Steering Entropy Revisited

Drivers aim to maintain their vehicle within a number of individualsituated safety margins. Safety margin violations are characterized by rapid strongcorrective steering. Steering entropy was introduced to quantify drivers’ efforts tomaintain their lateral safety margins. In the original steering entropy, severalcomputational assumptions were made. The objective is to scrutinize andmotivate these choices and exemplify the effects of deviations from these choiceswith data from a driver distraction study. The new optimized algorithm is shownto yield significances where a number of classical metrics fail to find anysignificance. Its sensitivity is attributed to the fact that a number of observedchanges in steering behavior all manifest in a widened steering prediction errordistribution which the algorithm picks up sensitively with its log-based weightingof prediction error outliers and its use of a prediction filter that is maximallysensitive to the spectral characteristics of the baseline data

Method of Estimating the Incompressible-flow Pressure Distribution of Compressor Blade Sections at Design Angle of Attack

A method was devised for estimating the incompressible-flow pressure distribution over compressor blade sections at design angle of attack. The theoretical incremental velocities due to camber and thickness of the section as an isolated airfoil are assumed proportional to the average passage velocity and are modified by empirically determined interference factors. Comparisons were made between estimated and test pressure distributions of NACA 65-series sections for typical conditions. Good agreement was obtained

Effect of Tunnel Configuration and Testing Technique on Cascade Performance

An investigation has been conducted to determine the influence of aspect ratio, boundary-layer control by means of slots and porous surfaces, Reynolds number, and tunnel end-wall condition upon the performance of airfoils in cascades. A representative compressor-blade section (the NACA 65-(12)(10) of aspect ratios of 1, 2, and 4 has been tested at low speeds in cascades with solid and with porous side walls. Two-dimensional flow was established in porous-wall cascades of each of the three aspect ratios tested; the flow was not two-dimensional in any of the solid-wall cascades. Turbine-blade sections of aspect ratio 0.83 were tested in cascades with solid and porous side walls and blade sections of aspect ratio 3.33 were tested in cascades with solid wall. No particular advantage was observed in the use of porous walls for the turbine cascades tested