Development steps of 2-color laser-induced fluorescence with MDR-enhanced energy transfer for instantaneous planar temperature measurement of micro-droplets and sprays

[EN] A new method for instantaneous measurement of temperature, size and velocity of micro-droplets has been developed. The method is based on the well-known 2-color laser-induced fluorescence (2cLIF) technique, but uses a pulsed laser for 2-dimensional imaging without motion blur and an adjusted dye mixture for suppression of LIFMDRs by utilizing the MDR-enhanced energy transfer effect. This work presents the development steps that are necessary to verify feasibility of pulsed 2D-2cLIF-EET for micro droplet and hollow-cone spray applications.This work was performed as part of the Cluster of Excellence “Tailor-Made Fuels from Biomass”, which is funded by the Excellence Initiative of the German federal and state governments to promote science and research at German universities.Palmer, J.; Reddemann, M.; Kirsch, V.; Kneer, R. (2017). Development steps of 2-color laser-induced fluorescence with MDR-enhanced energy transfer for instantaneous planar temperature measurement of micro-droplets and sprays. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 661-668. https://doi.org/10.4995/ILASS2017.2017.4591OCS66166

Zooming into primary breakup mechanisms of high-pressure automotive sprays

[EN] In-cylinder mixture formation and combustion are highly influenced by primary breakup of injected fuel. Experimentalinvestigation of this phenomenon directly at the outlet of a diesel injector requires a specialized transmitted light microscopy technique combined with a constant-pressure flow microscopy vessel. The method allows verification of the existence of an intact jet core for various states of injection and different fuels. The jet core is dominated by axisymmetric surface waves during the initial injection phase. By quantification of the wavelengths and comparison with existing breakup theories, boundary layer instabilities are identified as origin of surface waves. Boundary layer wavelengths are found to be larger for a higher fuel viscosity. An occasionally appearing non-cylindrical helical jet shape is visible during the injector’s opening and closing phase. The helical jet shape is directly resulting from the nozzle outlet flow. Inner nozzle effects are found to be responsible for generation of the helical structure. A fuel dependence of the helical structure formation and its breakup could not be proved. Results also prove that fuel is exiting the nozzle even after the injector needle is closed, while air is simultaneously moving into the nozzle orifice.This work was performed as part of the Cluster of Excellence “Tailor-Made Fuels from Biomass”, which was funded by the Excellence Initiative of the German federal and state governments to promote science and research at German universities.Kirsch, V.; Reddemann, M.; Palmer, J.; Kneer, R. (2017). Zooming into primary breakup mechanisms of high-pressure automotive sprays. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 224-231. https://doi.org/10.4995/ILASS2017.2017.4603OCS22423

Информационная система учета и анализа деятельности автомойки «VIP»

Объектом исследования является процесс учета и анализа деятельности автомойки "VIP". Цель работы – исследование, проектирование и разработка информационной системы учета и анализа деятельности автомойки "VIP". Процесс исследования состоял в анализе деятельности организации, обзоре аналогов разрабатываемой информационной системы с целью выбора платформы для разработки ИС. В результате была разработана информационная система учета и анализа деятельности автомойки, выполняющая следующие функции: учет информации о клиентах и автомобилях, учет информации об оказываемых услугах, учет графика работ, анализ деятельности автомойки. Среда разработки: технологическая платформа "1С: Предприятие 8". Степень внедрения: не внедрено. Область применения: информационная система применяется на малых предприяThe object of the study is the process of accounting and analysis of the activities of the car wash "VIP". The purpose of the work is to research, design and develop an information system for accounting and analyzing the activities of the VIP car wash. The research process consisted of an analysis of the organization's activities, a review of the analogues of the information system being developed in order to select a platform for the development of IP. As a result, an information system for accounting and analyzing car wash activities was developed, which performs the following functions: accounting for information about customers and cars, accounting for information about services provided, accounting for work schedules, and analyzing car wash activities. Development environment: techno

Viability of coaxial atomization for disintegration of cell solutions in cell spray applications

[EN] Treating Leukemia with intravenous stem cell transplantation represents a well-established therapy technique. For applications, that require high local cell concentrations, transplantation by conventional intravenous injection is less potent, due to cell distribution with blood circulation. Instead, spraying them directly onto the injured or diseased area shows promising results in various applications, e.g. superficial treatment of topographically challenging wounds, in situ seeding of cells on implants, deposition of cells in tubular organs for stem cell therapy. The present work aims for a basic knowledge about viability boundaries for coaxial cell-spray atomization and the reciprocal influence between cells in solution and primary breakup mechanics. A generic modular nozzle is developed, to ensures reproducible boundary conditions. Investigations are conducted regarding primary breakup and relations between resulting droplet size distribution and cell survival. Measurements are performed, utilizing microscopic high-speed visualization with suitable image post processing. Cell viability is analyzed using phase contrast microscopy prior and after atomization. A relation between Rayleigh-Taylor instability wavelength and droplet size distributions by means of Sauter mean diameter (SMD) and cell survival rate (CSR) is suggested. A power law is presented, exclusively dependent on dimensionless measures (λ⊥ ∼ Re−1/2We−1/3 ) which is found to be proportional to SMD and CSR.We gratefully acknowledge financial support from the Excellence Initiative of the German federal state governments (Exploratory Research Space, RWTH Aachen University).Bieber, M.; Menzel, S.; Thiebes, A.; Cornelissen, C.; Jockenhoevel, S.; Kneer, R.; Reddemann, M. (2017). Viability of coaxial atomization for disintegration of cell solutions in cell spray applications. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 521-528. https://doi.org/10.4995/ILASS2017.2017.4609OCS52152

Mikroskopische Analyse des Zerfalls motorischer Sprühstrahlen

The shape of a liquid jet is strongly influenced by primary breakup close to the nozzle. Especially for microscale and highly turbulent engine sprays this atomization process is still hardly understood. One reason for this circumstance is the poor optical accessibility of the phenomenon. Visual examinations are always limited by diffraction effects, motion blur and multiple scattering of light, as atomization results in a very large number of tiny primary liquid structures, moving at high speed. For this reason, spray characterization is often made on the basis of macroscopic parameters.This work also starts with a macroscopic characterization using high-speed visualization. A parameter variation is done based on a wide range of fluids and material properties. Different empirical cone angle correlations are derived and evaluated in an existing analytical spray model. Based on these findings, the atomization close to the nozzle is analyzed in a second step. To meet the requirements for such a study, a novel microscopic method is developed and applied in this work, the so-called “Double Pulsed Transmitted Light Microscopy“. This method allows a visual determination of sizes, shapes and velocities of primary liquid structures with high spatial and temporal resolution for engine-related injection conditions and ambient pressures. The method is combined with the “Laser Correlation Velocimetry“, which allows the measurement of radial profiles of axial velocity. Based on both methods a detailed characterization of inner jet core, film structures, ligaments and droplets is done for atmospheric conditions as well as for engine-related ambient gas densities. These investigations form the basis for an interpretation of the influence of shear effects, damping effects and the outlet conditions on atomization of an engine-relevant jet

Mikroskopische Analyse des Zerfalls motorischer Sprühstrahlen

The shape of a liquid jet is strongly influenced by primary breakup close to the nozzle. Especially for microscale and highly turbulent engine sprays this atomization process is still hardly understood. One reason for this circumstance is the poor optical accessibility of the phenomenon. Visual examinations are always limited by diffraction effects, motion blur and multiple scattering of light, as atomization results in a very large number of tiny primary liquid structures, moving at high speed. For this reason, spray characterization is often made on the basis of macroscopic parameters.This work also starts with a macroscopic characterization using high-speed visualization. A parameter variation is done based on a wide range of fluids and material properties. Different empirical cone angle correlations are derived and evaluated in an existing analytical spray model. Based on these findings, the atomization close to the nozzle is analyzed in a second step. To meet the requirements for such a study, a novel microscopic method is developed and applied in this work, the so-called “Double Pulsed Transmitted Light Microscopy“. This method allows a visual determination of sizes, shapes and velocities of primary liquid structures with high spatial and temporal resolution for engine-related injection conditions and ambient pressures. The method is combined with the “Laser Correlation Velocimetry“, which allows the measurement of radial profiles of axial velocity. Based on both methods a detailed characterization of inner jet core, film structures, ligaments and droplets is done for atmospheric conditions as well as for engine-related ambient gas densities. These investigations form the basis for an interpretation of the influence of shear effects, damping effects and the outlet conditions on atomization of an engine-relevant jet