Documents disponibles écrits par cet auteur

Design principles and measured performance of multistage radial flow microturbomachinery at low Reynolds numbers / Changgu Lee in Transactions of the ASME . Journal of fluids engineering, Vol. 130 N° 11 (Novembre 2008) 

Public ISBD [article]  in Transactions of the ASME . Journal of fluids engineering > Vol. 130 N° 11 (Novembre 2008) . - 11 p. Titre : Design principles and measured performance of multistage radial flow microturbomachinery at low Reynolds numbers Type de document : texte imprimé Auteurs : Changgu Lee, Auteur ; Selin Arslan, Auteur ; Frechette, Luc G., Auteur Année de publication : 2009 Article en page(s) : 11 p. Note générale : Fluids engineering Langues : Anglais (eng) Mots-clés : Pressure;  flow  (Dynamics);  Reynolds  number;  design;  microturbines;  rotors;  turbines;  blades Résumé : This paper introduces and experimentally demonstrates the design concept of multistage microturbomachinery, which is fabricated using silicon microfabrication technology. The design process for multistage microscale turbomachinery based on meanline analysis is presented, along with computational fluid dynamics predictions of the key aerodynamic performance parameters required in this design process. This modeling was compared with a microturbine device with a 4 mm diameter rotor and 100 μm chord blades, based on microelectromechanical system technology, which was spun to 330,000 rpm and produced 0.38 W of mechanical power. Modeling suggests a turbine adiabatic efficiency of 35% and Re=266 at the maximum speed. The pressure distribution across the blade rows was measured and showed close agreement with the calculation results. Using the model, the microturbine is predicted to produce 3.2 W with an adiabatic efficiency of 63% at a rotor speed of 1.1×106 rpm. En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...] [article] Design principles and measured performance of multistage radial flow microturbomachinery at low Reynolds numbers [texte imprimé] / Changgu Lee, Auteur ; Selin Arslan, Auteur ; Frechette, Luc G., Auteur . - 2009 . - 11 p. Fluids engineering Langues : Anglais (eng) in Transactions of the ASME . Journal of fluids engineering > Vol. 130 N° 11 (Novembre 2008) . - 11 p. Mots-clés : Pressure;  flow  (Dynamics);  Reynolds  number;  design;  microturbines;  rotors;  turbines;  blades Résumé : This paper introduces and experimentally demonstrates the design concept of multistage microturbomachinery, which is fabricated using silicon microfabrication technology. The design process for multistage microscale turbomachinery based on meanline analysis is presented, along with computational fluid dynamics predictions of the key aerodynamic performance parameters required in this design process. This modeling was compared with a microturbine device with a 4 mm diameter rotor and 100 μm chord blades, based on microelectromechanical system technology, which was spun to 330,000 rpm and produced 0.38 W of mechanical power. Modeling suggests a turbine adiabatic efficiency of 35% and Re=266 at the maximum speed. The pressure distribution across the blade rows was measured and showed close agreement with the calculation results. Using the model, the microturbine is predicted to produce 3.2 W with an adiabatic efficiency of 63% at a rotor speed of 1.1×106 rpm. En ligne : http://fluidsengineering.asmedigitalcollection.asme.org/issue.aspx?journalid=122 [...]

A low-power stand-alone adaptive circuit for harvesting energy from a piezoelectric micropower generator / Tabesh, Ahmadreza in IEEE transactions on industrial electronics, Vol. 57 N° 3 (Mars 2010) 

Public ISBD [article]  in IEEE transactions on industrial electronics > Vol. 57 N° 3 (Mars 2010) . - pp. 840 - 849 Titre : A low-power stand-alone adaptive circuit for harvesting energy from a piezoelectric micropower generator Type de document : texte imprimé Auteurs : Tabesh, Ahmadreza, Auteur ; Frechette, Luc G., Auteur Article en page(s) : pp. 840 - 849 Note générale : Génie électrique Langues : Anglais (eng) Mots-clés : Energy  harvesting  Energy  scavenging  Low-power  energy  conversion  Piezoelectric  generator  Power  management  circuit  Stand-alone  energy  harvester Index. décimale : 621.38 Dispositifs électroniques. Tubes à électrons. Photocellules. Accélérateurs de particules. Tubes à rayons X Résumé : An adaptive energy-harvesting circuit with low power dissipation is presented and demonstrated, which is useful for efficient ac/dc voltage conversion of a piezoelectric micropower generator. The circuit operates stand-alone, and it extracts the piezoelectric strain energy independent of the load and piezoelectric parameters without using any external sensor. The circuit consists of a voltage-doubler rectifier, a step-down switching converter, and an analog controller operating with a single supply voltage in the range of 2.5-15 V. The controller uses the piezoelectric voltage as a feedback and regulates the rectified voltage to adaptively improve the extracted power. The nonscalable power dissipation of the controller unit is less than 0.05 mW, and the efficiency of the circuit is about 60% for output power levels above 0.5 mW. Experimental verifications of the circuit show the following: 1) the circuit notably increases the extracted power from a piezoelectric element compared to a simple full-bridge diode rectifier without control circuitry, and 2) the efficiency of the circuit is dominantly determined by its switching converter. The simplicity of the circuit facilitates the development of efficient piezoelectric energy harvesters for low-power applications such as wireless sensors and portable devices. DEWEY : 621.38 ISSN : 0278-0046 En ligne : http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5345727 [article] A low-power stand-alone adaptive circuit for harvesting energy from a piezoelectric micropower generator [texte imprimé] / Tabesh, Ahmadreza, Auteur ; Frechette, Luc G., Auteur . - pp. 840 - 849. Génie électrique Langues : Anglais (eng) in IEEE transactions on industrial electronics > Vol. 57 N° 3 (Mars 2010) . - pp. 840 - 849 Mots-clés : Energy  harvesting  Energy  scavenging  Low-power  energy  conversion  Piezoelectric  generator  Power  management  circuit  Stand-alone  energy  harvester Index. décimale : 621.38 Dispositifs électroniques. Tubes à électrons. Photocellules. Accélérateurs de particules. Tubes à rayons X Résumé : An adaptive energy-harvesting circuit with low power dissipation is presented and demonstrated, which is useful for efficient ac/dc voltage conversion of a piezoelectric micropower generator. The circuit operates stand-alone, and it extracts the piezoelectric strain energy independent of the load and piezoelectric parameters without using any external sensor. The circuit consists of a voltage-doubler rectifier, a step-down switching converter, and an analog controller operating with a single supply voltage in the range of 2.5-15 V. The controller uses the piezoelectric voltage as a feedback and regulates the rectified voltage to adaptively improve the extracted power. The nonscalable power dissipation of the controller unit is less than 0.05 mW, and the efficiency of the circuit is about 60% for output power levels above 0.5 mW. Experimental verifications of the circuit show the following: 1) the circuit notably increases the extracted power from a piezoelectric element compared to a simple full-bridge diode rectifier without control circuitry, and 2) the efficiency of the circuit is dominantly determined by its switching converter. The simplicity of the circuit facilitates the development of efficient piezoelectric energy harvesters for low-power applications such as wireless sensors and portable devices. DEWEY : 621.38 ISSN : 0278-0046 En ligne : http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=5345727