Sökning: "Compressible Flows"

Visar resultat 16 - 20 av 43 avhandlingar innehållade orden Compressible Flows.

1. 16. Acceleration of Compressible Flow Simulations with Edge Using  Implicit Time Stepping

   Författare :Evelyn Otero; Arthur Rizzi; Richard P. Dwight; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Compressible CFD; Convergence Acceleration; Implicit Time-Stepping; LU-SGS; Upwind Type Dissipation; Line-implicit; Ordering; Parallelization; Parameters; Multigrid;

   Sammanfattning : Computational fluid dynamics (CFD) is a significant tool routinely used indesign and optimization in aerospace industry. Often cases with unsteadyflows must be computed, and the long compute times of standard methods hasmotivated the present work on new implicit methods to replace the standardexplicit schemes. LÄS MER

3. 17. Numerical simulation of viscous compressible flows applied to turbomachinery blade flutter

   Författare :L. D. Gunnar Sidén; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; unsteady; flutter; turbine; aeroengine; turbomachinery; numerical method; oscillating; Navier-Stokes; finite volume; viscious; finite element; turbulent; fan; aeroelastic; vibration; compressor; stall;

   Sammanfattning : .... LÄS MER

4. 18. Adaptive Algorithms and High Order Stabilization for Finite Element Computation of Turbulent Compressible Flow

   Författare :Murtazo Nazarov; Johan Hoffman; Timothy J. Barth; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Compressible flow; adaptivity; finite element method; a posteriori error estimates; Implicit LES; Applied mathematics; Tillämpad matematik; Numerical analysis; Numerisk analys;

   Sammanfattning : This work develops finite element methods with high order stabilization, and robust and efficient adaptive algorithms for Large Eddy Simulation of turbulent compressible flows. The equations are approximated by continuous piecewise linear functions in space, and the time discretization is done in implicit/explicit fashion: the second order Crank-Nicholson method and third/fourth order explicit Runge-Kutta methods. LÄS MER

5. 19. Flow instabilities in centrifugal compressors at low mass flow rate

   Författare :Elias Sundström; Mihai Mihaescu; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Centrifugal compressor; flow instabilities; rotational flows; rotating stall; surge; compressible Large Eddy Simulation; Engineering Mechanics; Teknisk mekanik;

   Sammanfattning : A centrifugal compressor is a mechanical machine with purpose to convert kineticenergy from a rotating impeller wheel into the fluid medium by compressingit. One application involves supplying boost air pressure to downsized internalcombustion engines (ICE). LÄS MER

7. 20. On stability and receptivity of boundary-layer flows

   Författare :Nima Shahriari; Ardeshir Hanifi; Dan S. Henningson; Peter J. Schmid; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; boundary layer receptivity; acoustic receptivity; swept-wing flow; crossflow vortices; roughness element; global stability analysis; direct numerical simulation; plasma actuator; Engineering Mechanics; Teknisk mekanik;

   Sammanfattning : This work is concerned with stability and receptivity analysis as well as studies on control of the laminar-turbulent transition in boundary-layer flows through direct numerical simulations. Various flow configurations are considered to address flow around straight and swept wings. LÄS MER