Search for dissertations about: "LES"

Showing result 21 - 25 of 250 swedish dissertations containing the word LES.

2. 21. CFD Modeling of Combustion in Flexi-Fuel Burners at Gas Turbine Conditions

   Author : Abdallah Abou-Taouk; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; SAS-SST; Global reaction mechanism; CFD; LES; RANS; Combustion; PSR; Chemistry;

   Abstract : The main source of energy in the nearest future will come from fossil fuels. Increasing demands on environmentally friendly energy conversion implies that pollutants, such as CO and NOx, need to be reduced. READ MORE

4. 22. On the modelling of turbulent flow and mixing in stirred reactors

   Author : Johan Revstedt; Strömningsteknik; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; turbulence; CFD; stirred reactors; impeller modelling; Energy research; mixing; LES; Energiforskning;

   Abstract : This thesis concerns the numerical simulations and modelling of the flow structure and scalar transport in stirred reactors. For this Large Eddy Simulations (LES) have been used. The flow situation in a stirred reactor includes several flow phenomena that are not well predicted by "standard" two-equation models, e.g. READ MORE

5. 23. Numerical Simulations of Noise Reduction Devices for Aero Engines

   Author : Haukur Hafsteinsson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Acoustic liner; G3D; CAA; CFD; CD-nozzle; LES;

   Abstract : Increasing air traffic and denser population around airports have led to stricterregulations on aircraft noise. The engine is the main source of noise of jet aircraft.Decreasing jet engine noise can in some cases reduce sonic fatigue andthereby increase the engine lifetime. READ MORE

6. 24. Numerical Computations of Wakes Behind Wind Farms : A tool to study Farm to Farm interaction

   Author : Ola Eriksson; Stefan Ivanell; Anna Rutgersson; Simon-Philippe Breton; Philippe Chatelain; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Wind turbine; Wind power; Wind farm; Wakes; Long distance wakes; Farm-Farm; Farm to farm interaction; Wind farm cluster; Large Eddy simulations; LES; Actuator disc method; ACD; CFD; Ellipsys3D; Prescribed boundary layer; PBL; Forced boundary layer; FBL; Meteorologi; Meteorology;

   Abstract : More and larger wind farms are planned offshore. As the most suitable sites to build are limited these new wind farms will be constructed near to each other in so called wind farm clusters. Behind the wind turbines in these farms there is a disrupted flow of air called a wake that is characterized by reduced wind speed and increased turbulence. READ MORE

7. 25. Numerical Simulations of Flows around Trains and Buses in Cross Winds

   Author : Hassan Hemida; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; winds; Trains and buses aerodynamics; LES; DES;

   Abstract : When cruising in strong winds, ground vehicles can experience strong aerodynamic forces and moments that may increase drag, reduce their stability, generate noise and induce accidents in the case of strong side winds. However, prevention of the unwanted influences of side winds requires that the flow structures around vehicles are fully understood in both the instantaneous and time-averaged flow. READ MORE