Ahmed Kashef

Investigation of air flow around buildings using computational fluid dynamics techniques

Abstract The developments of the Computational Fluid Dynamics (CFD) method as a powerful tool for prediction of wind environmental conditions around buildings are presented in this study. CFD techniques have been applied in predicting wind flow conditions: around a single building, between two parallel buildings and around a multiple building configuration. Also presented is a limited model validation for those simulated configurations. Finally, the paper presents the application of CFD techniques for a case study in simulating an existing site together with proposed buildings and the local landscape.

FIERAsystem: A Fire Risk Assessment Tool to Evaluate Fire Safety in Industrial Buildings and Large Spaces:

FIERAsystem is a computer model for evaluating fire protection systems in industrial buildings. The model has been developed as a tool to assist fire protection engineers, building officials, fire service personnel and researchers in performing fire safety engineering calculations, and can be used to conduct hazard and risk analyses, as well as to evaluate whether a selected design satisfies established fire safety objectives. While the model is primarily designed for use in warehouses and aircraft hangars, it can be modified for application to other industrial buildings. This paper describes the framework for FIERAsystem, along with its capabilities and flexibility. Individual models used to perform calculations are discussed, particularly those that calculate fire development and life hazard. A hazard analysis of an aircraft hangar is then described in detail, as an example of the types of calculations this model can perform. Methods used by the model to conduct risk assessments are also briefly described.

Investigation of the Performance of Emergency Ventilation Strategies in the Event of Fires in a Road Tunnel — A Case Study

A study has been conducted at the National Research Council of Canada to evaluate the effectiveness of in-place emergency ventilation strategies to control smoke spread in the event of a fire in the Louis-Hippolyte-La Fontaine road tunnel. Some of these strategies date back to the design of the tunnel in 1964. Following a recent fire, the operating instructions have been revised. A scientific-based numerical and experimental evaluation of these operating instructions is the main objective of this paper. The numerical evaluation uses the fire dynamics simulator (FDS) model to investigate smoke ventilation in tunnels. The experimental evaluation is used to provide the necessary initial and boundary conditions for the numerical solutions. A parametric study is performed, using the FDS model, assuming a heat source of 20 MW in the tunnel. Two fire scenarios, deemed to cover the two main situations likely to occur in the tunnel, are simulated. The parameters examined are the capacity of ventilation fans and th...

Post-Flashover Compartment Fire for Different Fire Ventilation Settings in a Medium-Sized Residential Room

A number of fire ventilation scenarios were investigated in order to identify the proper ventilation scheme for conducting design fire tests in a medium-sized residential room of a size of 4.2 m long, 3.8 m wide and 2.4 m high. The ventilation schemes were based on using a window, door, or both with different sizes. The fuel package that was used in all scenarios consisted of a mock-up sofa made of polyurethane foam and two wood cribs underneath it. The selection of this fuel package is supported by fire statistics that many fatal residential fires begin with an item of upholstered furniture. The CFD technique was used to conduct the numerical simulations for eleven ventilation scenarios using the Fire Dynamics Simulator (FDS) version 5. The effect of window and door sizes, and fire load location on the heat release rate, burning rate, temperature during the period of fully-developed fire (post-flashover), and the onset of post-flashover and its duration were investigated.Copyright