Accession Number : AD0874029

Title :   Fluidic Vortex Angular Rate Sensor Concept Investigation for Helicopters and V/STOL Aircraft.

Descriptive Note : Final rept.,

Corporate Author : FRANKLIN INST RESEARCH LABS PHILADELPHIA PA

Personal Author(s) : Wachtell, G. P.

Report Date : APR 1970

Pagination or Media Count : 46

Abstract : An experimental investigation was undertaken to establish the feasibility of sensor concepts for application in helicopter and V/STOL aircraft stability augmentation systems. Theories of various possible rate sensing devices based on rapid vortex flows are presented, with experimental demonstration of the principle of one in which the swirl flow axis lags behind the chamber axis when the chamber is rotated about a line perpendicular to its axis. Two modifications yielded sensitivities less than ultimately desired, by factors on the order of 2000 and 200. Observations on the flow pattern in jets emerging from a pair of concentric vortex chambers showed that the concept of the vortex axis jet angular rate sensor (VAJARS) discussed theoretically in a previous feasibility study would have to overcome problems created by turbulence and flow reversal along the axis. An attempt was made to demonstrate a device of high theoretical sensitivity, in which a cylindrical core supported on an axis perpendicular to the core axis is subjected to a torque due to the pressure gradient generated in an annular passage by Coriolis forces. Theoretical discussions are also given of a gyroscope in which the fluid stream is the rotor, and of the deflection of the jet emerging from a swirl chamber subjected to an angular rate. (Author)

Descriptors :   *FLUIDICS), *HELICOPTERS), (*FLOWMETERS, (*STABILIZATION SYSTEMS, (*VERTICAL TAKEOFF AIRCRAFT, STABILIZATION SYSTEMS), VORTICES, FLOW VISUALIZATION, GYROSCOPES, PRESSURE, FEASIBILITY STUDIES, DETECTORS.

Subject Categories : Helicopters
      V/STOL
      Fluidics and Fluerics

Distribution Statement : APPROVED FOR PUBLIC RELEASE