## 6 Results and Discussion
This behavior is due to the reflection of the waves inside the chambers, making the oscillatory movement more discontinuous and increasing the piston effect, consequently increasing the pressure and velocity, causing recirculation in the turbine duct, as can be seen in Figure 11, with the detail of one of the chambers and its turbine duct. The interval with values of 0.25 < _Hu_/_Ln_ < 0.50, for the five cases analyzed, presents in all of them its highest pressure values. Figure 11: Device model with water (red) and air (blue) and the turbine duct detail, with air recirculation and its maximum (7.198761 m/s) and minimum (\(-\)0.007744 m/s) velocity. Figure 10: Accumulated pressure in each coupled device. by the compression and decompression of the chamber with a greater vertical path to move shows the growth of the internal pressure in all chambers, directly influencing the hydropneumatic power. Figure 12 shows the highest values of accumulated pressure for each case studied, remembering that for each geometric configuration analyzed, the pressure in each coupled chamber is added, being its total the accumulated pressure. In this figure, it is possible to identify that devices with only one chamber have lower pressure values than the others, and this behavior can be explained by the low accumulated pressure that occurs due to having a single chamber. Note that devices with three chambers have higher pressure values than devices with four chambers. This behavior is due to the more regular piston effect in devices with three chambers coupled. Devices with five coupled chambers have the highest accumulated pressure value, and the cases with the highest performance in all analyzed geometries are also concentrated in the same range of values. It can be noticed that devices with a greater number of coupled chambers present higher pressure, a parameter that directly implies the calculation of the hydropneumatic power, as can be seen in Equation (19). Besides, there is a pattern and tendency to increase pressure with an increase in hydropneumatic chambers. The mass flow rate is another component for the calculation of the hydropneumatic power equation. It directly influences the calculation and, through the airflow that passes through the turbine duct, energy conversion occurs when there is an implanted turbine. Figure 13 shows the behavior of the mass flow rate for five related studies. As well as pressure, the highest performance cases are within the same range of values for the cases analyzed (\(0.25<Hn/Ln<0.50\)). The justification for this conclusion is through the compression and decompression process, which, like pressure, occurs with an increase in the height of the chambers and a decrease in width, keeping the inlet volume fixed. There is a gradual and uniform increase in all cases, with a peak value for the performance indicator at the same point of \(Hn/Ln\) in all analyses. As the ratio increases, that is, the chamber height increases and the length of the chamber decreases, there is a decline in the mass flow rate values. This behavior is justified by the length of the duct in which the  
Figure 12: Pressure from the highest performing cases. device's turbine is located, which remains constant because even with high pressure, the mass flow rate tends to decrease. As in the pressure, after analyzing the RMS of the five geometric configurations, the values with the highest mass flow rate are checked and the development of these values is studied with the increase in the number of coupled chambers, as seen in Figure 14. As the number of coupled chambers increases, the mass flow rate also increases. This phenomenon explains the more significant number of piston effects in the hydropneumatic chambers and the increase in mass flow rate. In all cases, the length and height of the duct would have the same values in the energy conversion turbine. The hydropneumatic power represents an association of the results obtained with the mass flow and pressure, as shown in Equation (19).