Cloud-burning effect

For typical hydrocarbon sprays in air, v and by using B 10 and Pilpf 10, we find that equation (115) becomes (/> > 0.7. Although there are a number of inaccuracies here, for example, associated with the use of equation (3-63), it may be concluded that stoichiometric hydrocarbon sprays in air may be expected to experience at least some cloud-burning effects. Analyses of spray deflagrations with droplet-group burning have not been pursued. 

Literature on theories of collective effects of droplet interactions was cited in Section 3.3.6. An approximate criterion for the occurrence of a cloud-burning mode with diffusion flames surrounding droplet clouds is readily stated. The overall fuel-gas ratio v (where v is the stoichiometric mass ratio and is the equivalence ratio) is (/>v From... 

The literature provides little information on the effects of thermal radiation from flash fires, probably because thermal radiation hazards from burning vapor clouds are considered less significant than possible blast effects. Furthermore, flash combustion of a vapor cloud normally lasts no more than a few tens of seconds. Therefore, the total intercepted radiation by an object near a flash fire is substantially lower than in case of a pool fire. 

In order to compute the thermal radiation effects produced by a burning vapor cloud, it is necessary to know the flame s temperature, size, and dynamics during its propagation through the cloud. Thermal radiation intercepted by an object in the vicinity is determined by the emissive power of the flame (determined by the flame temperature), the flame s emissivity, the view factor, and an atmospheric-attenuation factor. The fundamentals of heat-radiation modeling are described in Section 3.5. 

Current understanding of how particle clouds and sprays bum is still limited, despite numerous studies—both analytical and experimental—of burning droplet arrays. The main consideration in most studies has been the effect of droplet separation on the overall burning rate. It is questionable whether study of simple arrays will yield much insight into the burning of particle clouds or sprays. 

An unprotected person exposed to H vapor will suffer simultaneously from skin burns, eye injury, and irritation of the respiratory tract.20 The acute effects of H depend on the concentration of the gas, the duration of exposure, the ambient temperature, the extent of protection, and the susceptibility of the person.23 Clothing will be contaminated and become a secondary source of poisoning even after a gas cloud has blown away. 

I am just wondering about your statement that aerosols may have an effect on climate only during periods of strong volcanic activity by increasing the albedo. I am no expert in cloud physics, but I am wondering if increased aerosol burnings in the troposphere could affect cloud processes and thereby have an impact on climate. 

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