This paper reports on velocity, pressure, and correlation measurements in the turbulent wake and the adjacent unsteady potential flow of a circular cylinder. Particular attention is given to the effects that attend oscillation of the cylinder in the plane of the lift force. The study was undertaken for four reasons. First was the need to generalize measurement results on the lift force of an oscillating cylinder placed in a flow [1]. Second was the desire to clarify the fluidelastic nature of such forces. Third was the wish to compare gross features of real and computer generated flows. And fourth was the presumed possibility to create unsteady flow of controlled characteristics by using vibrating cylinders. The data presented here pertain to the velocity field close to the cylinder. Actually the records for locations further downstream suggest that prospects for control of flow characteristics using vibrating bluff cylinders do not look promising beyond, say, 15 dia. Measurements made close to the cylinder permit more definite conclusions. The fluidelastic nature of the flow associated with vortex-induced vibrations of cylinders has been demonstrated conclusively. Various existing notions about this question can now be segregated. Reynolds numbers of up to 105 were attained; this is sufficiently high to give results in the range of practical application. Revealing records about the flow field structure were acquired. They permit many conclusions by mere visual inspection because of the special attention given to the unsteady or potential flow region.

An optimization model that may be used by reservoir system operators to improve daily, real‐time operations and to evolve better long‐term operating guidelines is developed and tested. The four multipurpose reservoirs in the Green River Basin (GRB) of Kentucky are used as a case study. The GRB Operation Optimization Model (GRBOOM) is a linear program constructed to imitate the decision‐ making process that results in actual reservoir release decisions. The model is easily modifiable and very flexible, which allows sensitivity analysis and experimentation with new operating guidelines. This experimentation should permit the operators to evolve improved operating policies. The inputs to the model are data that are readily available, and the outputs may be presented in easily interpreted graphical form.

The planforms of two natural meandering rivers, the Wabash River and the White River in Indiana, were investigated using a variety of statistical techniques. Local curvature series were used as the basic statistical descriptor of the planform.Two groups of factors, (1) geology and soil and (2) flow rate and channel slope, were found to be major factors that control the meander planform. This conclusion was supported by probability distribution as well as by time series analysis studies. A method of moving spectrums was developed for the analysis of nonstationary data that are typical in geomorphology. This method was applied to the curvature series of the White and Wabash rivers. It appears to provide an objective way to describe local statistics of the meander shape.

Vortex-induced vibrations of thin flat plates are studied as a function of trailing edge geometry. In an effort to extend the analysis to a more comprehensive treatment than that provided by the common vortex model, the vibrations are considered as hydroelastic phenomena. An equation of motion is formulated. From a qualitative analysis of this nonlinear equation some expected features of its solution are set forth. A detailed experimental determination is made of the amplitude spectra of various thin plates mounted at zero mean angle of incidence in the test section of a water tunnel and suspended by a torsion spring through their leading edge. The effects of trailing edge geometry and elastic properties of plate support are explored. Data analysis gives interesting confirmation of the formulated equation of motion. The vibration is shown to become self-excited and the degree of two dimensionality of the wake is deduced to be determinative in regard to the severity of the vibration.

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