Sökning: "Swirling Flow"

Visar resultat 1 - 5 av 63 avhandlingar innehållade orden Swirling Flow.

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

   Författare :Jelle Kranenbarg; Michel Cervantes; Lisa Prahl Wittberg; Luleå tekniska universitet; []
   Nyckelord :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;

   Sammanfattning : 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. LÄS MER

3. 2. Non-Spherical Particle Interaction in Duct and Jet Flow

   Författare :Ammar Hazim; Matthias Mandø; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Solid-gas flow; turbulence modulation; duct flow; coaxial jets flow; swirl jet flow; active flow control; synthetics jet; biomass powder; non-spherical particles; PIV measurement; Strömningslära; Fluid Mechanics;

   Sammanfattning : Wood waste is the most popular biomass recourse for many nations. Burned wood can, direct or indirect, release one of the greenhouse gases, carbon dioxide. The process can still be seen as a renewable source of energy since replanting of the trees and crops are consuming nearly the same amount of carbon dioxide through photosynthesis. LÄS MER

4. 3. Turbulence-resolving Simulations of Swirling Flows

   Författare :Ardalan Javadi; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Swirling Flow; URANS; Hydropower; Hybrid URANS-LES; SAS; Flow Control; Turbulence Modeling; Vortex Breakdown; DDES; LES;

   Sammanfattning : A series of numerical investigations is undertaken using a wide range of turbulence mod-els including conventional and non-conventional URANS models, hybrid URANS-LESmethods and LES to capture a large variety of physical mechanisms that produce pres-sure pulsations in the swirling flows. The available knowledge about these pulsations,which are usual in hydropower, are still far from complete. LÄS MER

5. 4. Effect of swirling blade on flow pattern in nozzle for up-hill teeming

   Författare :Line Hallgren; Pär Jönsson; Jonas Alexis; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; swirling flow; up-hill teeming; nozzle; casting; fluid flow; modelling; CFD; LDA.; Metallurgical process engineering; Metallurgisk processteknik;

   Sammanfattning : The fluid flow in the mold during up-hill teeming is of great importance for the quality of the cast ingot and therefore the quality of the final steel products. At the early stage of the filling of an up-hill teeming mold, liquid steel enters, with high velocity, from the runner into the mold and the turbulence on the meniscus could lead to entrainment of mold flux. LÄS MER

7. 5. A Study of the Swirling Flow Pattern when Using TurboSwirl in the Casting Process

   Författare :Haitong Bai; Mikael Ersson; Pär Jönsson; Yogeshwar Sahai; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flow pattern; swirling flow; TurboSwirl; CFD; turbulence models; water model; flödesmönster; roterandeflöde; TurboSwirl; CFD; turbulensmodeller; vattenmodell; Metallurgical process science; Metallurgisk processvetenskap;

   Sammanfattning : The use of a swirling flow can provide a more uniform velocity distribution and a calmer filling condition according to previous studies of both ingot and continuous casting processes of steel. However, the existing swirling flow generation methods developed in last decades all have some limitations. LÄS MER