The changes in the flow pattern were determined based on the time histories of velocity fluctuations analysed independently in the most characteristic regions of the measuring section.
A physical and mathematical description of the new solution is presented together with an assessment of pressure losses along the measuring section and results of numerical modelling of the design parameter selection.
The main advantages of the thermal tracer were that the movement of the tracer along the measuring section was more easily visible than it was in the real image videos and that it was possible to measure space-averaged flow velocities instead of only one velocity value, with the salt tracer.
In order to determine the methane content in the biogas, a sample of biogas was taken from the reactor once a week using a separate sampling device at the gas measuring section.
The body structure of the BMRS is organized in two sections (Fig. 2): (1) reaction section (situated on the rear side of the apparatus) containing the six reactors with all accessories and (2) measuring section (situated on the front side of the apparatus) containing the six manometers.
Figure 12 shows axial accelerations of the mounting plate (~1 m below pile head; left) and at the first measuring section (~9 m below pile head; right) for the same blow towards the end of the pile driving in the time (top) and frequency domain (bottom).
