Fig. 2. LDV probe, flow field orientation and the coordinate system.Figure optionsDownload full-size imageDownload as PowerPoint slide
The settling chamber with the primary and the secondary jet fixtures was attached to a steel table using adjustable threaded rods for fine positioning. Measurements consisted of limited Pitot surveys for the determination of exit velocities, monitoring of pressures and detailed measurements using two-component Laser Doppler Velocimeter. Key features of the LDV system are described below.
2.1. LDV system
The LDV system included on-table optics, data acquisition and KX2-391 units, and the LDV probes. Details of the LDV system used in the current research can be found in Esirgemez et al.  and only key features are discussed.
The laser beams were oriented to measure the U and the V components, separately. While the un-shifted beam and the 50 MHz shifted beams were used to measure the U, the un-shifted beam and the 70 Hz shifted beams were used to measure the V component of the velocity. The beams were aligned such Archaebacteria the axis perpendicular to the bisector of the 0 and 50 MHz shifted beams was oriented along the x axis, while the axis perpendicular to the bisector of the 0 and 70 MHz beams was oriented along the y axis.