Sökning: "J. Gunnar I. Hellström"

Visar resultat 1 - 5 av 9 avhandlingar innehållade orden J. Gunnar I. Hellström.

1. 1. Internal erosion in embankment dams : fluid flow through and deformation of porous media

   Författare :J. Gunnar I. Hellström; Thanasis D. Papathanasiou; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strömningslära; Fluid Mechanics;

   Sammanfattning : A basic understanding of fluid flow through a porous media facilitates a comprehensive understanding of internal erosion in embankment dams. Hence, it is necessary to reveal the detailed seepage flow, the flow-induced forces acting within the porous media and the fluid flow deformation of the porous media. LÄS MER

3. 2. Hydraulic Modelling of Dynamics in Regulated Rivers

   Författare :Anton Burman; J. Gunnar I. Hellström; Knut Alfredsen; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strömningslära; Fluid Mechanics;

   Sammanfattning : The Nordic countries hold a significant portion of the European hydropower production. One advantage of hydropower is its ability to store water in reservoirs in times when the energy demand is low. LÄS MER

4. 3. Field Measurements and Predictions of River Flow, Sediment Transport and Morphological Changes

   Författare :Qiancheng Xie; Staffan Lundström; James Yang; J. Gunnar I. Hellström; Anders G. Andersson; Nils Ruther; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Alluvial river; Sediment transport; Morphological change; Meandering; Confluence-diffluence; River training; Field measurements; Numerical simulations; Physical model tests; Machine learning; Alluvial flod; Sedimenttransport; Morfologisk förändring; Slingrande; Konfluens-diffluens; Flodträning; Fältmätningar; Numeriska simuleringar; Fysiska modellprov; Maskininlärning; Strömningslära; Fluid Mechanics;

   Sammanfattning : In an alluvial lowland river, sediment is transported in the form of suspended and bed loads. The fluvial process is the macroscopic view and long-term consequence of sediment movement. LÄS MER

5. 4. Modelling flow over rough surfaces in hydropower waterways

   Författare :Robin Andersson; Staffan Lundström; J. Gunnar I. Hellström; Patrik Andreasson; Jochen Aberle; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strömningslära; Fluid Mechanics;

   Sammanfattning : .... LÄS MER

7. 5. Laser Based Flow Measurements to Evaluate Hydraulic Conditions for Migrating Fish and Benthic Fauna

   Författare :S M Sayeed Bin Asad; Staffan Lundström; J. Gunnar I. Hellström; Anders G. Andersson; Berhanu Mulu Geberkiden; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fish Migration; Step Cylinder; Shedding; Vortex Street; Shear stress; PIV; benthic fauna; river; stones; Strömningslära; Fluid Mechanics;

   Sammanfattning : Hydropower is one of the main sources for Sweden’s energy, which is clean and renewable. It is a clean energy source because no fuels are burned which does not pollute the air and it is a renewable energy source as it only uses natural water cycle for generating energy. LÄS MER