Search for dissertations about: "jet vortex generators"

Found 4 swedish dissertations containing the words jet vortex generators.

2. 1. Turbulent Boundary Layer Separation and Control

   Author : Ola Lögdberg; P. Henrik Alfredsson; Jens Fransson; Guido Buresti; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Flow control; adverse pressure gradient APG ; flow separation; vortex generators; jet vortex generators; pulsed jet vortex generators; Fluid mechanics; Strömningsmekanik;

   Abstract : Boundary layer separation is an unwanted phenomenon in most technical applications, as for instance on airplane wings, ground vehicles and in internal flow systems. If separation occurs, it causes loss of lift, higher drag and energy losses. It is thus essential to develop methods to eliminate or delay separation. READ MORE

4. 2. Computational fluid-dynamics investigations of vortex generators for flow-separation control

   Author : Florian von Stillfried; Arne Johansson; Stefan Wallin; Jonathan Morrison; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flow-separation control; vane vortex generator; vortex generator jet; zero-pressure-gradient turbulent boundary layer; adverse-pressure-gradient turbulent boundary layer; statistical modelling; turbulence; Reynolds stress- transport model; computational fluid dynamics;

   Abstract : Many flow cases in fluid dynamics face undesirable flow separation due to ad-verse pressure gradients on wall boundaries. This occurs, for example, due togeometrical reasons as in a highly curved turbine-inlet duct or on flow-controlsurfaces such as wing trailing-edge flaps within a certain angle-of-attack range. READ MORE

5. 3. Aerodynamic Design and Optimization of Intermediate Ducts for High By-pass Ratio Jet Engines

   Author : Fredrik Wallin; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Intermediate transition ducts; vortex generators; S-shaped ducts; response surface methodology; source term model; optimization;

   Abstract : Demands on improved efficiency and reduced noise levels cause a strive toward high by-pass ratio commercial aero engines. This results in multi-spool aero engines with small high-pressure ratio cores and large fans. The low-pressure system has a lower rotational speed and a larger radius than the high-pressure core system. READ MORE

6. 4. A Study of Subsonic Turbulent Jets and Their Radiated Sound Using Large-Eddy Simulation

   Author : Niklas Andersson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Two-Point Space-Time Correlations; CAA; Jet Noise; LES; Kirchhoff; Coaxial Jets; Heated Jets; Aeroacoustics;

   Abstract : Stricter noise regulation for near-ground operations has made noise reduction in commercial aircraft a topic of growing interest in the aerospace industry. To meet airworthiness requirements new noise reduction technologies have to be developed and numerical methods for correct assessment of these technologies are desirable. READ MORE