Two virtual sensors are proposed that use the spark-plug based ion current sensor for combustion engine control. The first sensor estimates combustion variability for the purpose of controlling exhaust gas recirculation (EGR) and the second sensor estimates the pressure peak position for control of ignition timing. Use of EGR in engines is important because the technique can reduce fuel consump...

Lean fuel/air mixtures with various fuel/fuel ratios between methane and n-butane were supplied to a premixed compression-ignition engine (i.e. homogeneous charge compression ignition engine, HCCI) with or without supplementary gaseous formaldehyde induction as an ignition controlling additive. In the no additive case the methane and butane function as the two fuels in the high/low-octane two-f...

Combustion analysis has been conducted on a small two-stroke glow ignition engine, which has similar combustion characteristics to homogeneous charge compression ignition (HCCI) engines. Difficulties such as unknown ignition timing and the polytropic index have been addressed by combining both heat release and mass fraction burn analyses. Results for all operating conditions have shown good cor...

A large eddy simulation (LES) model was developed to simulate the combustion process in a spark-assisted homogeneous charge compression ignition (SACI) engine. First, an ignition and flame propagation model based on a reaction progress variable is presented. The reaction progress variable is defined based on the normalized cumulative heat release. Transport equation for the progress variable is...

Experiments were conducted to evaluate the performance of a low heat rejection (LHR) diesel engine. Performance parameters and emission levels were determined at various magnitudes of brake mean effective pressure. Combustion characteristics of the engine were measured with TDC (top dead centre) encoder, pressure transducer, console and special pressure-crank angle software package at peak load...

In this study, the thermodynamic performance of a turbocharged compression ignition engine with heat transfer and friction term losses was analyzed. The purpose of this work was to provide a flexible thermodynamic model based on the filling-and-emptying approach for the performance prediction of a four-stroke turbocharged compression ignition engine. To validate the model, comparisons were made...

In this paper we consider signal processing algorithms for detecting knock, i.e. auto-ignition of unburned fuel, in spark-ignited engines. To operate an engine with optimal efficiency, there is a need to operate close to the knock limit. This motivates the need for efficient knock detection algorithms that not only indicates knock, but also gives estimates on knock timing and size. The proposed...

An experimental study is carried out to investigate engine performance parameters and methods of reducing emissions from spark ignition engine. The used engine is four stroke four cylinder naturally aspirated spark ignition engine with compression ratio of 9, bore diameter of 80 mm and stroke of 90 mm. The engine performance parameters are presented with and without exhaust gases recirculation ...