Optical and laser diagnostics : The versatility of Imaging

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. In this thesis, multiple applications of imaging are presented, together with possible data processing routines that are used to obtain qualitative and quantitative information. Intuitive ways of presenting big datasets along with trends and variations in them are shown, for both, time-resolved and single-shot measurements. Efforts to enhance the efficiency of internal combustion engines are discussed and a study on the interaction of spray jets and prevailing combustion in light-duty diesel engines is shown. A thorough optical investigation of methanol combustion in compression ignition engines is presented, along with a characterisation of the injection process and fuel distribution for methanol inside a heavy-duty optical engine. The potential of methanol as a renewable fuel and energy carrier is discussed in a wider perspective, together with demonstrating the benefits of such a propulsion system. In addition, a study of exhaled respiratory particles is presented, in an attempt to characterise the potential for transmission of diseases through the respiratory tract. This consisted of an evaluation of everyday tasks such as talking and singing, which is not commonly found in the literature as most studies are focused on sneezing and coughing. Finally, a novel approach on Background Oriented Schlieren, known as Laser Speckle-based BOS, is presented together with some preliminary results. There is great potential for this technique to be used in combustion engine diagnostics, as it requires minimal optical access to create the pattern and the sensitivity of the setup relies less on the distance of the subject to the background pattern

CEAS/AIAA/ICASE/NASA Langley International Forum on Aeroelasticity and Structural Dynamics 1999

These proceedings represent a collection of the latest advances in aeroelasticity and structural dynamics from the world community. Research in the areas of unsteady aerodynamics and aeroelasticity, structural modeling and optimization, active control and adaptive structures, landing dynamics, certification and qualification, and validation testing are highlighted in the collection of papers. The wide range of results will lead to advances in the prediction and control of the structural response of aircraft and spacecraft

THIESEL 2020.Thermo-and Fluid Dynamic Processes in Direct Injection Engines.8th-11th September

'The THIESEL 2020 Conference on Thermo-and Fluid Dynamic Processes in Direct Injection Engines planned in Valencia (Spain) for 8th to 11th September 2020 has been successfully held in a virtual format, due to the COVID19 pandemic. In spite of the very tough environmental demands, combustion engines will probably remain the main propulsion system in transport for the next 20 to 50 years, at least for as long as alternative solutions cannot provide the flexibility expected by customers of the 21st century. But it needs to adapt to the new times, and so research in combustion engines is nowadays mostly focused on the new challenges posed by hybridization and downsizing. The topics presented in the papers of the conference include traditional ones, such as Injection & Sprays, Combustion, but also Alternative Fuels, as well as papers dedicated specifically to CO2 Reduction and Emissions Abatement.Papers stem from the Academic Research sector as well as from the IndustryXandra Marcelle, M.; Desantes Fernández, JM. (2020). THIESEL 2020.Thermo-and Fluid Dynamic Processes in Direct Injection Engines.8th-11th September. Editorial Universitat Politècnica de València. http://hdl.handle.net/10251/150759EDITORIA

Advances on Mechanics, Design Engineering and Manufacturing III

This open access book gathers contributions presented at the International Joint Conference on Mechanics, Design Engineering and Advanced Manufacturing (JCM 2020), held as a web conference on June 2–4, 2020. It reports on cutting-edge topics in product design and manufacturing, such as industrial methods for integrated product and process design; innovative design; and computer-aided design. Further topics covered include virtual simulation and reverse engineering; additive manufacturing; product manufacturing; engineering methods in medicine and education; representation techniques; and nautical, aeronautics and aerospace design and modeling. The book is organized into four main parts, reflecting the focus and primary themes of the conference. The contributions presented here not only provide researchers, engineers and experts in a range of industrial engineering subfields with extensive information to support their daily work; they are also intended to stimulate new research directions, advanced applications of the methods discussed and future interdisciplinary collaborations

NASA Tech Briefs, April 1993

Topics include: Optoelectronics; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences

THIESEL 2022. Conference on Thermo-and Fluid Dynamics of Clean Propulsion Powerplants

The THIESEL 2022. Conference on Thermo-and Fluid Dynamic Processes in Direct Injection Engines planned in Valencia (Spain) for 8th to 11th September 2020 has been successfully held in a virtual format, due to the COVID19 pandemic. In spite of the very tough environmental demands, combustion engines will probably remain the main propulsion system in transport for the next 20 to 50 years, at least for as long as alternative solutions cannot provide the flexibility expected by customers of the 21st century. But it needs to adapt to the new times, and so research in combustion engines is nowadays mostly focused on the new challenges posed by hybridization and downsizing. The topics presented in the papers of the conference include traditional ones, such as Injection & Sprays, Combustion, but also Alternative Fuels, as well as papers dedicated specifically to CO2 Reduction and Emissions Abatement.Papers stem from the Academic Research sector as well as from the IndustryXandra Marcelle, M.; Payri Marín, R.; Serrano Cruz, JR. (2022). THIESEL 2022. Conference on Thermo-and Fluid Dynamics of Clean Propulsion Powerplants. Editorial Universitat Politècnica de València. https://doi.org/10.4995/Thiesel.2022.632801EDITORIA

Advances on Mechanics, Design Engineering and Manufacturing III

This open access book gathers contributions presented at the International Joint Conference on Mechanics, Design Engineering and Advanced Manufacturing (JCM 2020), held as a web conference on June 2–4, 2020. It reports on cutting-edge topics in product design and manufacturing, such as industrial methods for integrated product and process design; innovative design; and computer-aided design. Further topics covered include virtual simulation and reverse engineering; additive manufacturing; product manufacturing; engineering methods in medicine and education; representation techniques; and nautical, aeronautics and aerospace design and modeling. The book is organized into four main parts, reflecting the focus and primary themes of the conference. The contributions presented here not only provide researchers, engineers and experts in a range of industrial engineering subfields with extensive information to support their daily work; they are also intended to stimulate new research directions, advanced applications of the methods discussed and future interdisciplinary collaborations

NASA Langley Highlights, 1997

Langley's mission is accomplished by performing innovative research relevant to national needs and Agency goals, transferring technology to users in a timely manner, and providing development support to other United States Government Agencies, industry, other NASA Centers, the educational community, and the local community. This report contains highlights of some of the major accomplishments and applications that have been made by Langley researchers and by our university and industry colleagues during the past year. The highlights illustrate the broad range of research and technology activities carried out by NASA Langley Research Center and the contributions of this work toward maintaining United States' leadership in aeronautics and space research

Homogeneous Lean Combustion in Downsized Spark-Ignited Engines

Emissions of greenhouse-gasses and noxious compounds from internal combustion engines propelling personal transportation vehicles is an imminent issue in the society. Therefore, it is vital to find means of reducing these emissions to decrease the impacts of transportation. Despite the current rapid electrification of the light duty vehicle fleet, it is expected that there will still be a substantial share of vehicles, produced and sold, that are propelled either solely or partly by combustion engines in the next decades to come. An advantage of combustion engines is that they consume hydrocarbon fuels, which are energy dense and can be produced from renewable sources enabling elimination of net carbon emissions. These fuels can be distributed using the current infrastructure, allowing for a fast transition into a low-carbon transportation system. The sources of renewables are however limited, and production of renewable fuels requires energy, which is why the fuel efficiency of combustion engines is key.This thesis addresses the need for reduced emissions from personal transportation vehicles by investigating homogeneous lean combustion in downsized spark-ignited engines as a means of improving combustion engine fuel efficiency. Lean combustion offers substantial efficiency improvements to the current already well-developed combustion systems. However, historically, it has been proven difficult to achieve robust lean combustion that achieves both efficiency improvements and sufficiently low emissions of nitrogen oxides. In this thesis, the focus has been to investigate the potentially synergetic combination of high engine loads above 10 bar brake mean effective pressure, a common attribute of downsized engines, and lean combustion. The idea is that lean combustion reduces knocking combustion, a harmful event that limits engine efficiency due to cylinder pressure limitations. Simultaneously, it is hypothesized that higher engine loads will lead to faster and more stable combustion, allowing important reductions in nitrogen oxides.Using engine experiments and simulations, homogeneous lean combustion has been investigated. From the experiments it could be concluded that lean combustion can be sustained at high loads. One of the world’s first two-stage turbochargers designed solely for lean combustion was utilized for this purpose and found to be successful. However, it was discovered that lean combustion does not eliminate knocking combustion completelyKeywords: engine, efficiency, emissions, lean, combustion, nor did high load operation eliminate cyclic dispersion of combustion, which imposes limitations. Using improved in-cylinder charge motion and alternative fuels, these limitations can be mitigated, allowing for stable, efficient, low nitrogen oxide high load lean combustion