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The coupling between an axial compressor in an inlet distortion and downstream compression system components is studied analytically and experimentally. The analysis is based on a nonlinear multisegment parallel compressor model coupled to a calculation procedure for the asymmetric flowfield downstream of the compressor. It is shown that in the presence of circumferentially nonuniform flow (distortion) there can be a strong interaction between the compressor and its overall environment. The response of the compressor to an inlet total pressure distortion can therefore depend not only on the compressor, as has sometimes been assumed, but also on the other components in the compression system. Further, the alteration in the response as a result of the interaction can be either beneficial or detrimental, depending on the nature of the component. Experiments investigating this coupling have been carried out on a three stage compressor. The experiments, which involved operating the compressor with three quite different downstream components, show clearly the differences that can exist in compressor response to distortion due to the compressor-component coupling. The analytical predictions of these effects are found to be in good agreement with the experimental results.

The research reported assessed the ability of a human operator to manually null the residual pointing errors that remain on the output of an automatic target tracker under conditions of data link bandwidth reduction. Three operator performance evaluations were conducted using a hybrid computer simulation of the mini-RPV system. The first study assessed the ability of an operator to null the residual errors using a baseline system design. In the study, 32 combinations of environmental and display factors were examined to determine their impact on pointing accuracy. In no case did the average performance reach the 50 microradian standard deviation criterion. The remaining two studies evaluated candidate modifications to the mini-RPV system which would be expected to improve overall tracking performance. Based on these studies, a modified system was identified which allowed criterion tracking accuracy while yielding a 32-to-1 reduction in the data link bandwidth.

A simple algorithm is described for constructing a maximum packing of cuts directed away from a distinguished vertex, called the root, in a directed graph, each of whose edges has a nonnegative weight, and it is shown that the maximum packing value is equal to the weight of a minimum-weight spanning arborescence directed away from the root.

Some of the main notions and theorems about blocking pairs of polyhedra and antiblocking pairs of polyhedra are described. The two geometric duality theories conform in many respects, but there are certain important differences. Applications to various combinatorial extremum problems are discussed, and some classes of blocking and anti-blocking pairs that have been explicitly determined are mentioned.

Given a linear cost function for lengthening arcs, a technique is shown for maximizing, within a budget, the shortest source—sink path length in a graph. The computation is equivalent to the parametric solution of a minimum cost flow problem.