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A fully-developed, two-dimensional, incompressible channel flow was used as the calibration standard to investigate a number of configurations of hot-wire and hot-film anemometer probes of the two principal manufacturers.

Some difficulties in synthesizing velocity perturbation fields from two-point space-time correlation measurements are discussed including the non-uniqueness of the representation and the effects of averaging. A phenomenological model of the fluctuating velocities based on damped travelling waves has been derived. This model is based on the physical mechanism of slow speed streak 'break-up', as taken from hydrogen bubble visualization data. The model compares quite well with the two-point space-time correlation of velocity perturbations. Furthermore, the form derived for the space-time velocity correlation function is exactly the same form as the best available empirical fit to the space-time wall pressure data. (Author).

The classical difficulties in synthesizing the velocity fluctuation field from turbulence data are discussed, including the closure problem, consequent non-uniqueness of the representation, and the loss of information due to averaging. In the present work the inverse approach is used, that is, several analytical models of the velocity fluctuation field, suggested by the flow visualization data, are compared with the existing space-time correlation function data. This approach effectively eliminates the closure problem, but due to its inductive nature, causes some difficulties in disclosing the underlying physics. Using the most promising model, the turbulent flow field has been decomposed, by modeling the velocity fluctations as non-deterministic travelling waves with random phase angles. It is found that this phenomenological model correctly represents the observed trends in the narrow band (frequency filtered) correlation function data. Next, the power spectral density function is identified as the appropriate frequency weighting function with which to synthesize the broad band (unfiltered) from the narrow band correlation functions. The functional form of the power spectral density function which agrees with the observed data is taken to be the superposition of a strong, unorganized background turbulence (Markoff noise) and an organized turbulent structure. The derived broad band correlation functions agree very well with a wide range of turbulent correlation function measurements.

An interacting zone method of calculation is developed for predicting stalled turbulent flows which are nominally two-dimensional, incompressible, and steady. The total problem is divided into zones selected such that each can be.