Papers by Amila Wickramasinghe
2022 18th International Conference on Mobility, Sensing and Networking (MSN), Dec 1, 2022
Availability and reliability are emphasized as key factors of wind power generation. Both factors... more Availability and reliability are emphasized as key factors of wind power generation. Both factors are changing as a result of long term climatic changes. The focus of this study was to develop linear wind flow model using WAsP software to identify wind power generation potential and local wind climatic changes in NorthWest coastal region of Sri Lanka. Presently, Ceylon Electricity Board has planned to upgrade the island wide wind potential up to 200 MW. Therefore, it is an important aspect to consider wind climate changes in implementing and operating the wind power plants. Optimum energy production by a wind farm always depends on local wind, properties of turbine site and wind farm layout. Changes in global wind patterns due to various climatic conditions can be identified as a substantial phenomenon because its impacts on wind power generation. This study shows how to monitor the change in power generation of Seguwantivu wind farm by extracting available local wind data in same region. WAsP is a PC program for the prediction of wind climates and power productions from wind turbines and wind farms. WAsP is developed at Risø National Laboratory, Denmark.
Imprensa da Universidade de Coimbra eBooks, 2022
The mechanisms of wildfire attack on structures are classified into direct flame contact, radiant... more The mechanisms of wildfire attack on structures are classified into direct flame contact, radiant heat, firebrand attack and a combination of two or all of them. Arguably, airborne firebrands play a vital role as one of the main causes of structure ignition and fire propagation by forming spot fires far from the fire front. Firebrand flux (the number of firebrands landed on a unit area per unit time) and the heat load are important parameters to calculate the wildfire risk on structures. Australian Building Standard AS3959 is developed based on radiation heat flux and it does not quantify the effects of firebrand flux on structures to assess the wildfire risk completely. To improve the assessment of the Bushfire Attack Level (BAL) in AS3959, there is a need for the quantification of firebrand flux at different scales of wildfires. Lacking information about firebrand generation from various vegetation species under different environmental conditions creates a gap to estimate the firebrand flux accurately. In this study, we aim to use a physics-based model to quantify the firebrand generation rate of Eucalyptus dominant forest vegetation at different severities of wildfires expressed by the Fire danger indices (FDI) of 100, 80, and 50. The wind speed was chosen while keeping the temperature, relative humidity, and drought factor as constants to obtain the focused FDIs. A 40 m height Eucalyptus forest was modelled with 25 t/ha understorey and 10 t/ha canopy fuel loads as per AS3959 forest vegetation classification. The forest fires were prescribed with the intensities of 53.4, 43.1, and 27 MW/m with 100 m length to replicate the fire events explained by FDIs. The depth of the fireline was approximated according to the fire residence time and the spread rate. The firebrand size, shape, and quantity were taken from our previous firebrand generation study (Wickramasinghe et al. 2022) and the particles were injected randomly through the forest volume which is engulfed by the fire. The distances between the modelled structure that follows an Australian standard house design and the vegetation were maintained according to the BALs. We obtained the radiative heat flux on the houses close to the algorithm provided in AS3959 for each BAL. In this study, both firebrand and heat flux were quantified at strategic locations of the house. We find a logarithmic relationship exists between firebrand flux and radiative heat flux in the range of R2 0.96 to 0.99. Hence, for a certain BAL, the firebrand flux increases with the FDI similar to radiative heat flux. Results from this study can be used to quantify the firebrand flux on various house patterns from different vegetation fires, which may improve the design standards and construction requirements of buildings to mitigate the vulnerability of houses at the wildland-urban interface (WUI).
Fire Safety Journal
Firebrands play a vital role in the propagation of fire by starting new fires called spotfires, a... more Firebrands play a vital role in the propagation of fire by starting new fires called spotfires, ahead of the fire front during wildfire progression. Firebrands are a harbinger of damage to infrastructure; their effects particularly pose a threat to people living within the wildland-urban-interface, they can hamper the suppression of wildfire and block evacuation routes for communities and emergency services. Short-range firebrands which travel along with the wind, with little or no lofting, are particularly crucial in increasing fire front propagation and damaging structures situated close to the wildland-urban interface. In the Daylesford fire of 1962 in Australia, massive short-range spotting (the process of spot fire ignition and merging of spots caused by firebrands) occurred in the eucalyptus forest and increased the rate of fire spread by roughly three times more than that computed using an operational fire model. Similarly, long-range firebrands can be transported by the fire plume and ambient wind and can ignite new fire up to 30–40 km from the source of fire as observed in the 2009 Black Saturday fire, Australia. A large amount of experimental research has been conducted to quantify the effects of firebrands, to develop empirical models and to benchmark results for Computational Fluid Dynamic (CFD) based fire model validations. In recent years, some CFD models have been used mainly for their validations. These studies have been reviewed here. To perform useful parametric studies of firebrand transport using CFD models including further development of CFD models, more targeted studies need to be conducted.
Fire, 2022
Firebrand spotting is a potential threat to people and infrastructure, which is difficult to pred... more Firebrand spotting is a potential threat to people and infrastructure, which is difficult to predict and becomes more significant when the size of a fire and intensity increases. To conduct realistic physics-based modeling with firebrand transport, the firebrand generation data such as numbers, size, and shape of the firebrands are needed. Broadly, the firebrand generation depends on atmospheric conditions, wind velocity and vegetation species. However, there is no experimental study that has considered all these factors although they are available separately in some experimental studies. Moreover, the experimental studies have firebrand collection data, not generation data. In this study, we have conducted a series of physics-based simulations on a trial-and-error basis to reproduce the experimental collection data, which is called an inverse analysis. Once the generation data was determined from the simulation, we applied the interpolation technique to calibrate the effects of win...
and the Bushfire and Natural Hazards CRC advise that the information contained in this publicatio... more and the Bushfire and Natural Hazards CRC advise that the information contained in this publication comprises general statements based on scientific research. The reader is advised and needs to be aware that such information may be incomplete or unable to be used in any specific situation. No reliance or actions must therefore be made on that information without seeking prior expert professional, scientific and technical advice. To the extent permitted by law, Victoria University and the Bushfire and Natural Hazards CRC (including its employees and consultants) exclude all liability to any person for any consequences, including but not limited to all losses, damages, costs, expenses and any other compensation, arising directly or indirectly from using this publication (in part or in whole) and any information or material contained in it.
CERN European Organization for Nuclear Research - Zenodo, Jul 13, 2022
The cover photo was taken during Shangri-La village fire of China southwest region in 2014. The b... more The cover photo was taken during Shangri-La village fire of China southwest region in 2014. The buildings of the burning village are mostly wooden structures, and the fire engines cannot enter due to the inconvenient transportation, which brings great difficulty to fire-fighting. A total of 343 structures were destroyed in this large out door (informal settlement) fire. Photo taken by China News Service
Fire Safety Journal, 2022
Firebrands play a vital role in the propagation of fire by starting new fires called spotfires, a... more Firebrands play a vital role in the propagation of fire by starting new fires called spotfires, ahead of the fire front during wildfire progression. Firebrands are a harbinger of damage to infrastructure; their effects particularly pose a threat to people living within the wildland-urban-interface, they can hamper the suppression of wildfire and block evacuation routes for communities and emergency services. Short-range firebrands which travel along with the wind, with little or no lofting, are particularly crucial in increasing fire front propagation and damaging structures situated close to the wildland-urban interface. In the Daylesford fire of 1962 in Australia, massive short-range spotting (the process of spot fire ignition and merging of spots caused by firebrands) occurred in the eucalyptus forest and increased the rate of fire spread by roughly three times more than that computed using an operational fire model. Similarly, long-range firebrands can be transported by the fire plume and ambient wind and can ignite new fire up to 30–40 km from the source of fire as observed in the 2009 Black Saturday fire, Australia.
A large amount of experimental research has been conducted to quantify the effects of firebrands, to develop empirical models and to benchmark results for Computational Fluid Dynamic (CFD) based fire model validations. In recent years, some CFD models have been used mainly for their validations. These studies have been reviewed here. To perform useful parametric studies of firebrand transport using CFD models including further development of CFD models, more targeted studies need to be conducted.
Availability and reliability are emphasized as key factors of wind power generation. Both factors... more Availability and reliability are emphasized as key factors of wind power generation. Both factors are changing as a result of long term climatic changes. The focus of this study was to develop linear wind flow model using WAsP software to identify wind power generation potential and local wind climatic changes in NorthWest coastal region of Sri Lanka. Presently, Ceylon Electricity Board has planned to upgrade the island wide wind potential up to 200 MW. Therefore, it is an important aspect to consider wind climate changes in implementing and operating the wind power plants. Optimum energy production by a wind farm always depends on local wind, properties of turbine site and wind farm layout. Changes in global wind patterns due to various climatic conditions can be identified as a substantial phenomenon because its impacts on wind power generation. This study shows how to monitor the change in power generation of Seguwantivu wind farm by extracting available local wind data in same region. WAsP is a PC program for the prediction of wind climates and power productions from wind turbines and wind farms. WAsP is developed at Risø National Laboratory, Denmark.
Books by Amila Wickramasinghe
Uploads
Papers by Amila Wickramasinghe
A large amount of experimental research has been conducted to quantify the effects of firebrands, to develop empirical models and to benchmark results for Computational Fluid Dynamic (CFD) based fire model validations. In recent years, some CFD models have been used mainly for their validations. These studies have been reviewed here. To perform useful parametric studies of firebrand transport using CFD models including further development of CFD models, more targeted studies need to be conducted.
Books by Amila Wickramasinghe
A large amount of experimental research has been conducted to quantify the effects of firebrands, to develop empirical models and to benchmark results for Computational Fluid Dynamic (CFD) based fire model validations. In recent years, some CFD models have been used mainly for their validations. These studies have been reviewed here. To perform useful parametric studies of firebrand transport using CFD models including further development of CFD models, more targeted studies need to be conducted.