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The laser velocimeter has been utilized for several years at the Arnold Engineering and Development Center (AEDC) as a flow diagnostics tool. Most applications, following the initial proof-of-concept experiments, have involved relatively complex unknown flow fields in which the more conventional, intrusive techniques had either not been attempted or had yielded unsatisfactory results. A blunt-base nozzle-afterbody base flow study is discussed as a respresentative example of such applications. A wide variety of problems have been encountered during these tests, many of which have proven to be closely related to the size and/or size distribution of the seeding material within the fluid. Resulting measurement uncertainties could often not be conclusively resolved because of the unknown nature of the flow field. The other experiments listed were conducted to provide known aerodynamic conditions for comparison with the velocimeter results.

A combined analytical/experimental program for development of an improved slotted wind-tunnel wall representation is described. The effort is scheduled for completion in 1977. The vortex-lattice technique which is being used as the primary analytical tool for representing both the wind-tunnel and the lifting model is discussed. Comparisons of results obtained to date with available data are presented.

Semiempirical solution and mathematical model for jet efflux induced flow fields of V/STOL aircraft