364
P. Liu
Fig. 5.22 Instantaneous speed process
the electric current applied. The constant temperature type is more widely
used than the constant electric current type.
(2) Particle Image Velocimetry
The particle image velocimeter is called PIV for short. This is a transient,
multi-point, contactless laser, fluid mechanism velocity measurement technique developed in the late 1970s. In recent decades, it has been continuously
improved and developed. The characteristics of PIV technique are beyond the
limitations of single-point speed measurement technology (such as LDA). It
can record the velocity distribution information at a large number of spatial
points in the same transient state and can provide rich information about flow
field structures and flow characteristics (as shown in Fig. 5.23). The principle
Fig. 5.23 PIV flow field information
P. Liu
Fig. 5.22 Instantaneous speed process
the electric current applied. The constant temperature type is more widely
used than the constant electric current type.
(2) Particle Image Velocimetry
The particle image velocimeter is called PIV for short. This is a transient,
multi-point, contactless laser, fluid mechanism velocity measurement technique developed in the late 1970s. In recent decades, it has been continuously
improved and developed. The characteristics of PIV technique are beyond the
limitations of single-point speed measurement technology (such as LDA). It
can record the velocity distribution information at a large number of spatial
points in the same transient state and can provide rich information about flow
field structures and flow characteristics (as shown in Fig. 5.23). The principle
Fig. 5.23 PIV flow field information