Sökning: "turbulence modelling"
Visar resultat 21 - 25 av 118 avhandlingar innehållade orden turbulence modelling.
21. Modelling of Turbulent Flow and Heat Transfer Phenomena in Pipes of District Heating Systems Including Transient Temperature Propagation
Sammanfattning : 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. LÄS MER
22. Numerical Modelling of Diesel Spray Injection, Turbulence Interaction and Combustion
Sammanfattning : 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. LÄS MER
23. Numerical Modelling of Soot Formation in Turbulent Non-Premixed Flames
Sammanfattning : 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. LÄS MER
24. Towards Improved Scale-Resolving Modeling and Simulations of Turbulent Flows
Sammanfattning : 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. LÄS MER
25. Computational fluid-dynamics investigations of vortex generators for flow-separation control
Sammanfattning : 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. LÄS MER