Understanding CONTAM Programs and Simulations

1. Introduction

* The CONTAM program is free software from the National Institute of Standards and Technology (NIST) and is widely used worldwide.

* A design approach that allows individual mathematical expressions for virtually all leakage factors (air volume, pressure, area, loss coefficient, density as variables) to interact with their neighbors and each other, and to predict, for a variety of scenarios, zonal pressure, flow air volume, and contaminant spread, through hundreds to tens of thousands of iterative calculations.


2. Design deliverables

* Fan specification: Fan air volume/wind pressure, duct system size, etc. are usually obtained as a result.

* Airflow/pressure characteristics of each zone and leakage elements: Detailed data such as pressure and flow rate of individual zones and individual leakage elements (walls, floors, doors, ducts, etc.) inside and outside the building are obtained as results.


3. Determinants of reliability of results

* Designers need to have a high level of expertise in flue gas control and programming: knowledge of hydrodynamics/fire engineering, understanding of flue gas control systems, legal restrictions, and know-how to use the Contam program determine the reliability of the simulation results.


4. Advantages

* Design for inter-facility balancing : Simulation is performed under the condition that all facilities that are normally operated during a fire are operated, so it is possible to predict the optimal performance according to the mutual influence of simultaneously operated facilities during a fire. 

* Can replace on-site TAB for worst-case conditions: On-site TAB after design and construction is virtually impossible to 'consider worst-case outdoor conditions' and 'operate/measure all simultaneously operated facilities in case of fire', but CONTAM simulation is a design method that can overcome these limitations of TAB. 

* Worst ambient conditions can be considered: mid-winter, mid-summer, maximum wind speed, etc. can be designed.


5. Disadvantages

* Relatively long and expensive design method : Relatively time-consuming and expensive compared to the numerical calculation method.


6. International usage 

* Europe --> CONTAM simulation must be performed for buildings over 60 m in height

  - EN 12101-13 (2022), 1: "Numerical calculations for buildings less than 60 m high, the same requirements are given for buildings over 60 m high (e.g. Table 1), but additional calculation and verification methods are required. The requirements for these methods and verification are given in Annex D, but the methods are beyond the scope of this document [e.g., additional mathematical analysis and/or computational fluid dynamics (CFD)]."

* USA --> Recommendation to perform CONTAM simulations for large buildings with multiple fire suppression systems 

  - NFPA 92 (2021), A.4.9: "Smoke control systems are often designed independently to operate in response to expected dynamic forces (e.g., buoyancy, stack effects, wind). Once the design is complete, the effects of the smoke control systems on each other should be studied. For example, a smoke zone operating in conjunction with a stairwell pressurization system tends to improve the performance of the stairwell pressurization system. At the same time, it can increase the pressure differential between doors, making it more difficult to open doors to stairwells. For complex systems, it is recommended to analyze them using a computer network model (CONTAM?)."


7. Overall evaluation.

* Design tool for large buildings or buildings with a height of approximately 60 meters or more: the most cost-effective design tool available for predicting the capacity and zonal pressures and differential pressures that are closest to real-world conditions.

* Alternative to on-site TAB for the worst outdoor conditions


8. CONTAM vs CFD

* Capabilities of CONTAM simulation: A tool to analyze the balanced fan specifications and smoke survivability of two or more smoke control systems in a multi-zone building (= modeling the performance of fire control units to meet smoke containment).

* Function of CFD simulation: A tool suitable for simulating the spreading behavior of smoke and other harmful gases within a specific space depending on the location within the space in areas such as large atriums or large parking lots where gas properties such as temperature, pressure, and pollutant concentration are not the same within the zone, and it is not possible to analyze the balancing of equipment in a building with two or more smoke control systems.




* Back to Main Procedures : General COMTAM Simulation Procedure for Pressure differential system(Mainly High-rise building) (contamsmulationlab.blogspot.com)



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