|
|
Sudden release of toxic gas in built-up environment
Chaloupecká, Hana ; Jaňour, Zbyněk (advisor) ; Zelinger, Zdeněk (referee) ; Efthimiou, George (referee)
The dissertation thesis deals with short-term gas releases (puffs) in an urban canopy studied utilizing wind-tunnel modelling. The urban canopy was composed of buildings with pitched roofs organised into closed courtyards. Into it, a ground-level point gas source was placed. The first part of the thesis is focused on specific definitions of puff characteristics. New definitions of puff arrival and departure times are presented. Various definitions of puff arrival time were applied on the same datasets and the results were compared. Moreover, it was studied how slight changes in determination of puff departure time can affect its values and other derived puff characteristics. The second part of the thesis is focused on modelling of probability density functions of puff characteristics with knowledge of sampling positions towards the gas source and mean values of concentrations valid for long-term gas sources. The found equations will be utilized in an operational model. The outputs in the form of the probability density functions of puff characteristics distinguish my model from the usually utilized operational models, in which only the ensemble-averaged puff outline and concentration field can be predicted.
|
|
|
Sudden release of toxic gas in built-up environment
Chaloupecká, Hana ; Jaňour, Zbyněk (advisor) ; Zelinger, Zdeněk (referee) ; Efthimiou, George (referee)
The dissertation thesis deals with short-term gas releases (puffs) in an urban canopy studied utilizing wind-tunnel modelling. The urban canopy was composed of buildings with pitched roofs organised into closed courtyards. Into it, a ground-level point gas source was placed. The first part of the thesis is focused on specific definitions of puff characteristics. New definitions of puff arrival and departure times are presented. Various definitions of puff arrival time were applied on the same datasets and the results were compared. Moreover, it was studied how slight changes in determination of puff departure time can affect its values and other derived puff characteristics. The second part of the thesis is focused on modelling of probability density functions of puff characteristics with knowledge of sampling positions towards the gas source and mean values of concentrations valid for long-term gas sources. The found equations will be utilized in an operational model. The outputs in the form of the probability density functions of puff characteristics distinguish my model from the usually utilized operational models, in which only the ensemble-averaged puff outline and concentration field can be predicted.
|
|
| |
|
|
Core of emergency model for urban canopy & Experiments of gas leakages for rural area
Chaloupecká, Hana ; Jakubcová, Michala ; Kellnerová, Radka ; Jurčáková, Klára
The report consists of two parts.\nThe first part copes with the development of an emergency model core for short-term gas leakages for urban canopy. It is explained a procedure in the development of the model, in which after recording input data describing a gas leakage as an output probability density functions for individual puff characteristics and exposed places are obtained. From the output, one can see for example the most probable puff characteristics, which can occur during an accident as well as extreme cases. This is the biggest difference in comparison with the usually used emergency models, in which only mean puff contours and concentration fields are the output. \nIn the second part, experiments of gas leakages for rural area are described. Fulfilment of similarity criterions in wind-tunnel modelling as well as the experiments themselves and the database development is showed.\n
|
guest ::
