2002 Fiscal Year Final Research Report Summary
Study on Ventilation Chaos and Safety of Fire Smoke Exhaust System
| Project/Area Number |
13650653
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Architectural environment/equipment
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| Research Institution | Kyoto Institute of Technology |
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Principal Investigator |
NITTA Katsumichi Kyoto Institute of Technology, Department of Architecture and Design. professor, 工芸学部, 教授 (70026342)
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| Project Period (FY) |
2001 – 2002
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| Keywords | Fire Smoke Venting System / Network Model / Ventilation Variety / Non-linear System / Chaos / CFD Analysis / Symmetric Ventilation / Stairwell |
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| Research Abstract |
This survey related to the generation of variety modes in natural ventilation or fire smoke venting system and its effect on the indoor environmental comfortability or fire safety for refugee. The ventilation variety means the possibility of the generation of different ventilation modes such as ventilation rates, flow direction or room temperatures under same physical conditions for identical buildings. Regardless of deterministic physical system, the realization of a certain mode is stochastic process containing Chaos characteristics.
In the study, it was shown that the usual buoyancy ventilation may potentially possess plural solutions or modes due to the non-linear system on condition that the ventilation in a building with multi rooms could be simulated with the (lumped constant closed circuits) network model. The ventilation variety was tested with the CFD analysis to verify that the variety is not particular in the network model but general in physical phenomena.
The neglect of the ventilation variety would not bring the fire safety as the most important matter, and so the detection and counterplan for the unexpected and undesirable ventilation were surveyed using various building types, especially for the symmetrical buildings and multi-story houses with stairwells. From the simulation results, interesting knowledge was gotten that the ventilation for the symmetric building scarcely resulted in the symmetric ventilation modes. The smoke flow in the stairwell could be modeled with a set of simple orifice at each floor and the equivalent flow resistance was identified by the aid of CFD analysis.
In conclusion, the network model for the multi-room ventilation calculation must have the great confidence of success as the technical method for ensuring against risks in fire smoke prediction, as far as the generation of ventilation variety is taken into consideration.
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