Sökning: "värmeflöden"

Hittade 5 avhandlingar innehållade ordet värmeflöden.

  1. 1. Evaporation and Heat-flux Aggregation in Heterogeneous Boreal Landscapes

    Författare :Tony Persson; Sven Halldin; Dimitris Melas; Deliang Chen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Hydrology; land-surface processes; heterogeneity; surface fluxes; soil-water content; high latitudes; snow; lakes; climate; mesoscale model; NOPEX; WINTEX; Hydrologi; Hydrology; Hydrologi;

    Sammanfattning : The boreal forests represent 8 % of all forested areas on the earth and have a significant role in the control of greenhouse gases and an impact on global climate change. The main objective of this thesis is to increase the understanding of how evaporation and heat-flux processes in the boreal forest zone are affecting the regional and global climate. LÄS MER

  3. 2. Experimentella studier av värmeflöden och värmelagring i ett bebott flerbostadshus

    Författare :Lars Stenlund; Gunnar Bäckström; Olov Sandberg; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Energy balance; heat storage; heat flow; night setback; buildings; time constants;

    Sammanfattning : The study is experimentally inclined, with a high target precision for performance measurement. A comprehensive programme of measurements was carried out in a two-storey building, having a massive structure and dating from 1970. Measurements were made continuously during the heating season from a total of about 70 points. LÄS MER

  4. 3. CFD Study of Molten Pool Convection in a Reactor Vessel during a Severe Accident

    Författare :Boshen Bian; Walter Villanueva; Sevostian Bechta; Weimin Ma; Shuisheng He; KTH; []
    Nyckelord :Severe accident; Corium; Natural convection; Turbulence; Scalability; Direct numerical simulation DNS .; Svåra haverier; härdsmälta; naturlig konvektion; turbulens; skalbarhet; direkt numerisk simulering DNS .; Physics; Fysik;

    Sammanfattning : During severe accidents in nuclear reactors, the core and internal structures can melt down and relocate into the reactor pressure vessel (RPV) lower head (LH) forming there a stratified molten corium pool. The pool generally consists of superheated oxidic and metallic liquid layers imposing thermo-mechanical loads on the RPV wall. LÄS MER

  5. 4. High-resolution simulations of two cold palaeo climates in Europe : MIS 3 and LGM

    Författare :Gustav Strandberg; Erik Kjellström; Qiong Zhang; Johan Nilsson; Anders Moberg; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Palaeo climate; climate modelling; proxy data; LGM; MIS 3; meteorologi; Meteorology;

    Sammanfattning : The study of past climate is important because it increases our understanding of how the climate system works. Past climate is often reconstructed by using proxies (that is observations of things that tell something about past climate, for example tree rings, pollen in lake sediments and fossils). LÄS MER

  7. 5. Simulation of historic buildings for enhancement of preservation and energy performance – issues and methods

    Författare :Torun Widström; Folke Björk; Kjartan Gudmundsson; Jesper Arfvidsson; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Building simulation; historic buildings; energy performance; damage risk; mould; thermal bridges; Byggvetenskap; Civil and Architectural Engineering;

    Sammanfattning : Historic buildings are often particularly poorly insulated and difficult to heat, and are also at risk for several reasons. These include potential lack of use due to low thermal comfort leading to low or no profitability, damage risks due to over and under-climatization and risks due to climate change altering the boundary conditions that they were built for. LÄS MER