http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Reconstruction methodology of a Francis runner blade using numerical tools
Giovanni Delgado,Sergio Galván,Francisco Dominguez-Mota,J. C. García,Esteban Valencia 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.3
In a hydraulic turbine, the search of a better energy exchange with the fluid has led to designs of runner blade of geometrical shapes so complex that they are considered as free-form surfaces. Since such blade characteristics are unable to be expressed by analytic functions, its complete and realistic geometrical reconstruction requires an excessive quantity of design parameters. This study proposes a coherent and robust full 3D blade numerical reconstruction methodology in which the geometrical definition of the blade is independent of its design parameters. A quantitative and qualitative fit evaluation shows that the blade surface reconstruction needs an important quantity of discrete data along the spanwise and streamwise direction to achieve a continuous and smooth definition. The results infer that the shape characteristics of damaged and worn blades without an original CAD model could be recovered, making this methodology attractive for industrial and optimization applications.
Numerical analysis of the effects of air on light distribution in a bubble column photobioreactor
McHardy, Christopher,Luzi, Giovanni,Lindenberger, Christoph,Agudo, Jose R.,Delgado, Antonio,Rauh, Cornelia Elsevier 2018 Algal research Vol.31 No.-
<P><B>Abstract</B></P> <P>Light distribution inside photobioreactors (PBR) is a crucial parameter for the determination of growth of phototropic microorganisms and reactor productivity. In order to compute the light propagation inside PBR, scattering due to the presence of microorganisms is often neglected, since it is difficult to measure experimentally and it is not trivial to handle numerically. Moreover, absorption is usually assumed constant, but it is affected by the concentration of microorganisms and the presence of gas bubbles. In the present contribution we study how the flow hydrodynamics and local gas fractions inside a bubble column PBR affect the light distribution. First, we perform numerical simulations of a bubble column flow at different gas superficial velocities. Afterwards, we use instantaneous air volume fractions to calculate the effective scattering and absorption coefficient of the mixture, as well as the effective scattering phase function. Finally, we compute the polychromatic light distribution inside the PBR by means of a Lattice-Boltzmann solver. On the one hand, we find that gas bubbles affect both spatial distribution and magnitude of the light intensity field and their impact increases at higher gas superficial velocity. On the other hand, we also observe that the biomass counteracts these effects already at concentrations less than 1 kg/m<SUP>3</SUP> so that the role of the gas phase on light fields seems to be of minor importance in PBR.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Hybrid numerical simulation of fluid flow and light distribution in a photobioreactor. </LI> <LI> Spatial distribution of gas bubbles affect symmetry and magnitude of the light intensity field. </LI> <LI> Increasing biomass concentration suppresses the effects of the gas phase. </LI> <LI> Role of the gas phase on light fields is of minor importance for cell growth in photobioreactors. </LI> </UL> </P>
Development of Novel Fruit Juice Concentration Process Using Gas Hydrate Technology
Soebiakto LOEKMAN,Timo CLAßEN,Alexander RUDOLPH,Giovanni LUZI,Bernhard GATTERNIG,Christopher MCHARDY,Chae-Gook LEE,Da-Yun PARK,Man-Gi CHO,Cornelia RAUH,Antonio DELGADO 한국생물공학회 2021 한국생물공학회 학술대회 Vol.2021 No.4
Non-thermal food processing has gained interest as it enables the conservation of food properties & sensorial characteristics, such as flavor, color, & mouthfeel. Thermosensitive substances, e.g., vitamin, polyphenol & microbial load are also preserved. Also, the process energy requirement can be drastically reduced. CO2 is an inert gas & can form gas hydrates with water. CO2 is an ideal compound for realizing juices concentration. In the conventional process, juices need to be heated up to 80°C to achieve a degree of concentration between 65–85%, with an energy demand of 180–2,160 kJ/kg H2O. There is a possibility to lose heat-sensitive & volatile components. The freeze concentration process, which acts gentler towards the product, requires an energy demand of 936–1,800 kJ/kg H2O to achieve a concentration of up to 55%. CO2 gas hydrate technology offers a more energy-efficient process with an energy demand of 252–360 kJ/kg H2O. The products can theoretically reach a degree of concentration up to 99%. In this work, the phase equilibrium curve for three fruit juices was established. The results of juice concentration, carried out in two different reactor types, will also be reported.