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stabilization of a flame in the eddy region behind a bluff body in a high velocity gas stream is a process of practical as well as theoretical interest. (A bluff body consists of any immersed object whose downstream shape is blunt enough to create a wake of eddies in the stream behind the object.) The practical interest arises because some high output combustorsê .g., for jet engines-anchor the flame in this manner.A flame so stabilized can be made to spread throughout the entire flammable mixture. Flame stabilization by small scale bluff bodies of various geometries has been studied by several recent investigators, including the work of DeZubay (2) on disks, Haddock ( ) and Scurlock {10) on normal cylinders, Longwell et al. ( 7) on parallel cylinders, gutters, and cones, and Weir et al. {11) on spheres. Each of these investigators proposed an empirical correlation for his own data. However, none of these correlations is of wide applicability and there is not yet available a general theory of flame stabilization behind bluff bodies.Any general theory of stabilization must account for several features that are always observed experimentally.

An experimental study was made of the drop sizes obtained on injecting a liquid into large hot airstreams of sustained high velocity. The liquid, a molten synthetic wax, was injected contrastream or costream through simple cylindrical tubes. Downstream, a traversing probe withdrew a representative sample of the stream, cooled it and froze the droplets. The collected solid particles were analyzed by sedimentation and by sieving. The results were correlated empirically by the dimension less equation m --m" (>+^) ( WPL(TL}J,A\ 1112 »L* 7Mass median diameter (X), air density (PA)? relative velocity (J 7 ), liquid viscosity (/JLL) and mass injection rate (W) were changed over 4-to 25-fold ranges. Surface tension (a L ), liquid density (pi) and air viscosity (/JLA) were not changed significantly.

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