Correlations between the coefficient of variations (COV) of ion current integrals and COV of indicated mean effective pressure (IMEP) are investigated. The investigations are made to see if there is a possibility to use ion sense technique for closed loop combustion control to maximize Exhaust Gas Recirculation (EGR) level with remaining combustion stability. The engine studied in this thesis i...

We propose a simple, physically oriented model that explains important characteristics of cyclic combustion variations in spark-ignited engines. A key model feature is the interaction between stochastic, small-scale fluctuations in engine parameters and nonlinear deterministic coupling between successive engine cycles. Prior-cycle effects are produced by residual cylinder gas which alters volum...

Engine control center Legislators all over the world are specifying in­ creasingly tougher emissions limits for diesel engines. To comply with the requirements, emis­ sions from the drive system are constantly being reduced. As the engine’s brain, the engine man­ agement system (see Figure 1) controls key sys­ tems such as fuel injection, turbocharging and exhaust gas recirculation (EGR) that a...

An investigation into the isolability of the location of intake and exhaust manifold leaks in heavy duty diesel engines is presented. In particular, established fault detection and isolation (FDI) methods are explored to assess their utility in successfully determining the location of a leak within the air path of an engine equipped with exhaust gas recirculation and an asymmetric twin-scroll t...

Towards Integrated Powertrain Control for a Mild-Hybrid Urban Vehicle with a Downsized Turbo-Charged CNG Engine — Compressed natural gas (CNG) is considered as one of the most promising alternative fuels for transportation due to its ability to reduce greenhouse gas emissions (CO2, in particular) and its abundance. An earlier study from IFP has shown that CNG has a considerable potential when u...

Biogas derived from organic wastes is considered as good alternative to petroleum fuels. It can be used in compression ignition (CI) engines, because of its better mixing ability with air and clean burning nature. Biogas is produced by anaerobic digestion of various organic substances such as kitchen wastes, agricultural wastes, municipal solid wastes, cow dung etc., in absence of oxygen, which...

The growing number of vehicles on the road has led to a rapid increase in fuel consumption and toxic gas emissions, so the challenges in fuel efficiency improvement and reduction of CO2 and NOx emissions have always been on the top agenda of the automotive industry. The paper presents a feasibility study of recovering the low-pressure exhaust gas energy via by-pass connection of a scroll expand...

In this paper, the 2f/1f tunable diode laser wavelength modulation spectroscopy is used for the simultaneous measurement of concentration and temperature of CO2 in the exhaust plume of an aero engine. The suitability of the R48 spectral feature of CO2 at 1997.2 nm is discussed for this project and for further application of CO2 tomographic imaging on large-scale aero-engines. To ensure accurate...