Search results for " MOTOR"
showing 10 items of 1044 documents
Propellant non-steady burning effects on controllable solid rocket motor internal ballistics
2009
An analysis of the unsteady non-linear behavior of the controllable solid propellant rocket motor (CSRM) consequent to rapid and relevant nozzle operation is presented. The study includes a development of a non-linear unsteady combustion model able to handle relevant and rapid chamber pressure changes typical of CSRMs. The CSRM nonlinear unsteady model is implemented according to a main solver - sub models architecture and uses different time scales. The formulation of the combustion gas mass flow rate is developed considering the propellant density, the unsteady combustion, the regression of the combustion surface and the outflow through the variable nozzle. The grain surface involved in t…
An Experimental Study of In-Cylinder Heat Transfer from a Pressurized Motored Engine with Varying Peak Bulk Gas Temperatures
2022
The variation of in-cylinder heat transfer with parameters such as engine speed, air-to-fuel ratio, coolant temperature and compression ratio were frequently studied in classical research. These experimentally-obtained relationships are important for improving in-cylinder heat transfer models, essential in developing CO2 reducing strategies. In this publication, a 2.0 liter compression ignition engine was tested in the pressurized motored configuration. This developed experimental setup allowed testing of the engine at speeds ranging between 1400 rpm and 3000 rpm, with peak in-cylinder gas pressures from 40 bar to 100 bar. The engine was motored using different gas compositions chosen speci…
Modello dinamico di iniettore di gas per motore ad accensione comandata
2010
Nel presente lavoro si studia la complessa dinamica dell’otturatore di un iniettore di gas a solenoide per motori ad accensione comandata; come è noto, esso è sottoposto a spinte di diversa natura ed il suo moto ha un influenza determinante nei confronti della massa di combustibile erogata, la quale viene di norma modulata intervenendo sulla durata dell’intervallo di eccitazione del solenoide, chiamato “tempo di iniezione”. Ad otturatore completamente aperto, la massa di gas che attraversa la sezione di uscita dell’iniettore dipende esclusivamente dalle condizioni del fluido a monte dell’iniettore e dalla durata del tempo di iniezione: ciò rende lineare la caratteristica di funzionamento de…
A Ferrite Tubular Linear Motor (FTLM): Analysis and design
2015
The electromagnetic linear machines have wide applications in the electromagnetic aircraft launch systems [1] and in transportation systems [2]. Additional energy saving and efficiency can be achieved using a linear motor in the refrigeration application [3]. Linear electromagnetic machines are also very suitable for high-speed packaging, manufacturing sectors and precision positioning. There are different linear motor topologies. Tubular permanent-magnets are particularly attractive since they have a high thrust force density and high efficiency, no end windings, and zero net attractive force between stator and armature. There are various tubular motor topologies, in which the armature may…
Design and Test of a Thermomagnetic Motor Using a Gadolinium Rotor
2013
The purpose of this paper is to show that a Thermomagnetic (Curie) Motor [1-3], which can rotate continuously and has useful mechanical characteristics, is feasible. A thermomagnetic motor can directly converts thermal energy into kinetic energy. In this type of motor force is generated by a thermally induced permeability difference in two areas of the rotor, which can generate a force if the rotor is placed in a magnetic field. This force can be enhanced if the hot side temperature of the rotor is above the Curie’s temperature of the magnetic material and the cold side under this temperature Unfortunately, the traditional ferromagnetic materials have very high Curie’s temperature and there…
Optimization of a thermomagnetic motor
2015
In this paper, an approach towards the optimization of the Curie motor is presented. The approach is based on a thermal-magnetic coupled dynamic model of the motor, which is obtained by assuming the use of a ferromagnetic material working at temperatures near the Curie point. An analytical expression of the generated torque, which links this quantity to the magnetic, thermal, and geometrical parameters of the generated torque, is given. The expressions of speed and torque are derived and related to the thermal properties of the machine and are used as optimization indexes in an optimization procedure. The aim of the optimization process is to obtain a machine able to rotate constantly at th…
STUDIO DI UNA FRIZIONE MAGNETOREOLOGICA PER AUTOVEICOLI
2013
Dopo un’accurata ricerca bibliografica sui fluidi magnetoreologici, il loro comportamento ed impiego, si è passati alla progettazione di una frizione magnetoreologica per autoveicoli. Considerando le caratteristiche di coppia trasmessa e potenza, il dispositivo è stato dimensionato tenendo presente i vincoli di ingombro del veicolo preso in esame. Sottoponendo il dispositivo ad analisi magnetostatica agli elementi finiti, si è determinato l’andamento delle linee di flusso del campo magnetico nel meato di fluido e nelle zone di maggior interesse, calcolando la coppia teoricamente trasmessa dall’innesto.È stato anche eseguito il confronto delle prestazionifra una frizione MR ed una frizione t…
Comfort-structural analysis in product development Optimization of a motorcycle frame
2012
This work steps from a bachelor thesis, joining the results of a study about the dynamic loads to evaluate the comfort loss in the motorcycle during the usage, with the potentiality of a modern FEM software. The goal is the development of a new methodology for structural optimization of motorcycle’s frame. In many of cases the success of the structural optimization is linked with a two factors combination: the software and the strength of the engineer to condition the mathematical problem, defining parameters domain and technological constraints. A good alternative to the traditional load hypothesis linked to historical data or instrumental measurements is focused in this paper. Consistent …
Energia da gradienti salini: dall’acqua l’energia del futuro
2017
Today, continuous research efforts are aimed at finding alternative renewable energy sources to conventional ones and efficient technologies able to exploit them. Saline gradient energy is an unconventional renewable energy source widely available and currently under-exploited. In the present document the most technologies are illustrated avant-garde for the conversion of this energy into electric current: Pressure Retarded Osmosis, PRO (Osmosis Delayed by Pressure) and the Reverse Electrodialysis, RED (Inverse Electrodialysis).
Experimental investigation on high-efficiency control algorithms for three-phase induction motors
2020
This paper presents an experimental investigation regarding the power losses variations occurring in three-phase induction motors (IMs) as a function of the magnetization level of the machine. More in detail, the power losses identification is obtained by changing in real-time the working operating conditions of the IM drive and the IM reference flux. The sets of measurements are carried out by setting up a test bench and the obtained results confirm that the power losses occurring in induction motors can be minimized by adequately setting the direct axis current component for each IM working condition. This research represents the starting point for the conception of advanced real-time los…