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Flow dynamics and pollutant transport in street canyons of different roof heights and geometries: a wind tunnel and LES modelling
Kluková, Zuzana ; Jaňour, Zbyněk (advisor) ; Perret, Laurent (referee) ; Carpentieri, Matteo (referee)
Understanding the transfer of pollutants within complex urban areas is of utmost importance, but knowledge about it remains limited. This Thesis aims to investigate the characteristics of pollutant transfer, particularly flow dynamics, in six different street canyons integrated into an idealised built-up area consisting of blocks of buildings with courtyards. The systematic study was conducted to evaluate the impact of the following parameters on the ventilation of the street canyons: roof shape, building height non- uniformity and pollutant source position. Two complementary approaches are used in the study: wind-tunnel measurements and numerical modelling. In addition, a wide range of analytical methods are used, including reduced order methods such as Proper Orthogonal Decomposition (POD) and Oscillation Pattern Decomposition (OPD). It is shown that the OPD method provides valuable insights into the ventilation dynamics of street canoyns. The results demonstrate that all the parameters investigated have a significant impact on the ventilation, with roof shape playing a comparatively smaller role for non-uniform street canyons. All the methods applied have contributed to a better understanding of the observed processes while shedding light on the physical implications of the data decomposition methods by...
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Wind-tunnel modelling & development of emergency software
Chaloupecká, Hana ; Kluková, Zuzana ; Jakubcová, Michala ; Kellnerová, Radka ; Jurčáková, Klára
The report describes the procedure of work on the two-year project TACR TJ01000383.\nIn the year 2018, relations between characteristics of short-term and long-term gas leakages for an urban area were searched utilizing the database COST ES1006. Then, releases of short-term and long-term gases for a rural area were studied. A dimensionless database I. was created from the data.\nIn the year 2019, the dispersion of short-term and long-term gas releases in an industrial area was studied. The measured data were analysed and the dimensionless database II. was created. The databases I. and II. were utilized for the validation of the model. We developed software as the main goal of the project.
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Investigation of flow within naturally ventilated cattle barn: preliminary results from wind-tunnel experiments
Nosek, Štěpán ; Kluková, Zuzana ; Kellnerová, Radka ; Jakubcová, Michala ; Jaňour, Zbyněk
The mean vector (longitudinal and vertical velocity components) and scalar (turbulence intensity) fields within a scale (1:50) model of naturally ventilated cattle barn were qualitatively compared in this study. These qualitative comparisons clearly show the effect of the simulated atmospheric boundary layer (ABL) and the opening configuration on the flow characteristics within the barn. ABL of moderately rough terrain produces higher velocities at both the inlet and the outlet openings and inside the barn than that ABL of very rough terrain. However, the intensity of the turbulence is more dependent on the configuration of the opening. For instance, although ABL was very rough and therefore more turbulent, lower turbulence intensities were observed for that ABL than for the moderately rough ABL in the case of middle openings.
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Analysis and assessment of ensemble simulations of regional climate models in Europe for selected scenarios of greenhouse gases
Kluková, Zuzana ; Halenka, Tomáš (advisor) ; Belda, Michal (referee)
An analysis of the air temperature and precipitation for historical and future experiments of regional climate models from Euro-CORDEX activity is presented. A validation of models was performed for the time period 1989 - 2005 using the comparison of model results with E-OBS dataset which represents real values. For this period results show good agreement for temperature, much worse agreement appears for precipitation where their overestimation is more typical. The future evaluation based on the scenarios of greenhouse gases RCP4.5 and RCP8.5 was investigated for periods 2021 - 2050 and 2071 - 2100 in comparison with the period 1971 - 2000 as reference. For the simulations of the future climate we can notice an approximately linear increase of temperatures which is most significant in the northeast Europe. For precipitation models predict their increase in the north Europe and decrease in the south Europe.
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Analysis of Euro-CORDEX regional climate models results
Kluková, Zuzana ; Halenka, Tomáš (advisor) ; Belda, Michal (referee)
In this submitted barchelor's thesis an analysis of the air temperature and precipitation for regional climate models from Euro-CORDEX activity is performed for time period 1989 - 2008. Models are also compared with E-OBS dataset which represents real values. Specifically, models WRF331C (instituce BCCR), RegCM4-2 (CUNI), RegCM4-2 (DHMZ), WRFV35D (IDL), WRF331F (IPSL+INERIS), RACMO22E (KNMI), HadRM3P (Met Office), RCA4 (SMHI), WRF331G (UCAN), PROMES (UCLM) a CCLM-COSMO (WEGC) with resolution 0,11 and 0,44 degrees were considered for the analysis. The analysis is based on the comparison of annual courses, seasonal maps of model biases and Taylor diagrams. Results show good match of models with E-OBS for temperature, much worse agreement appears for precipitation. Temperatures are lower than E-OBS in winter and both higher and lower in summer. Precipitation is usually overestimated.
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