Sökning: "direct numerical simulations DNS"

Visar resultat 16 - 20 av 46 avhandlingar innehållade orden direct numerical simulations DNS.

1. 16. Direct Numerical Simulations of Low Temperature Combustion in IC Engine Related Conditions

   Författare :Fan Zhang; Strömningsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : This thesis deals with direct numerical simulation (DNS) of low temperature combustion in internal combustion engine related conditions. In particular, HCCI (homogeneous charge compression ignition), SACI (spark assisted ho-mogeneous charge compression ignition) and PPC (partially premixed charge combustion) were investigated to gain deeper understanding on the details of the combustion process. LÄS MER

3. 17. Numerical studies of turbulent flames in wall-jet flows

   Författare :Zeinab Pouransari; Arne V. Johansson; Yves D'Angelo; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Turbulence; combustion; direct numerical simulation; wall-jet; heat release effects; mixing scales; non-premixed flame; wall heat transfer; Teknisk mekanik; Engineering Mechanics;

   Sammanfattning : The present thesis deals with the fundamental aspects of turbulent mixing and non-premixed combustion in the wall-jet flow, which has a close resemblance to many industrial applications. Direct numerical simulations (DNS) of turbulent wall-jets with isothermal and exothermic reactions are performed. LÄS MER

4. 18. Direct Numerical Simulation of Turbulence on Heterogenous Computer Systems : Architectures, Algorithms, and Applications

   Författare :Martin Karp; Stefano Markidis; Niclas Jansson; Philipp Schlatter; William Gropp; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High Performance Computing; Turbulence; Computational Fluid Dynamics; Heterogenous Computer Architectures; Högprestandaberäkningar; Turbulens; Numerisk Strömingsmekanik; Heterogena Datorarkitekturer; Datalogi; Computer Science;

   Sammanfattning : Direct numerical simulations (DNS) of turbulence have a virtually unbounded need for computing power. To carry out these simulations, software, computer architectures, and algorithms must operate as efficiently as possible to amortize the large computational cost. LÄS MER

5. 19. 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. 20. 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