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Different Boundary Conditions For LES Solver PALM 6.0 Used for ABL in Tunnel Experiment
Řezníček, Hynek ; Geletič, Jan ; Bureš, Martin ; Krč, Pavel ; Resler, Jaroslav ; Vrbová, Kateřina ; Trush, Arsenii ; Michálek, Petr ; Beneš, L. ; Sühring, M.
We tried to reproduce results measured in the wind tunnel experiment with a CFD simulation provided by numerical model PALM. A realistic buildings layout from the Prague-Dejvice quarter has been chosen as a testing domain because solid validation campaign for PALM simulation of Atmospheric Boundary Layer (ABL) over this quarter was documented in the past. The question of input data needed for such simulation and capability of the model to capture correctly the inlet profile and its turbulence structure provided by the wind-tunnel is discussed in the study The PALM dynamical core contains a solver for the Navier-Stokes equations. By default, the model uses the Large Eddy Simulation (LES) approach in which the bulk of the turbulent motions is explicitly resolved. It is well validated tool for simulations of the complex air-flow within the real urban canopy and also within its reduced scale provided by wind tunnel experiments. However the computed flow field between the testing buildings did not correspond well to the measured wind velocity in some points. Different setting of the inlet boundary condition was tested but none of them gave completely developed turbulent flow generated by vortex generators and castellated barrier wall place at the entrance of the aerodynamic section of the wind tunnel.
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POMDPs for dynamic troubleshooting
Krč, Pavel ; Vomlelová, Marta (advisor) ; Hric, Jan (referee)
Dynamic troubleshooting is a process of analysing a running system in real time, predicting or detecting possible problems, correcting them and acting so as to avoid them. When realised by a computer in its most generic form it is an optimum decision problem. The framework of partially observable Markov decision processes (POMDPs) is well suited for such problems as it allows modelling the uncertainty of the future evolution of the process as well as the limited knowledge about the current state and enables to presume its own future choices of actions that alter the system or gain knowledge about it. In this work the author provides an introduction to the theory of POMDPs and describes current POMDP solution algorithms with respect to their applicability for dynamic troubleshooting. Further he presents a speci c dynamic troubleshooting problem, solves it using generic POMDP solutions and proposes his own heuristic for it which can be easily generalised to a wider class of POMDP problems. He creates a Python programming language framework for solving POMDPs, implements the mentioned algorithms within it and tests them on the presented problem.
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City simulation software for modeling, planning, and strategic assessment of territorial city units
Svítek, M. ; Přibyl, O. ; Vorel, J. ; Garlík, B. ; Resler, Jaroslav ; Kozhevnikov, S. ; Krč, Pavel ; Geletič, Jan ; Daniel, Milan ; Dostál, R. ; Janča, T. ; Myška, V. ; Aralkina, O. ; Pereira, A. M.
SVÍTEK, M., PŘIBYL, O., VOREL, J., GARLÍK, B., RESLER, J., KOZHEVNIKOV, S., KRČ, P., GELETIČ, J., DANIEL, M., DOSTÁL, R., JANČA, T., MYŠKA, V., ARALKINA, O., PEREIRA, A. M. City simulation software for modeling, planning, and strategic assessment of territorial city units. 1.1. Prague: CTU & ICS CAS, 2021. Technical Report. ABSTRACT: The Smart Resilience City concept is a new vision of a city as a digital platform and eco-system of smart services where agents of people, things, documents, robots, and other entities can directly negotiate with each other on resource demand principals providing the best possible solution. It creates the smart environment making possible self-organization in sustainable or, when needed, resilient way of individuals, groups and the whole system objectives.
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Detailní simulace proudění, teplot a znečištění vzduchu pro oblast Praha-Dejvice
Resler, Jaroslav ; Geletič, Jan ; Krč, Pavel ; Eben, Kryštof
Simulations of Prague quarter Dejvice were performed with newly developed urban climate model PALM-4U based on LES model PALM. The modelling domain has extent 1000 x 800 m and the resolution of the model was 2 m. Two 24 hours episodes were simulated. The summer episode was intended to assess mainly the UHI effects and the winter episode to assess mainly the air quality issues. Two variants were simulated - the current real situation and the scenario with considered new buildings in the area of Victory Square (Vítězné náměstí). Some comments of the ressults are appended at the end of the report.
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Design of the new generation integrated emission model
Resler, Jaroslav ; Juruš, Pavel ; Benešová, N. ; Vlček, O. ; Belda, M. ; Huszár, P. ; Krč, Pavel ; Eben, Kryštof
The only publicly available and widely used tool for emission modelling for CTM is the processor SMOKE (Coats & Carlie, 1996), but its usage is limited by its strong dependence on conditions of USA. A few attempts to adjust SMOKE to other conditions were made in the past - see e.g. works reported in Bieser et al., 2011 or Borge et al., 2008, but the efforts hit the limits of its design. Our goal is to develop an emission processor based on open technologies which will be easy to use for typical usage with CTM in our conditions and which will be flexible and configurable enough to serve specific needs of users in other countries over the world.
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Modelling assessment of scenarios of urban development to air quality and thermal comfort at street level
Resler, Jaroslav ; Krč, Pavel ; Belda, Michal ; Juruš, Pavel ; Benešová, N. ; Vlček, O. ; Damašková, D. ; Eben, Kryštof ; Derbek, P.
A new model for simulations of urban environment USM was developed and integrated into LES model PALM inside the project UrbanAdapt. The model allows simulations of air flow, radiation, air temperature and temperature of materials, air pollution and indices MRT and PET in fine resolution. The surrounding of a crossroad of the streets Komunardu and Delnicka in Praha-Holesovice was chosen as a pilot area in collaboration with IPR Prague. Studied scenarios included changes of housing development as well as assessment of different types of plant canopy and sensitivity studies of the colour of walls, roofs, streets and pavements.
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Development and validation of the new model of thermal conditions of urban environment in fine resolution
Resler, Jaroslav ; Krč, Pavel ; Belda, Michal ; Juruš, Pavel ; Benešová, N. ; Lopata, J. ; Vlček, O. ; Damašková, D. ; Eben, Kryštof ; Derbek, P. ; Maronga, P. ; Kanani-Sühring, F.
The assessment of different scenarios of the city development to air quality and thermal comfort in the areas of street canyons was our main goal inside the project UrbanAdapt. It follows the need for a model which allows to simulate air flows in fine resolution of the order of meter and realistically predict turbulence in the complex terrain of streets and buildings. The LES models comply with such requirements but the review showed that there was no free available LES model which could model the energy exchange in urban environment, i.e. the interaction of energy and air flows including effects of vegetation and different properties of urban surfaces and materials. Thus we decided to extend the existing LES model PALM by a new module USM (Urban Surface Model) which describes the most important energy exchanges in the urban environment. The validation of the model was done against observations obtained by IR camera in the course of heat wave episode in July 2015.
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POMDPs for dynamic troubleshooting
Krč, Pavel ; Hric, Jan (referee) ; Vomlelová, Marta (advisor)
Dynamic troubleshooting is a process of analysing a running system in real time, predicting or detecting possible problems, correcting them and acting so as to avoid them. When realised by a computer in its most generic form it is an optimum decision problem. The framework of partially observable Markov decision processes (POMDPs) is well suited for such problems as it allows modelling the uncertainty of the future evolution of the process as well as the limited knowledge about the current state and enables to presume its own future choices of actions that alter the system or gain knowledge about it. In this work the author provides an introduction to the theory of POMDPs and describes current POMDP solution algorithms with respect to their applicability for dynamic troubleshooting. Further he presents a speci c dynamic troubleshooting problem, solves it using generic POMDP solutions and proposes his own heuristic for it which can be easily generalised to a wider class of POMDP problems. He creates a Python programming language framework for solving POMDPs, implements the mentioned algorithms within it and tests them on the presented problem.
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