Experimental Stand for Very-Low-Velocity Gas Flow Generation

This article presents an experimental stand for the generation of gas flows with very low velocities. The constant volume air flow was generated in the measurement area with the use of a Mariotte bottle and a water piston (water column in a tank). The air-flow velocity was determined from the change in the height of the water piston with time, which was measured via the difference between the pressure above the water surface and the pressure at the bottom of the water column. The tests were carried out in the mean velocity range of 0.35-66 cm/s. The five different velocities of air flowing out of the measurement pipe, measured with the particle image velocimetry method were compared with the results from the water piston method. The differences did not exceed 7%.