 2014 and 2015 respectively. Accurate air/fuel ratio control can effectively reduce vehicle emission. The simulation of engine dynamic system is a very powerful method for developing and analysing engine and engine controller. Currently, most engine air/fuel ratio control used look-up table combined with pro...

We propose an estimator of the individual cylinder air fuel ratios in a turbocharged Diesel Engine using as only sensor the single air fuel ratio sensor placed downstream the turbine. The observer consists of a nonlinear filter designed on a physics-based time-varying model for the engine dynamics. Convergence is proven, using a Lyapounov function. Performance is studied through simulations and...