Sökning: "drag reduction"
Visar resultat 21 - 25 av 57 avhandlingar innehållade orden drag reduction.
21. District Heating Substations. Performance, Operation and Design
Sammanfattning : This thesis work is concerned with the efficient layout and operation of substations, i.e. those district heating (DH) system units which connect the network and internal building heating systems, such as radiator heating systems and domestic hot water distribution networks. LÄS MER
22. Limiting processes in anion-exchange membrane fuel cells
Sammanfattning : Fuel cells allow for converting chemical energy stored in hydrogen into electrical energy, with only heat and water as by-products. In a sustainable energy society, hydrogen may play an important role due to its ability to act both as an energy carrier and as a valuable chemical in the process industry. LÄS MER
23. Modeling of aerodynamic particle interaction
Sammanfattning : The purpose of the current study is to investigate the effect of particle-pair interaction for various separation distances and angular positions. The results obtained are used in a particle-laden turbulent jet flows in order to improve the existing Lagrangian Particle Tracking (LPT) models. LÄS MER
24. Numerical study of non-spherical/spherical particles in laminar and turbulent flows
Sammanfattning : The presence of solid rigid particles alters the global transport and rheological properties of the mixture in complex (and often unpredictable) ways. In recent years a few studies have been devoted to investigating the behavior of dense suspensions in the turbulent/inertial regime with the majority of theses analyses limited to mono-disperse rigid neutrally-buoyant spheres. LÄS MER
25. Adjoint-based aerodynamic shape optimization
Sammanfattning : An adjoint system of the Euler equations of gas dynamics is derived in order to solve aerodynamic shape optimization problems with gradient-based methods. The derivation is based on the fully discrete flow model and involves differentiation and transposition of the system of equations obtained by an unstructured and node-centered finite-volume discretization. LÄS MER