Microscale CFD Simulations of a Wind Energy Test Site in the Swabian Alps with Mesoscale Based Inflow Data

The current study describes analyses of the WINSENT wind energy test site located in complex terrain in Southern Germany by highly resolved numerical simulations. The resolved atmospheric turbulence is simulated with Delayed Detached Eddy Simulations by the flow solver FLOWer without consideration of the research wind turbines. The mean inflow and wind direction of the analysed time period is provided by precursor simulations of project partners. The simulation model chain consists of three codes with different time scales and resolutions. The model chain provides a data transfer from mesoscale WRF simulations to OpenFOAM. As a next step OpenFOAM provides inflow data in the valley of the terrain site for the present FLOWer simulations, the code with the highest resolution in space and time. The mean velocity field provided by OpenFOAM is superimposed with fluctuations that are based on measurements to obtain the small turbulent scales within the FLOWer simulations, which the previous tools of the model chain can not resolve. Comparisons with the two already installed met masts clarify that the current FLOWer simulations provide an adequate agreement with measured data. The results are verified with the application of a second simulation, in which a homogeneous velocity profile is superimposed with turbulence. Thus, comparisons with measured data showed that the benefit of using the inflow data of this model chain is especially evident near the ground

A GIS-Based Planning Approach for Urban Power and Natural Gas Distribution Grids with Different Heat Pump Scenarios

Next to building insulation, heat pumps driven by electrical compressors (eHPs) or by gas engines (geHPs) can be used to reduce primary energy demand for heating. They come with different investment requirements, operating costs and emissions caused. In addition, they affect both the power and gas grids, which necessitates the assessment of both infrastructures regarding grid expansion planning. To calculate costs and CO2 emissions, 2000 electrical load profiles and 180 different heat demand profiles for single-family homes were simulated and heat pump models were applied. In a case study for a neighborhood energy model, the load profiles were assigned to buildings in an example town using public data on locations, building age and energetic refurbishment variants. In addition, the town’s gas distribution network and low voltage grid were modeled. Power and gas flows were simulated and costs for required grid extensions were calculated for 11% and 16% heat pump penetration. It was found that eHPs have the highest energy costs but will also have the lowest CO2 emissions by 2030 and 2050. For the investigated case, power grid investments of 11,800 euros/year are relatively low compared to gas grid connection costs of 70,400 euros/year. If eHPs and geHPs are combined, a slight reduction of overall costs is possible, but emissions would rise strongly compared to the all-electric case.BMWi, 03ET4020C, Verbundvorhaben: Analyse von Strukturoptionen zur Integration erneuerbarer Energien in Deutschland und Europa unter Berücksichtigung der Versorgungssicherheit, Teilvorhaben: Analyse der Verteilnetzebene (INTEEVER-AVN)BMWi, 03ET4069C, Verbundvorhaben INTEEVER-II: Analyse der Integration erneuerbarer Energien in Deutschland und Europa unter Berücksichtigung der Versorgungssicherheit und dezentraler Flexibilitäte

Dynamic-stall measurements using time-resolved pressure-sensitive paint on double-swept rotor blades

The study presents an optimized pressure-sensitive paint (PSP) measurement system that was applied to investigate unsteady surface pressures on recently developed double-swept rotor blades in the rotor test facility at the German Aerospace Center (DLR) in Göttingen. The measurement system featured an improved version of a double-shutter camera that was designed to reduce image blur in PSP measurements on fast rotating blades. It also comprised DLR's PSP sensor, developed to capture transient flow phenomena (iPSP). Unsteady surface pressures were acquired across the outer 65% of the rotor blade with iPSP and at several radial blade sections by fast-response pressure transducers at blade-tip Mach and Reynolds numbers of M_{tip} = 0.282 - 0.285 and Re_{tip}= 5.84 - 5.95 * 10^5. The unique experimental setup allowed for scanning surface pressures across the entire pitch cycle at a phase resolution of 0.225 deg azimuth for different collective and cyclic-pitch settings. Experimental results of both investigated cyclic-pitch settings are compared in detail to a delayed detached eddy simulation using the flow solver FLOWer and to flow visualizations from unsteady Reynolds-averaged Navier Stokes (URANS) computations with DLR's TAU code. The findings reveal a detailed and yet unseen insight into the pressure footprint of double-swept rotor blades undergoing dynamic stall and allow for deducing "stall maps", where confined areas of stalled flow on the blade are identifiable as a function of the pitch phase

On the quantification of OH*, CH*, and C2* chemiluminescence in flames

Nau P, Krüger J, Lackner A, Letzgus M, Brockhinke A. On the quantification of OH*, CH*, and C2* chemiluminescence in flames. APPLIED PHYSICS B. 2012;107(3):551-559.Absolute concentrations of all important chemiluminescent species, OH-A, CH-A, CH-B, and C-2-d have been measured for the first time in methane-oxygen flames at low pressure. The optical detection system for chemiluminescence measurements has been calibrated with Rayleigh and Raman scattering of a cw laser, with the latter approach yielding superior results. The measured ratio between the concentration of CH-B and CH-A suggests that the electronically excited CH* is formed close to thermal equilibrium. Introduction of different rate constants for reactions leading to CH-A and CH-B were not necessary to explain the experimental results. Results are compared with a recent numerical model. Deviations in profile shape and peak positions are relatively small for stoichiometric flames, but become more pronounced in richer mixtures. Larger discrepancies are observed for the absolute concentrations, depending on the chemiluminescent species and the stoichiometry. In an attempt to find an alternative method for the quantification of chemiluminescent species, MIR-CRDS has been performed around 3.9 mu m. While H2O and OH-X could be measured, the sensitivity was not high enough to detect the low sub-ppb concentration of OH-A-in part due to the limited reflectivity of mirrors in the MIR, in part due to a significant background of hot H2O lines

Measurement and simulation of rotationally-resolved chemiluminescence spectra in flames

Brockhinke A, Krüger J, Heusing M, Letzgus M. Measurement and simulation of rotationally-resolved chemiluminescence spectra in flames. APPLIED PHYSICS B. 2012;107(3):539-549

Impact of the environment on the health: From theory to practice

The Erice 56 Charter titled “Impact of the environment on the health: from theory to practice” was unanimously approved at the end of the 56th course of the “International School of Epidemiology and Preventive Medicine G. D'Alessandro” held from 3rd to November 7, 2019 in Erice – Sicily (Italy) and promoted by the Study Group of “Environment and Health” of the Italian Society of Hygiene, Preventive Medicine and Public Health. The course, that included lectures, open discussions and guided working groups, was aimed to provide a general training on epidemiological and toxicological aspects of the environmental health impact, to be used by public health professionals for risk assessment, without forgetting the risk communications. At the end of the course 12 key points were agreed among teachers and students: they underlined the need of specific training and research, in the perspective of “One Health” and “Global Health”, also facing emerging scientific and methodological issues and focusing on communication towards stakeholders. This Discussion highlight the need to improve knowledge of Health and Environment topic in all sectors of health and environmental prevention and management

Impact of the environment on the health: From theory to practice

The Erice 56 Charter titled "Impact of the environment on the health: from theory to practice" was unanimously approved at the end of the 56th course of the "International School of Epidemiology and Preventive Medicine G. D'Alessandro" held from 3rd to November 7, 2019 in Erice - Sicily (Italy) and promoted by the Study Group of "Environment and Health" of the Italian Society of Hygiene, Preventive Medicine and Public Health. The course, that included lectures, open discussions and guided working groups, was aimed to provide a general training on epidemiological and toxicological aspects of the environmental health impact, to be used by public health professionals for risk assessment, without forgetting the risk communications. At the end of the course 12 key points were agreed among teachers and students: they underlined the need of specific training and research, in the perspective of "One Health" and "Global Health", also facing emerging scientific and methodological issues and focusing on communication towards stakeholders. This Discussion highlight the need to improve knowledge of Health and Environment topic in all sectors of health and environmental prevention and management