Search for dissertations about: "surge"

Showing result 1 - 5 of 135 swedish dissertations containing the word surge.

  2. 1. On Stability and Surge in Turbocharger Compressors

    Author : Bertrand Kerres; Andreas Cronhjort; Mihai Mihaescu; Jörg Seume; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbocharger; Radial Compressor; Stability; Surge; Hurst exponent; Fractals; Machine Design; Maskinkonstruktion;

    Abstract : Turbochargers are used on many automotive internal combustion engines to increase power density. The broad operating range of the engine also requires a wide range of the turbocharger compressor. At low mass flows, however, turbo compressor operation becomes unstable and eventually enters surge. READ MORE

  4. 2. Analysis of High-Frequency Electrical Transients in Offshore Wind Parks

    Author : Tarik Abdulahovic; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; restrikes; very fast transient; surge protection; surge; voltage escalation; transient overvoltage; prestrikes; breaker;

    Abstract : In this thesis, a study of high frequency electromagnetic transient phenomena is performed. Models of various components needed for simulations of high frequency transients, such as transformers, cables and breakers are developed. READ MORE

  5. 3. Analysis of High-Frequency Electrical Transients in Offshore Wind Parks

    Author : Tarik Abdulahovic; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; very fast transient; surge protection; surge; transient overvoltage; restrikes; prestrikes; breaker; voltage escalation;

    Abstract : In this thesis, a study of high frequency electromagnetic transient phenomena is performed. Models of various components needed for simulations of high frequency transients, such as for transformers, cables and breakers are developed. READ MORE

  6. 4. Flow instabilities in centrifugal compressors at low mass flow rate

    Author : Elias Sundström; Mihai Mihaescu; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Centrifugal compressor; flow instabilities; rotational flows; rotating stall; surge; compressible Large Eddy Simulation; Engineering Mechanics; Teknisk mekanik;

    Abstract : A centrifugal compressor is a mechanical machine with purpose to convert kineticenergy from a rotating impeller wheel into the fluid medium by compressingit. One application involves supplying boost air pressure to downsized internalcombustion engines (ICE). READ MORE

  7. 5. Dead-Ice Under Different Climate Conditions: Processes, Landforms, Sediments and Melt Rates in Iceland and Svalbard

    Author : Anders Schomacker; Kvartärgeologi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; klimatologi; glacier; dead-ice; surge; ice-cored; Little Ice Age; fysisk geografi; Geologi; Geology; Svalbard; Iceland; Sedimentology; cartography; pedology; geomorphology; Sedimentologi; Physical geography; geomorfologi; marklära; kartografi; climatology;

    Abstract : Modern dead-ice environments in the glacier forefields of Brúarjökull, Iceland and Holmströmbreen, Svalbard were investigated with focus on landform and sediment genesis, as well as quantification of melting. Field monitoring and studies of multi-temporal aerial photographs, satellite imagery, and Digital Elevation Models (DEMs) provided data for the melting quantification. READ MORE