[freebeard]

Modern problems ==> Modern solutions

journals.sagepub.com/doi/10.1177/16878132221087852

Aerodynamic drag reduction for a truck model using DBD plasma actuators
Abstract
In this study, the effect of DBD plasma actuator based active flow control for a truck model was investigated. Two different electrode shapes which are linear and comb-shaped plasma actuators, are considered. The two DBD plasma actuators are placed at the leading edge or the trailing edge of the trailer, respectively. First, the drag reduction for the DBD plasma actuators at input voltages varying from 6 to 14 kVpp are compared. At a Reynolds number of 25,000, the maximum drag reduction using three comb-shaped plasma actuators at the trailing edge of the trailer is 8.7%, while the maximum drag reduction of three linear plasma actuators is approximately 6%. Then flow visualization behind the truck is performed. At a Reynolds number of 3500 and an input voltage of 14 kVpp, the results show that three comb-shaped plasma actuators installed at the trailing edge of the trailer produce a significant reduction in the wake region. In addition, the PIV measurement is used to quantize the flow field. It is observed that comb-shaped plasma actuators change the slope of the wake region more significantly than using linear plasma actuators. Therefore, this study shows that the use of DBD plasma actuators qualitatively and quantitatively reduces aerodynamic drag.

www.linkedin.com/pulse/plasma-actuators-extremely-complex-physics-help-semi-pranay-bajjuri

Beware the anarcho-tyranny; They will want to ticket you just like you'd put blue dots in your tail lights.

tps://mechanics.stackexchange.com › questions › 50296 › what-was-the-initial-idea-behind-those-blue-dot-tail-lights-from-the-30s-to
What was the initial idea behind those "Blue Dot" tail lights from the ...
"Blue Dot" tail lights seem to be illegal in most US states nowadays (and probably in most other countries, too), but they still seem very popular in the Hot Rod scene. And you can still buy them as 3rd-party parts, even equipped with LEDs. But I wonder how that fashion started.