Search for dissertations about: "turbulence modelling"

Showing result 21 - 25 of 118 swedish dissertations containing the words turbulence modelling.

2. 21. Modelling of Turbulent Flow and Heat Transfer Phenomena in Pipes of District Heating Systems Including Transient Temperature Propagation

   Author : Irina Gabrielaitiene; Värmeöverföring; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; district heating systems ; Energiforskning; Energy research; turbulence modelling .; modelling temperature dynamics ;

   Abstract : Modern district heating systems, a carbon lean technology, involves dual usage of the energy due to the possibility to redistribute heat derived from numerous sources, such as industrial processes, refuse incineration, geothermal sources and combined heat and power plants. Such heat source flexibility facilitates the optimal usage of energy resources by varying the amount of purchased heat depending on demand, price and availability. READ MORE

4. 22. Numerical Modelling of Diesel Spray Injection, Turbulence Interaction and Combustion

   Author : Fabian Kärrholm Peng; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Atomization; Spray; Flame; Cavitation; Ignition Delay; Lift-off; Combustion; Computational Fluid Dynamics; Numerical Scheme; TVD; Diesel; Turbulence Model;

   Abstract : This thesis covers two main topics. The first is numerical modelling ofcavitating diesel injector flows, focusing on describing suchflows using asingle-phase cavitation model based on a barotropic equation of statetogetherwith a homogenous equilibrium assumption. READ MORE

5. 23. Numerical Modelling of Soot Formation in Turbulent Non-Premixed Flames

   Author : Olga Roditcheva; Strömningsteknik; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Motorer; Motors and propulsion systems; Teknik; Technological sciences; oxidation of soot.; soot; polutant formation; flamelet approach; Combustion; turbulence; framdrivningssystem; Thermal engineering; applied thermodynamics; Termisk teknik; termodynamik;

   Abstract : This thesis describes an extended flamelet approach for modelling of soot formation in turbulent hydrocarbons diffusion flames. Detailed chemical kinetic mechanisms are used to compute species concentrations, temperature, density and soot formation rates as functions of flamelet coordinates in the space of mixture fraction and scalar dissipation rate. READ MORE

6. 24. Towards Improved Scale-Resolving Modeling and Simulations of Turbulent Flows

   Author : Magnus Carlsson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hybrid RANS-LES; Numerical methods; Synthetic Turbulence; Compressible flow; Scale-resolving simu- lation; High-order gradient reconstruction; Turbulence modelling;

   Abstract : Scale-resolving simulations are viewed as powerful means for predicting complex turbulentflows, as often encountered in aeronautical applications. However, since turbulent scalesspan over a considerable range from the smallest Kolmogorov scales to the largest ofequivalence to configuration size, scale-resolving computations are often demandingon computational resources and, furthermore, on the underlying numerical methodsused in the simulations. READ MORE

7. 25. Computational fluid-dynamics investigations of vortex generators for flow-separation control

   Author : Florian von Stillfried; Arne Johansson; Stefan Wallin; Jonathan Morrison; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flow-separation control; vane vortex generator; vortex generator jet; zero-pressure-gradient turbulent boundary layer; adverse-pressure-gradient turbulent boundary layer; statistical modelling; turbulence; Reynolds stress- transport model; computational fluid dynamics;

   Abstract : Many flow cases in fluid dynamics face undesirable flow separation due to ad-verse pressure gradients on wall boundaries. This occurs, for example, due togeometrical reasons as in a highly curved turbine-inlet duct or on flow-controlsurfaces such as wing trailing-edge flaps within a certain angle-of-attack range. READ MORE