Sökning: "the Schlieren technique"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden the Schlieren technique.

1. 1. Optical and laser diagnostics : The versatility of Imaging

   Författare :Alexios Matamis; Förbränningsfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; methanol; COMBUSTION; diesel; schlieren; spray; imaging; pilot-injection; high-speed imaging; Fysicumarkivet A:2021:Matamis;

   Sammanfattning : Optical and laser diagnostics is a field where optical techniques are developed that offer remote, non-intrusive measurements in order to characterise a system. Imaging is a big part of this field and the versatility it offers makes it a great tool in the hands of researchers and in practical applications. LÄS MER

3. 2. Theoretical and Experimental Investigations of Nonlinear Flame Instability

   Författare :Li-Zheng Ma; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; nonlinear hydrodynamic instability; flame propagation and stretch effects; shock induced flame instability; tulip flame formation; interface tracking; the Schlieren technique; level set approach;

   Sammanfattning : Flame instability is both important and difficult to understand. Mechanisms of instability are complex, because instability often involves an interaction between several different physical phenomena, such as an unsteady chemical reaction, unsteady flame propagation generating an unsteady flow, acoustic waves or shock waves. LÄS MER

4. 3. Weak Boundary and Interface Procedures for Wave and Flow Problems

   Författare :Qaisar Abbas; Jan Nordström; Peter Eliasson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; weak boundary conditions; multiple penalty; finite difference methods; summation-by-parts; high order scheme; hybrid methods; MUSCL scheme; shocks; stability; energy estimate; steady-state; non-reflecting; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

   Sammanfattning : In this thesis, we have analyzed the accuracy and stability aspects of weak boundary and interface conditions (WBCs) for high order finite difference methods on Summations-By-Parts (SBP) form. The numerical technique has been applied to wave propagation and flow problems. LÄS MER

5. 4. Propagation of weak shock waves in an elliptical cavity

   Författare :Göran Gustafsson; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strömningslära; Fluid Mechanics;

   Sammanfattning : The propagation of weak shock waves in a planar elliptical cavity is studied theoretically and experimentally. The results are of interest in the design of an elliptical high-speed water jet generator operating in a transient fashion with electrically generated shocks in the acoustic regime. LÄS MER

7. 5. Investigation of a prototype industrial gas turbine combustor using alternative gaseous fuels

   Författare :Ivan Sigfrid; Kraftverksteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Combustion; Gas Turbine; Laminar flame speed; Stretch; Lean blowout; Emissions;

   Sammanfattning : In this thesis, the effect of alternative gaseous fuels, with high hydrogen content and lower calorific value, on gas turbine combustion was investigated experimentally. The aim of the investigation was to find operational limitations for an experimental burner and to supply data for validation of computational fluid dynamics (CFD). LÄS MER