The experimental study was conducted to investigate the effects of different opening ranges of waste gate of a turbocharged medium displacement spark ignition engine on improving work parameters such as exhaust emission, torque characteristics and fuel consumption. The object of the experimental tests was an engine with modified intake and exhaust manifolds. The intake and exhaust manifold modi...

A novel approach that allows control of flow in microfluidic channels with unsurpassed performance using light is described. Valve structures have been created using photoresponsive hydrogels based on spiropyran-functionalised pNIPAAm hydrogels photopolymerised around pillar structures within the channels. Valve actuation is controlled from outside the fluidic system using externally located LE...

Original scientific paper The necessary forces for the control of a hydraulic sliding-spool valve are normally determined by the stationary axial momentum forces of the oil flow through a valve. These forces increase with an increase in the volume flow and the pressure difference. Because of the limited actuating-force potential of normal electromechanical actuators, the direct actuation of con...

Next level of passenger vehicles engines evolution is needed to comply with fuel economy and pollutant regulation legislative requirements. Turning a combustion engine with modern control systems into reverse uniflow two-stroke engines improves the power density of the engine and minimizes negative aspects of using the classic two-stroke engines. Variable valve timing allows control of the inta...

In this paper, the effect of the Intake Valve Deactivation (IVDA) on engine performance is investigated in detail. Based on an optimization platform with Genetic Algorithm (GA) and engine thermodynamic model, the characteristics of the engine volumetric efficiency and pumping loss were studied under the cam-drive, Single Intake Valve (SIV) and Dual Intake Valves (DIV) operating modes, and the e...

A three-dimensional CFD modeling was carried out to investigate effects of VVT/VVA on gas exchange and fuel-air mixing processes in a diesel HCCI engine with early fuel injection. Four VVT/VVA strategies were conducted for this study: i) NVO strategy with fixed EVO and IVC timings but variable valve lifts – referred as NVO Strategy; ii) NVO strategy with fixed valve profiles but variable EVO an...