The development and operational aspects of a signal transfer systemfor use in wind tunnel propeller models

摘要

This paper describes a Signal Transfer System (STS) for use in awind tunnel model propeller. In order to extend the capacity of aconventional mechanical slip ring assembly an electronic multiplexer hasbeen developed, which is located in the rotating part of apropeller-hub. The amplified transducer signals are multiplexed,digitised and transferred over the slip ring assembly located in thepropeller shaft. A demultiplexer unit processes the signals in order tomake them available, in analogue format, for a wind tunnel dataacquisition system. NLR has developed the STS for use in a specific WindTunnel model propeller. Due to space limitations in the model a slipring assembly had to be applied, which had an insufficient number ofslip rings to transfer all signals directly. Two STS have beensuccessfully operated with two model propellers, throughout a number oftests in several European wind tunnels. Special attention has been paidto the operational aspects of the system. A brief overview is presentedfor a future development resulting in a fully contact-less transfersystem, replacing mechanical slip ring assemblies