A Semi-Automated Wake Survey and Analysis System Applied to Small Models

摘要

A semi-automated wake survey and data analysis system is described. This system was developed to satisfy the modern needs of the propeller specialist, overcoming the shortcomings of the traditional methods. The salient features of this system are electro-mechanical sensing of pressures from a pitot tube probe continuously sweeping in a circular path about the propeller shaft, electronic recording of pressure signals, analog to digital conversion of data and computer analysis yielding velocity vector, harmonic analysis, and velocity and harmonic statistics. Instead of measurements of the wake velocity vector at a small set of discrete points in space, the sweeping probe allows the electronic recording of a continuous spacial sampling of the wake field at any given radius. The high spatial resolution attainable by analog-to-digital sampling makes possible the accurate determination of wake harmonics to high orders. (Author)