Developments in design methods for predicting thermal radiation from flares

Models for the prediction of flame shape and radiation field are presented. A model which represents the flame as a frustum of a cone, radiating as a solid body with uniform surface emissive power is described. Correlations describing the variation of flame shape and surface emissive power under a wide range of ambient and flow conditions are discussed. It is shown that by increasing the gas exit velocity the fraction of heat released as radiation and the levels of received radiation are reduced. Correlations of laboratory data and and experience in the field have shown that flames are fully stable under a much wider range of ambient and flow conditions than indicated in API RP 521.