In this study it has been tried, to compare results and convergence rate of sensitivity analysis and conjugate gradient algorithms to reduce fuel consumption and increasing engine performance by optimizing the timing of opening and closing valves in XU7/L3 engine. In this study, considering the strength and accuracy of simulation GT-POWER software in researches on the internal combustion engine...

in this study it has been tried, to compare results and convergence rate of sensitivity analysis and conjugate gradient algorithms to reduce fuel consumption and increasing engine performance by optimizing the timing of opening and closing valves in xu7/l3 engine. in this study, considering the strength and accuracy of simulation gt-power software in researches on the internal combustion engine...

The timing of the valves of a hydraulic motor plays an important role in determining the throttling energy. To reduce this dominating energy loss, the timing of the valves must allow the fluid in the chamber to be precompressed and decompressed such that there is minimal pressure differential across the transitioning valve. The optimal valve timing to achieve precompression and decompression is...

nowadays, due to increasing the complexity of ic engines, calibration task becomes more severe and the need to use surrogate models for investigating of the engine behavior arises. accordingly, many black box modeling approaches have been used in this context among which network based models are of the most powerful approaches thanks to their flexible structures. in this paper four network base...

The effects of spark timing and exhaust valve timing change on exhaust gas temperature during cold start of an SI engine are studied through engine bench tests. It is observed that the exhaust gas temperature increases when the spark timing and valve timing are retarded individually or simultaneously, due to late combustion or slow flame speed. However, using COVimep it is also investigated tha...

Small diesel engines are widely used for commercial vehicle and passenger car applications due to their higher torque requirements, fuel economy, and better thermal efficiency. These engines are exposed to different operating and environmental conditions and hence emissions from these engines are erratic. Strategies are required to enhance performance and reduce engine-out emissions considering...

The tests were carried out with the spark timing adjusted to the maximum brake torquetiming in various equivalence ratios and engine speeds for gasoline and natural gas operations. In thiswork, the lower heating value of gasoline is about 13.6% higher than that of natural gas. Based on theexperimental results, the natural gas operation causes an increase of about 6.2% brake special fuelconsumpt...

In order to investigate relations between mitral valve closure and mechanical events at the onset of left ventricular systole, simultaneous M mode echocardiograms and phonocardiograms were recorded with the apexcardiogram and its first differential (dA/dt) in 25 normal subjects and 88 patients with heart disease. The timing of mitral and aortic valve closure and the onset and peak rate of rise ...

In an electro-mechanical valve actuated engine, solenoid actuators drive the valves that control airflow into the cylinders, allowing elimination of the camshaft and flexible control of the valve timing. Individual control of the valves provides flexibility in valve timing over all engine operating conditions and fully enables the benefits of variable valve timing. This paper describes a closed...