Sökning: "high angle of attack"

Visar resultat 1 - 5 av 17 avhandlingar innehållade orden high angle of attack.

1. 1. Model based aircraft design : high angle of attack aerodynamics and weight estimation methods

   Författare :Christopher Jouannet; John Fielding; Linköpings universitet; []
   Nyckelord :TECHNOLOGY; TEKNIKVETENSKAP;

   Sammanfattning : This thesis addresses modelling of high angle of attack aerodynamic characteristics and weight estimation for highly maneuverable aircraft during conceptual design. In order to allow configuration selection with sufficient confidence, especially with unconventional configurations, high angle of attack aerodynamic prediction and weight estimations methods need to be improved. LÄS MER

3. 2. Numerical Simulation of High Reynolds Number Wall Bounded Flow

   Författare :Tobias Persson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; subgrid model; DES; high; validation; LES; numerical simulation; near-wall;

   Sammanfattning : In this thesis, four different numerical methods are used for predictions of high Reynoldsnumber (Re), wall bounded flows; Large Eddy Simulation (LES) with two different subgrid(turbulence) models, the One Equation Eddy Viscosity model (OEEVM) and the MixedModel (MM), Monotone Integrated LES (MILES), Detached Eddy Simulation (DES) andReynolds Averaged Navier Stokes (RANS). The LES calculations are combined with a wallmodel based on the law-of-the-wall and in DES a hybrid RANS/LES method is used forhandling the near wall region. LÄS MER

4. 3. Adaptive Mesh Refinement and Simulations of Unsteady Delta-Wing Aerodynamics

   Författare :Yann Le Moigne; KTH; []
   Nyckelord :delta wing; high angle of attack; vortex; pitching; mesh refinement; UCAV; vortex sensor; tensor ofvelocity gradients;

   Sammanfattning : This thesis deals with Computational Fluid Dynamics (CFD)simulations of the flow around delta wings at high angles ofattack. These triangular wings, mainly used in militaryaircraft designs, experience the formation of two vortices ontheir lee-side at large angles of attack. LÄS MER

5. 4. Computational studies of passive vortex generators for flow control

   Författare :Florian von Stillfried; Arne Johansson; Stefan Wallin; Sinisa Krajnovic; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; passive flow control; vortex generator; statistical modelling; turbulence; separation prevention; flat plate; diffuser; high-lift design; airfoil; Fluid mechanics; Strömningsmekanik;

   Sammanfattning : Many flow cases in fluid dynamics face undesirable flow separation due torising static pressure on wall boundaries. This occurs e.g. due to geometry as ina highly curved turbine inlet duct or e. LÄS MER

7. 5. Large Eddy Simulation of Complex Turbulent Flows

   Författare :Magnus Berglund; Strömningsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Gases; fluid dynamics; plasmas; Computational Fluid Dynamics CFD ; Large Eddy Simulation; Complex Turbulent Flows; plasma; Gaser; fluiddynamik;

   Sammanfattning : This thesis concerns the Large Eddy Simulation methodology and its application to predict complex turbulent flows at high Reynolds numbers, and at times also with high Mach numbers. The meaning of the word ?complex? refers both to the presence of complex flow phenomena and the, often, complex geometry of man-made devices restricting the flow. LÄS MER