Dynamic liquid film measurement with Fourier transform profilometry

The high-speed measurement and reconstruction of dynamic liquid film 3D morphology is very important for the industrial process optimization in energy and power fields. Based on the Fourier transform profilometry, the simulation was performed for both slow and fast varying surfaces. The influencing factors of reconstructive accuracy on object surface morphology such as surface height change rate, environment random noise and fringe frequency were studied. And according to the simulation results, the optimal system parameters were obtained, high-speed 3D structured light measurement system was established and the surface morphology of dynamic liquid film was measured. The experimental results show that, as the liquid film flows downward along the vertical wall surface, the liquid film thickness first increases and then decreases, and the average error of the height direction is 0.1 mm. This work demonstrates that Fourier transform profilometry can be well applied in the high-speed measurement of dynamic liquid film.