LDV Laser Doppler Velocimeter

The fiber-optic laser doppler velocimeter (LDV) is also used to measure particle velocity in gas-solid two-phase flow (Yang et al, 1991 Bai, 1991). Figure 8 shows a schematic diagram of the working principle. The... 

The flow pattern of the vortex in the secondary combustion chamber was measured with a Laser Doppler Velocimeter (LDV). The profile measurements were performed at various feed rates and air settings as well as different hardware configurations. The LDV measured the axial and tangential velocity vectors of the flow in the hot flame simultaneously. 

Left Laser Doppler Velocimeter (LDV) for profile velocity measuring system in the secondary combustion chamber. 

The flow pattern in the secondaiy combustion chamber was measured with a Laser Doppler Velocimeter (LDV). The burner was equipped with a heat resistant glass cover to give the laser diagnostic access to the combustion process. To make the flow patterns visible, magnesia powder particles were added to the primary and secondary... 

Finding the path of the particle lends much information to the flow behavior of gas-solid systems. Very few measurement techniques can deal with the individual particle trajectory and its velocity. Some very important technological questions about particle flow may be made with such measurements. Laser Doppler velocimeters (LDV) are available to provide such experimental data. Numerical simulation offers another path for such analysis. The different aspect about finding the path of the particle is that the basic equation defining such behavior is nonlinear, requiring a numerical solution of the equations. This procedure should not be considered as too much of an obstacle, and one should be able to apply knowledge of numerical analysis and experience to such a problem. The basic equation or definition relates the particle position to its velocity and time as... 

Lasers are power tools in gas-solids flows they can be used in dilute-phase systems to measure the particle velocities. These laser Doppler velocimeters (LDVs) require... 

The phase Doppler Technique is a laser-based interferometric approach for simultaneously measuring particle size and velocity. This laser-based method is similar to the well-known laser Doppler velocimeter (LDV) and can make these measurements non-intrusively and with high accuracy. The Phase Doppler Particle Analyzer (PDPA) has been successful applied to many difilcult two-phase flow environments with spherical particles including gas-turbine and rocket fuel inlection, cavitation and bubble formation, and similar two-phase flows. ... 

The experimental apparatus and conditions are the same as described in Sect. 3.3.2. The velocity components in the axial and horizontal directions are measured with a two channel laser Doppler velocimeter (LDV), Further details of the LDV are given elsewhere [21,23]. 

See also Planar cavity surface-emitting laser (PCSEL) diodes Vertical cavity surface-emitting laser (VCSEL) diodes compound semiconductor-based, 22 179 Laser Doppler velocimetry (LDV), 11 784 Laser Doppler velocimeters, 11 675 Laser-drilled surgical needles, 24 206 Laser dye energy levels, 14 702-703 Laser fabrication techniques, titanium, 24 857... 

Multiple impellers have been mainly restricted to the Rushton turbines, inclined pallet turbines with up or down fluxes, and their combinations [7]. The flux patterns are now measured by the Doppler laser velocimeter (LDV) in systems with a single impeller [8] and double impellers [9]. Figure 17.1 shows the hydrodynamic fluxes of a single impeller with a double lace. It is important to notice that in the steady state, the flux varies between the two patterns periodically, the frequency being linearly dependent on the rotating rate of the impeller [9]. 

---