Sökning: "High speed visualization"
Visar resultat 1 - 5 av 35 avhandlingar innehållade orden High speed visualization.
1. Laser Diagnostic Techniques with Ultra-High Repetition Rate for Studies in Combustion Environments
Sammanfattning : When conducting laser based diagnostics in combustion environments it is often desirable to obtain temporally resolved information. This can be due to several factors such as combustion taking place in a turbulent flow field, flame propagation from a spark plug in an initially quiescent combustible mixture, or rapid, multi-point fuel consumption in a homogeneous charge as a result of compression ignition in an engine cycle. LÄS MER
2. Numerical and Experimental Investigation of Hydrodynamic Mechanisms in Erosive Sheet Cavitation
Sammanfattning : Cavitation erosion is one of the limiting factors in the design of hydraulic machinery as it is associated with the reduction in the operating life-time of a hydraulic machine and a significant increase in maintenance cost. In order to be able to design a hydraulic machine with a low risk of cavitation erosion, understanding the hydrodynamic mechanisms controlling the cavitation erosion is of great importance. LÄS MER
3. Laser Spectroscopic Techniques for Combustion Diagnostics Directed Towards Industrial Applications
Sammanfattning : In the work presented in the thesis, different laser spectroscopic techniques were utilized for measurement of species concentrations, as well as for surface thermometry. Experiments were conducted in various combustion environments, ranging from laboratory burners to truck-sized internal combustion (IC) engines, gas turbine combustors and a full-size aircraft turbofan engine. LÄS MER
4. An Experimental Study on Melt Fragmentation, Oxidation and Steam Explosion during Fuel Coolant Interactions
Sammanfattning : Nordic type boiling water reactors (BWRs) adopt reactor cavity flooding as a severe accident mitigation strategy (SAMS) to achieve core melt fragmentation and long-term cooling of decay heat generating core debris. The qualification of this SAMS needs to address two main severe accident issues: debris bed coolability and steam explosion. LÄS MER
5. Advanced Laser-based Multi-scalar Imaging for Flame Structure Visualization towards a Deepened Understanding of Premixed Turbulent Combustion
Sammanfattning : The work presented in the thesis concerns the developments of laser-based diagnostics and its application to the study of turbulent premixed combustion. The diagnostic developments, mainly concerned with planar laser-induced fluorescence (PLIF), are intended to provide instantaneous visualization of the key species originating from the combustion processes involved in the burning of hydrocarbons and nitrogen-containing fuels under turbulent conditions. LÄS MER