Sökning: "transient measurements"

Visar resultat 6 - 10 av 289 avhandlingar innehållade orden transient measurements.

  1. 6. FLOW FIELD IN A HIGH HEAD FRANCIS TURBINE DRAFT TUBE DURING TRANSIENT OPERATIONS

    Författare :Rahul Goyal; Michel J. Cervantes; Bhupendra K. Gandhi; Gabriel Ciocan; Lisa Prahl; Ramis Orlu; Gunilla Andree; Andrea Toffolo; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Francis turbine; Steady state; Transient; Particle Image Velocimetry; Vortex Rope; Strömningslära; Fluid Mechanics;

    Sammanfattning : Hydroelectricity plays an important role to balance the stability of grid network.  In order to improve the stability of presently high loaded grids, hydropower plants are being operated over a wide range of operations and experiencing frequent start-stop, load rejection, and load acceptance. LÄS MER

  3. 7. Stability and Statistical Analysis of Transient Waves in Fusion Plasmas

    Författare :Gergö Pokol; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; short-time Fourier transform; transient MHD mode; wavelet transform; quasi-linear diffusion; runaway electron; transient transport; stellarator; tokamak disruption; fusion plasma physics; whistler wave;

    Sammanfattning : Thermonuclear energy generation in magnetically confined plasmas offers an appealing energy source for coming generations. Some of the still unsolved problems in fusion plasma physics involve plasma transport and stability of plasma waves. Two such problems are addressed in the present thesis. LÄS MER

  4. 8. Studies on Building Air Leakage -a transient pressurisation method, measurements and modelling

    Författare :Björn Mattsson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; air change rate; Airtightness; CFD-simulations; moisture transport; air leakage; mould growth; cold attics; transient pressurisation;

    Sammanfattning : Airtightness of the building envelope is a key factor for good performance of a building. The main part of this thesis deals with the exploration of a transient pressurisation method for air leakage measurements.In the transient method, an enclosure is pressurised to a desired pressure. The air flow into the enclosure is then stopped. LÄS MER

  5. 9. Stability of Low-Frequency AC Railways : Models and Transient Stability

    Författare :John Laury; Lars Abrahamsson; Math Bollen; Pablo Arboleya; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electric Power Engineering; Elkraftteknik;

    Sammanfattning : Low-frequency AC railway grids are unique in the sense that a only few countries around the world uses them, still however, they are an important parts of their countries infrastructures. Due to the usage of a dierent frequency than the public grid of the country, conversion of frequency is needed for the interconnection. LÄS MER

  7. 10. An experimental investigation of flow in a Kaplan runner : steady-state and transient

    Författare :Kaveh Amiri; Bjarne Børresen; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strömningslära; Fluid Mechanics;

    Sammanfattning : Water turbines are since some years widely used for grid stabilization purposes according to their exceptional load variation capability which gives them the ability to compensate grid fluctuations initiated by the customer’s consumption or intermittent electricity production systems such as wind and solar power. Different renewable power generation technologies can be combined in mini-grids to electrify isolated villages and extend existing grid networks. LÄS MER