The quantitative risk assessment methods for thermal failure in targets were studied using fire modeling. To this end, Fire Dynamics Simulator (FDS), as a representative fire model, was used and the probabilities related to thermal damage to an electrical cable were evaluated according to the change in fire area inside a specific compartment. 'The maximum probability of exceeding the damage thresholds' adopted in a conservative point of view and 'the probability of failure' including the time to damage were compared. The probability of failure suggested in the present study could evaluate the quantitative fire risk more realistically, compared to the maximum probability of exceeding the damage thresholds with the assumption that thermal damage occurred the instant the target reached its minimum failure criteria in terms of the surface temperature and heat flux.

This study investigated the effect of the dimensionless light extinction coefficient on soot particles concentration for different combustion conditions of bituminous coal. The combustion pressures and burning temperatures were set between 0.1 MPa and 0.3 MPa, and 550 ℃ to 650 ℃, respectively. The dimensionless light extinction coefficient was experimentally measured and the soot particles concentration was calculated using the full-field extinction method and Abel deconvolution technique. The results of this study showed that the dimensionless light extinction coefficient increased with increasing burning temperature under constant pressure. Further, when the burning temperature was constant, the dimensionless light extinction coefficient also increased. In addition, the soot particles concentration increased as the flame height increased, and changed by about 15% as a function of the dimensionless light extinction coefficient at the same flame height.

The strong upward flow called as “acoustic streaming”, when ultrasonic waves were applied in a medium, occurred near to ultrasonic transducer and enhanced the heat transfer. That is, applying ultrasonic waves in a medium may cause the flow velocity of the medium to increase: an effect known as acoustic streaming promotes heat transfer through convection and affects the thermal boundary layer. So, this study was compared with the pressure variations and enhancement of heat transfer by computational simulations and experiments in acoustic field. For the computational simulations, structural vibration simulator (SVS) programmed with a fortran language and based on a coupled finite element-boundary element method (coupled FE-BEM) was used. The results of this study reveal that the acoustic pressure is higher near two ultrasonic transducers than other points where no ultrasonic transducer was installed. The enhancement trend of heat transfer is similar with the profile of the pressure variations. It is concluded that the pressure variations are related to the enhancement of heat transfer in acoustic field.

The present study was numerically and experimentally investigated on thermal deformation of AC7A and AC4C aluminum alloy used as a casting material for manufacturing automobile tire mold. In this study, temperature distributions of AC7A and AC4C casting material were numerically calculated by finite element analysis (FEA). In order to compare and verify results calculated by numerical analysis, the experiment was carried out on the same condition of numerical analysis. The temperature distribution numerical analysis result revealed that the cooling patterns were predicted almost similar results during cooling process of two casting material. Also, the thermal deformation was calculated from the temperature distribution results. The thermal deformation was closely related to the temperature difference between the surface and inside of the casting.

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