Search for dissertations about: "vortical structures"

Showing result 1 - 5 of 19 swedish dissertations containing the words vortical structures.

2. 1. Numerical investigation of the flow and instabilities at part-load and speed-no-load in an axial turbine

   Author : Jelle Kranenbarg; Michel Cervantes; Lisa Prahl Wittberg; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Speed-no-load; vortical flow structures; flow instabilities; rotating stall; mitigation; independent guide vanes; axial turbine; swirling flow; off design operation; URANS; parametric study; blade clearance; head losses; diffusor; GEKO model; flow separation; hydraulic turbine; Strömningslära; Fluid Mechanics;

   Abstract : Global renewable energy requirements rapidly increase with the transition to a fossil-free society. As a result, intermittent energy resources, such as wind- and solar power, have become increasingly popular. However, their energy production varies over time, both in the short- and long term. READ MORE

4. 2. A new experimental setup for studies on wake flow instability and its control

   Author : Bengt Fallenius; Jens Fransson; Henrik Alfredsson; Christoffer Norberg; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Fluid mechanics; Strömningsmekanik;

   Abstract :  A new experimental setup for studies on wake flow instability and its control, which has been designed and manufactured, is introduced and described. The main body is a dual-sided flat plate with an elliptic leading edge and a blunt trailing edge. READ MORE

5. 3. Interaction of sound waves with a swirl stabilized wood powder flame and their effects on flame characteristics

   Author : Burak Göktepe; Henrik Wiinnika; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Energy Engineering; Energiteknik;

   Abstract : Swirling flows have been widely used for many years in engineering applications such as; chemical and mechanical mixing devices, separation units, spray drying technologies, turbo machinery and combustion systems. In practical combustion applications, swirl motion has been adopted to the incoming reactant flows in order to enhance the mixing of fuel and oxidizer and to improve flame stabilization and establishment, especially in regions of relatively low velocities, by recirculating hot product gas to the incoming reactants. READ MORE

6. 4. Flow characterisation of drainage cannulae and centrifugal pumps used in extracorporeal membrane oxygenation: an experimental investigation

   Author : Federico Rorro; Lisa Prahl Wittberg; Lars Mikael Broman; Louis P. Parker; Fredrik Lundell; Ulrich Steinseifer; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Teknisk mekanik; Engineering Mechanics;

   Abstract : Extracorporeal membrane oxygenation (ECMO) is a life-saving treatment for acute respiratory and/or circulatory failure. Typically driven by a centrifugal pump, blood is drained from the patient via one drainage cannula, oxygenated by a membrane lung and returned to the patient via the return cannula. READ MORE

7. 5. Large Eddy Simulation of Impinging Jets

   Author : Thomas Hällqvist; Laszlo Fuchs; Pierre Sagaut; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Impinging jet; large eddy simulation; heat transfer; vortex formation; circular jet; forcing; inflow conditions; implicit modeling.; Fluid mechanics; Strömningsmekanik;

   Abstract : This thesis deals with Large Eddy Simulation (LES) of impinging air jets. The impinging jet configuration features heated circular jets impinging onto a flat plate. The problem addressed here is of generic nature, with applications in many engineering devices, such as cooling of components in gas turbines, in cars and electronic devices. READ MORE