Rigid Sail Investigation in the Wind Tunnel using
Laser Doppler Anemometry (LDA)
In a recent study YRUK has investigated the flow around a sail set with rigid sails using Laser Doppler Anemometry for differential flow velocity measurements.
Objective of the measurement campaign has been obtaining validation data for subsequent flow simulations. The advantage of using rigid sails is the known flying shape of the sails under wind load. This shape can be used as geometry input to the RANSE flow simulations currently carried out using the OpenFOAM toolbox.
The sails had circular profile shape and the the sheeting and twist angles have been measured while obtaining the flow forces and the LDA measurement data.
LDA measurement is a calibration-less velocity measurement method. It measures velocity components in a small measurement volume. A complete measurement campaign consists of 1000 to 2000 individual velocity vector measurements in a 2-dimensional grid, which has been placed in the wake field of the sails. Beside velocity components LDA measurements predict turbulence intensity in the measurement volume.