Search for: volumetric-efficiency
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    Observer Design for Exhaust Manifold Pressure in Turbocharged SI Engines

    , M.Sc. Thesis Sharif University of Technology Hassani Monir, Vahid (Author) ; Alasty, Aria (Supervisor) ; Vossoughi, Gholamreza (Supervisor)
    Nowadays, fuel optimum used in engines is an important matter. To achieve this aim, we need to tune engine. The big companies have paid attention to these cases. Because of it, there are strict standard in the world and in other side the internal combustion engine is very common.
    In the internal combustion engine after cylinder, the gas inter to an encasement which is called exhaust manifold. In the other hand, exhaust manifold is in upstairs of turbine and waste-gate in turbocharged SI engines. To control fuel used and descries the amount of emissions, exhaust manifold pressure is very important. In the other hand, monitoring of exhaust manifold pressure can use for fault detection of... 

    A novel revolving piston minipump

    , Article Sensors and Actuators, B: Chemical ; Volume 218 , October , 2015 , Pages 237-244 ; 09254005 (ISSN) Ashouri, M ; Shafii, M. B ; Moosavi, A ; Amiri Hezave, H ; Sharif University of Technology
    Elsevier  2015
    In this study, a novel prototype high-efficiency miniature pump that uses magnetic properties of a ferrofluid in both pumping and valving mechanisms is presented. The minichannel consisting of a cylindrical pumping chamber, a check valve, an inlet and an outlet, comprises six bonded layers of PMMA. A cylindrical permanent magnet that is placed inside the chamber and is externally actuated by a motorized off-center permanent magnet, functions as a revolving piston which sweeps the perimeter of the cylinder. Ferrofluid is used to cover the gaps between the magnetic piston and the channel walls, also serves as a separating plug between the inlet and the outlet of the chamber preventing... 

    Real-time estimation of the volumetric efficiency in spark ignition engines using an adaptive sliding-mode observer

    , Article Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering ; Volume 229, Issue 14 , December , 2015 , Pages 1925-1933 ; 09544070 (ISSN) Hassani Monir, V ; Salehi, R ; Salarieh, H ; Alasty, A ; Vossoughi, G ; Sharif University of Technology
    SAGE Publications Ltd  2015
    Proper operation of an engine requires accurate measurement or estimation of the engine's air charge provided to the control unit which reduces both the engine's fuel consumption and the emissions. The volumetric efficiency of the engine is a key variable in computations using the engine control unit to estimate the air charge using the speed-density equation. This paper presents a new approach for real-time estimation of the volumetric efficiency using the sliding-mode methodology. An adaptive sliding-mode observer is proposed which relies on measurements from the engine's conventional sensors. The observer is shown to estimate asymptotically the volumetric efficiency of the engine for... 

    Prediction of stratified charge divided chamber engine performance

    , Article Scientia Iranica ; Volume 16, Issue 1 , 2009 , Pages 92-100 ; 10263098 (ISSN) Tiourad, M ; Mozafari, A ; Sharif University of Technology
    Certain stratified charge divided chamber engines have a very small pre-chamber, equipped with a spark plug and a main chamber connected to the pre-chamber through nozzles, A theoretical model is presented in this research to predict ignition delay and initiation of combustion in the pre-chamber. It considers flame progress in the pre-chamber up to the point where the flame penetrates the main chamber through the connecting nozzles. Step by step calculations then continue in the main chamber and the mass fraction burned and the energy release rate are calculated. The process continues to the point where all the fuel is burned. At each step, due to a one degree rotation of the crank shaft,... 

    Theoretical and experimental studies of a magnetically actuated valveless micropump

    , Article Journal of Micromechanics and Microengineering ; Volume 27, Issue 1 , 2017 ; 09601317 (ISSN) Ashouri, M ; Shafii, M. B ; Moosavi, A ; Sharif University of Technology
    Institute of Physics Publishing  2017
    This paper presents the prototype design, fabrication, and characterization of a magnetically actuated micropump. The pump body consists of three nozzle/diffuser elements and two pumping chambers connected to the ends of a flat-wall pumping cylinder. A cylindrical permanent magnet placed inside the pumping cylinder acts as a piston which reciprocates by using an external magnetic actuator driven by a motor. The magnetic piston is covered by a ferrofluid to provide self-sealing capability. A prototype composed of three bonded layers of polymethyl-methacrylate (PMMA) has been fabricated. Water has been successfully pumped at pressures of up to 750 Pa and flow rates of up to 700 μl min-1 while...