BLEVE is one of major accidents observed in gas industry causing severe damage to people and environment. Its effects are manifested in three ways: shock wave propagation, fireball radiation and fragments projection. To assess these effects, risk decision-makers often use Quantitative Risk Analysis (QRA). In most cases, QRA data are obtained from empirical correlations. However, these correlations are not very satisfactory because they generally overestimate BLEVE effects and do not take into account geometry effects. In order to overcome the limitations of these empirical approaches, CFD modeling appears as a powerful tool able to provide more accurate data to better realize QRA. In this paper, the objective is to develop a CFD methodology in order to predict BLEVE thermal effects. Numerical simulations are carried out using the CFD code FDS. A sensitivity analysis of numerical models is performed in order to choose the right parameters allowing to model the fireball dynamics. The models retained are based on a single-step combustion using EDC model coupled with a LES turbulence model. Predictions show good agreement in comparison with results issued from three large-scale experiments. Furthermore, a case study on a propane accumulator in an Algerian gas processing unit is carried out.

BLEVE is one of major accidents observed in gas industry causing severe damage to people and environment. Its effects are manifested in three ways: shock wave propagation, fireball radiation and fragments projection. To assess these effects, risk decision-makers often use Quantitative Risk Analysis (QRA). In most cases, QRA data are obtained from empirical correlations. However, these correlations are not very satisfactory because they generally overestimate BLEVE effects and do not take into account geometry effects. In order to overcome the limitations of these empirical approaches, CFD modeling appears as a powerful tool able to provide more accurate data to better realize QRA. In this paper, the objective is to develop a CFD methodology in order to predict BLEVE thermal effects. Numerical simulations are carried out using the CFD code FDS. A sensitivity analysis of numerical models is performed in order to choose the right parameters allowing to model the fireball dynamics. The models retained are based on a single-step combustion using EDC model coupled with a LES turbulence model. Predictions show good agreement in comparison with results issued from three large-scale experiments. Furthermore, a case study on a propane accumulator in an Algerian gas processing unit is carried out.

BLEVE is one of major accidents observed in gas industry causing severe damage to people and environment. Its effects are manifested in three ways: shock wave propagation, fireball radiation and fragments projection. To assess these effects, risk decision-makers often use Quantitative Risk Analysis (QRA). In most cases, QRA data are obtained from empirical correlations. However, these correlations are not very satisfactory because they generally overestimate BLEVE effects and do not take into account geometry effects. In order to overcome the limitations of these empirical approaches, CFD modeling appears as a powerful tool able to provide more accurate data to better realize QRA. In this paper, the objective is to develop a CFD methodology in order to predict BLEVE thermal effects. Numerical simulations are carried out using the CFD code FDS. A sensitivity analysis of numerical models is performed in order to choose the right parameters allowing to model the fireball dynamics. The models retained are based on a single-step combustion using EDC model coupled with a LES turbulence model. Predictions show good agreement in comparison with results issued from three large-scale experiments. Furthermore, a case study on a propane accumulator in an Algerian gas processing unit is carried out.

BLEVE is one of major accidents observed in gas industry causing severe damage to people and environment. Its effects are manifested in three ways: shock wave propagation, fireball radiation and fragments projection. To assess these effects, risk decision-makers often use Quantitative Risk Analysis (QRA). In most cases, QRA data are obtained from empirical correlations. However, these correlations are not very satisfactory because they generally overestimate BLEVE effects and do not take into account geometry effects. In order to overcome the limitations of these empirical approaches, CFD modeling appears as a powerful tool able to provide more accurate data to better realize QRA. In this paper, the objective is to develop a CFD methodology in order to predict BLEVE thermal effects. Numerical simulations are carried out using the CFD code FDS. A sensitivity analysis of numerical models is performed in order to choose the right parameters allowing to model the fireball dynamics. The models retained are based on a single-step combustion using EDC model coupled with a LES turbulence model. Predictions show good agreement in comparison with results issued from three large-scale experiments. Furthermore, a case study on a propane accumulator in an Algerian gas processing unit is carried out.

BLEVE is one of major accidents observed in gas industry causing severe damage to people and environment. Its effects are manifested in three ways: shock wave propagation, fireball radiation and fragments projection. To assess these effects, risk decision-makers often use Quantitative Risk Analysis (QRA). In most cases, QRA data are obtained from empirical correlations. However, these correlations are not very satisfactory because they generally overestimate BLEVE effects and do not take into account geometry effects. In order to overcome the limitations of these empirical approaches, CFD modeling appears as a powerful tool able to provide more accurate data to better realize QRA. In this paper, the objective is to develop a CFD methodology in order to predict BLEVE thermal effects. Numerical simulations are carried out using the CFD code FDS. A sensitivity analysis of numerical models is performed in order to choose the right parameters allowing to model the fireball dynamics. The models retained are based on a single-step combustion using EDC model coupled with a LES turbulence model. Predictions show good agreement in comparison with results issued from three large-scale experiments. Furthermore, a case study on a propane accumulator in an Algerian gas processing unit is carried out.

BLEVE is one of major accidents observed in gas industry causing severe damage to people and environment. Its effects are manifested in three ways: shock wave propagation, fireball radiation and fragments projection. To assess these effects, risk decision-makers often use Quantitative Risk Analysis (QRA). In most cases, QRA data are obtained from empirical correlations. However, these correlations are not very satisfactory because they generally overestimate BLEVE effects and do not take into account geometry effects. In order to overcome the limitations of these empirical approaches, CFD modeling appears as a powerful tool able to provide more accurate data to better realize QRA. In this paper, the objective is to develop a CFD methodology in order to predict BLEVE thermal effects. Numerical simulations are carried out using the CFD code FDS. A sensitivity analysis of numerical models is performed in order to choose the right parameters allowing to model the fireball dynamics. The models retained are based on a single-step combustion using EDC model coupled with a LES turbulence model. Predictions show good agreement in comparison with results issued from three large-scale experiments. Furthermore, a case study on a propane accumulator in an Algerian gas processing unit is carried out.

In this paper, a new optically controlled tunneling field effect transistor (OC-TFET) based on SiGe/Si/Ge hetero-channel is proposed to improve optical commutation speed and reduce power consumption. An exhaustive study of the device switching behavior associated with different hetero-channel structures has been carried out using an accurate numerical simulation. Moreover, a new figure of Merit (FoM) parameter called optical swing factor that describes the phototransistor optical commutation speed is proposed. We demonstrate that the band-to-band tunneling effect can be beneficial for improving the device optical commutation speed. The impact of the Ge mole fraction of the SiGe source region on the device FoMs is investigated. It is found that the optimized design with 40% of Ge content offers the opportunity to overcome the trade-off between ultrafast and very sensitive photoreceiver performance, where it yields 48 mV/dec of optical swing factor and 155 dB of I ON /I OFF ratio. An overall performance comparison between the proposed OC-TFET device and the conventional designs is performed, where the proposed structure ensures high optical detectivity for very low optical powers (sub-1pW) as compared to that of the conventional counterparts. Therefore, the proposed OC-TFET provides the possibility for bridging the gap between improved optical commutation speed and reduced power consumption, which makes it a potential alternative for high-performance inter-chip data communication applications.

In this paper, a new optically controlled tunneling field effect transistor (OC-TFET) based on SiGe/Si/Ge hetero-channel is proposed to improve optical commutation speed and reduce power consumption. An exhaustive study of the device switching behavior associated with different hetero-channel structures has been carried out using an accurate numerical simulation. Moreover, a new figure of Merit (FoM) parameter called optical swing factor that describes the phototransistor optical commutation speed is proposed. We demonstrate that the band-to-band tunneling effect can be beneficial for improving the device optical commutation speed. The impact of the Ge mole fraction of the SiGe source region on the device FoMs is investigated. It is found that the optimized design with 40% of Ge content offers the opportunity to overcome the trade-off between ultrafast and very sensitive photoreceiver performance, where it yields 48 mV/dec of optical swing factor and 155 dB of I ON /I OFF ratio. An overall performance comparison between the proposed OC-TFET device and the conventional designs is performed, where the proposed structure ensures high optical detectivity for very low optical powers (sub-1pW) as compared to that of the conventional counterparts. Therefore, the proposed OC-TFET provides the possibility for bridging the gap between improved optical commutation speed and reduced power consumption, which makes it a potential alternative for high-performance inter-chip data communication applications.

The article introduces the benefits and application features of Silvaco Technology Computer Aided Design‘TCAD’ tool to predict the performance of electrical components and their reliability. In this work, in order to improve the electrical parameters of MOS transistor such as, threshold voltage and flat band voltage, we have simulated Phosphorus and Arsenic diffusion profiles in three dimensions before and after thermal annealing in a highly doped polysilicon film using the simulator Silvaco TCAD based on Pearson type IV models. The model takes into account the distribution of vacancy mechanisms and effects related to high concentrations, such as the formation of clusters to study solid solubility limit. The results have been analyzed and discussed in order to extract depth of doping (Phosphorus and Arsenic) and they have been able to optimize the silicon oxide thickness, to reduce the penetration of doping. Based on earlier studies a study of the effect of solubility on these profiles was performed

The article introduces the benefits and application features of Silvaco Technology Computer Aided Design‘TCAD’ tool to predict the performance of electrical components and their reliability. In this work, in order to improve the electrical parameters of MOS transistor such as, threshold voltage and flat band voltage, we have simulated Phosphorus and Arsenic diffusion profiles in three dimensions before and after thermal annealing in a highly doped polysilicon film using the simulator Silvaco TCAD based on Pearson type IV models. The model takes into account the distribution of vacancy mechanisms and effects related to high concentrations, such as the formation of clusters to study solid solubility limit. The results have been analyzed and discussed in order to extract depth of doping (Phosphorus and Arsenic) and they have been able to optimize the silicon oxide thickness, to reduce the penetration of doping. Based on earlier studies a study of the effect of solubility on these profiles was performed

The article introduces the benefits and application features of Silvaco Technology Computer Aided Design‘TCAD’ tool to predict the performance of electrical components and their reliability. In this work, in order to improve the electrical parameters of MOS transistor such as, threshold voltage and flat band voltage, we have simulated Phosphorus and Arsenic diffusion profiles in three dimensions before and after thermal annealing in a highly doped polysilicon film using the simulator Silvaco TCAD based on Pearson type IV models. The model takes into account the distribution of vacancy mechanisms and effects related to high concentrations, such as the formation of clusters to study solid solubility limit. The results have been analyzed and discussed in order to extract depth of doping (Phosphorus and Arsenic) and they have been able to optimize the silicon oxide thickness, to reduce the penetration of doping. Based on earlier studies a study of the effect of solubility on these profiles was performed