Simple Two-Dimensional-Nozzle Plume Model for Infrared Analysis
摘要
A simple modeling technique for predicting detailed flow properties in a two-dimensional (2D)-nozzle plume exhausting into quiescent air is presented. The model is constructed by splitting a scaled axisymmetric plume and inserting a rectangular section of constant-property lines in between. A semiempirical scaling factor is derived to account for differences in mixing rates between axisymmetric and nonaxisymmetric plumes. The width of the rectangular section is obtained through conservation of mass. Models have been developed for 2D convergentdivergent nozzles with and without bypass air and for 2D plug nozzles. Comparisons of total-temperature predictions with test data indicate good agreement, especially in the high-temperature core region which is the major contributor to IR signature in the plume.