Overall Performance Of Engine Research Articles

Knock detection based on the optimized variational mode decomposition

In order to extract slight characteristics and achieve exact control of engine knock to improve the overall performance of engine, the optimized Variational Mode Decomposition (VMD) algorithm is introduced to process the vibration signals of engine. Combined with recursive model and energy difference tracking method, the optimized VMD can decompose signals into several modes based on stop criterion instead of artificial values set in advance. Besides, the initial values of center frequencies are also optimized for stability and efficiency. An analog signal is firstly decomposed by this method, and result shows that the optimized VMD has ability to extract components accurately. Then this method is applied for the decomposition of tested engine vibration signals and compared with the Empirical Mode Decomposition (EMD) and traditional VMD, the results show that the optimized VMD can eliminate effect of noise and extract knock at different intensities more accurately and quickly.

Assessment of the fuel magnetisation capacity to improve fuel economy and enhance performance in a four-stroke SI engine

In this paper, we investigate the effect of fuel magnetisation on the overall performance of a four-stroke Spark Ignition (SI) engine. To achieve this objective, we have designed a set of experiments using the Mitsubishi 1.5 L (4G15) SI engine. Each experiment is performed in two phases: with and without the fuel magnetisation. The collected data was analysed to assess the overall performance of the engine at several operating conditions. Our study shows that fuel magnetiser can enhance the overall performance of a typical SI engine. However, the enhancement greatly depends on the operating condition of the engine. Specifically, the best-observed performance enhancement in the tested engine owing to the usage of the fuel magnetiser was to reduce the Brake Specific Fuel Consumption (BSFC) by 9%, increase the Brake Power (BP) by 9% and boost the brake thermal efficiency (ηb) from 29% to 31%.