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Showing result 1 - 5 of 47 swedish dissertations matching the above criteria.

2. 1. Modelling of Electric Arc Welding : arc-electrode coupling

   Author : Alireza Javidi Shirvan; Isabelle Choquet; Håkan Nilsson; Alexei Heintz; Högskolan Väst; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electric welding; arc welding simulation; electrode; plasma; cathode layer; sheath; arc discharge; Manufacturing and materials engineering; Produktions- och materialteknik;

   Abstract : Arc welding still requires deeper process understanding and more accurateprediction of the heat transferred to the base metal. This can be provided by CFD modelling.Most works done to model arc discharge using CFD consider the arc corealone. READ MORE

4. 2. Modelling of cathode-plasma interaction in short high-intensity electric arc : Application to Gas Tungsten Arc Welding

   Author : Alireza Javidi Shirvan; Isabelle Choquet; Håkan Nilsson; Armelle Vardelle; Högskolan Väst; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Electric arc discharge; sheath; pre-sheath; Knudsen layer; doped refractory cathode; arc-cathode coupling; Gas Tungsten Arc simulation; OpenFOAM.; Production Technology; Produktionsteknik; Manufacturing and materials engineering; Produktions- och materialteknik;

   Abstract : In arc welding the quality of the weld is strongly influenced by the thermal history of the workpiece which is itself governed by the electric arc heat source. The models for predicting weld properties thus need a good evaluation of the distribution of the heat input from thearc to the workpiece. READ MORE

5. 3. Electric arc-contact interaction in high current gasblast circuit breakers

   Author : Torbjörn Nielsen; KTH; []
   Keywords : Electric arc; Contact evaporation; Near cathode region; Metal particles; CFD; Computational fluid dynamics; MHD; Magnetohydrodynamics;

   Abstract : .... READ MORE

6. 4. Auroral Electric Fields From Satellite Observations and Numerical Modelling

   Author : Tomas Karlsson; KTH; []
   Keywords : Satellite measurements; electric fields; ionosphere; magnetosphere; diverging electric fields; downward current region; black aurora; westward travelling surge; auroral bulge; subauroral ion drifts SAID ; subauroral electric fields SAEF ; mid-latit; TECHNOLOGY; TEKNIKVETENSKAP;

   Abstract : This thesis is about electrodynamics of thehigh-latitude/auroral region of near-Earth space. The work ismainly based on electric field measurements made by the doubleprobe instrument on the Freja satellite at altitudes ofapproximately 800-1700 km, together with measurements fromother instruments on the same satellite, and ground-basedinstrumentation. READ MORE

7. 5. On the polymer-based nanocomposites for electrical switching applications

   Author : Venkatesh Doddapaneni; Muhammet Sadaka Toprak; Hans Edin; Rudolf Gati; Matti Ilmari Lehtonen; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Polymer-based nanocomposites; Inorganic nanoparticles; Electrical arcs; Circuit breakers; Ablation Outgassing; Arc interruption capability; PMMA; CuO; Fe3O4; ZnO; Au; Radiative energy; Electric power; Arc temperature.; Physics; Fysik;

   Abstract : Recent research demonstrated that polymer based nanocomposites (PNCs) have been engineered in order to improve the arc interruption capability of the circuit breakers. PNCs are the combination of nano-sized inorganic nanoparticles (NPs) and polymers, opened up new developments in materials science and engineering applications. READ MORE