UAE6 - Wind Tunnel Tests Data - UAE6 - Sequence E - Raw Data

**Overview**

Sequence E: Yaw Releases (P)

This test sequence used a downwind, rigid turbine with a 3.4° cone angle. The wind speeds
ranged from 7 m/s to 17 m/s. Initial yaw angles of ±90° were achieved. The blade tip pitch was
3°. The rotor rotated at 72 RPM. Blade and probe pressure measurements were collected. The
teeter dampers were replaced with rigid links, and these two channels were flagged as not
applicable by setting the measured values in the data file to ?99999.99 Nm. The teeter link load
cell was pre-tensioned to 40,000 N. The turbine was positioned at each specified yaw angle. A 30-
second data set was collected with the yaw brake engaged. These points used a letter for the last
digit beginning with A and proceeding through the alphabet as repeat points were needed. These
points were plotted and compared to ascertain the functionality of the instrumentation. The files
ending in numbers beginning with 0 and increasing with each repetition represent yaw release
points.

Once the fixed-position yaw test was complete, the yaw drive was engaged to hold the turbine.
The yaw brake was released, and the yaw drive was disabled allowing the turbine to yaw freely.
The yaw drive was disabled about 5 seconds into the campaign, and the turbine was allowed to
yaw freely for the rest of the 30-second duration. When the yaw drive is disabled, no torque is
applied to the motor, and the inertia and yawing force of the nacelle and rotor overcomes the
friction and inertia of the yaw gear and motor. The yaw releases were repeated five times at each
condition. Four additional campaigns were collected to determine the turbine?s natural yaw error
by releasing the brake at 0° yaw error. These file names use the E designation, followed by two
digits for wind speed, followed by XXXX, followed by the repetition digit.

**Data Details**

File naming information can be found in the attached Word document "Sequence E Filename Key", copied from the Phase VI Test Report.