Sökning: "Direct Numerical Simulation DNS"

Visar resultat 21 - 25 av 38 avhandlingar innehållade orden Direct Numerical Simulation DNS.

1. 21. Topology optimization of transitional flows

   Författare :Harrison Nobis; Dan Henningson; Philipp Schlatter; Paolo Luchini; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Direct Numerical Simulation; Topology Optimization; Laminar– Turbulent Transition; Spectral Element Method; Direkt numerisk simulering; topologioptimering; laminär–turbulent omslag; spektralelementmetod; Teknisk mekanik; Engineering Mechanics;

   Sammanfattning : This thesis is concerned with the application of topology optimization in thedesign of structures that control fluids. A framework is developed in the high-order Spectral Element Method (SEM) code Nek5000, extending Nek5000 fromits original capabilities, performing Direct Numerical Simulations (DNS), toperforming density-based topology optimization. LÄS MER

3. 22. Turbulent premixed flames in a model gas turbine combustor: fuel sensitivity and flame dynamics

   Författare :Francesco Pignatelli; Strömningsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fuel flexibility; Premixed turbulent combustion; DNS; Optical diagnostic;

   Sammanfattning : The demand for energy security and reduction of greenhouse gas emissions has led to a surge of interest in the development of high-efficiency and low-emission gas turbine engines that can run on alternative low carbon content fuels, such as hydrogen-enriched fuel and syngas. However, the combustion characteristics of these fuels can significantly alter the flame characteristics and operability range of existing combustors. LÄS MER

4. 23. Laminar and turbulent particle laden flows : a numerical and experimental study

   Författare :Seyed Hamid Tabaeikazerooni; Luca Brandt; Jeanette Hussong; Raffaella Ocone; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Suspension flow; inertial effect; turbulent duct flow; finite-size particles; Immersed Boundary Method IBM ; Astigmatism Particle Tracking Velocimetry APTV ; Engineering Mechanics; Teknisk mekanik;

   Sammanfattning : Particle laden flows are widespread in nature and in industrial applications. Dust storms, geophysical flows, pharmaceutical processes, fluidized beds and blood flow are only a few examples. Both global and local properties of a particle laden flow may alter significantly in comparison to the corresponding single phase flow. LÄS MER

5. 24. Statistical characteristics of two-dimensional and quasigeostrophic turbulence

   Författare :Andreas Vallgren; Erik Lindborg; Johan Nilsson; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; two-dimensional turbulence; decaying turbulence; quasigeostrophic turbulence; direct numerical simulation DNS ; coherent vortices; energy cas- cade; enstrophy cascade; intermittency; massively parallel simulations; Non-linear dynamics; chaos; Icke-linjär dynamik; kaos;

   Sammanfattning : Two codes have been developed and implemented for use on massively parallelsuper computers to simulate two-dimensional and quasigeostrophic turbulence.The codes have been found to scale well with increasing resolution and width ofthe simulations. LÄS MER

7. 25. Dynamic properties of two-dimensional and quasi-geostrophic turbulence

   Författare :Andreas Vallgren; Erik Lindborg; Guido Boffetta; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; two-dimensional turbulence; decaying turbulence; quasi-geostrophic turbulence; direct numerical simulation DNS ; coherent vortices; energy cascade; enstrophy cascade; intermittency; massively parallel simulations; locality iii; Non-linear dynamics; chaos; Icke-linjär dynamik; kaos;

   Sammanfattning : Two codes have been developed and implemented for use on massively parallelsuper computers to simulate two-dimensional and quasi-geostrophic turbulence.The codes have been found to scale well with increasing resolution and width ofthe simulations. LÄS MER