Laboratório virtual de bombas hidráulicas para aprendizado de hidráulica aplicada ao saneamento

Abstract

The curves that characterize the behavior of a pumping system are usually studied in physical laboratories. However, there are limitations regarding the parameters that are usually varied in such conditions. The use of virtual laboratories can expand the experiments conducted in physical laboratories in such a way that a better understanding of the effect of varying the parameters can occur. Examples of such parameters include length, pipe diameter, pipe material roughness, fluid viscosity, and the height difference between the lower and upper tanks. In this paper, the development of a responsive design virtual laboratory for a pumping system is described. This virtual laboratory can be used on PC computers, tablets, or smartphones due to its responsive graphical user interface. The equations used to simulate the behavior of the laboratory are the conservation equations, considering the equality between the manometric head provided by the pump and the pressure drop observed in the system. To account for pressure drops, the Darcy-Weisbach equations are used, with friction coefficients defined from the Colebrooke-White equations. The conservation equations are then solved numerically using the bisection method. The results are displayed graphically in the virtual laboratory. These results are the pump head, pressure losses, efficiency and driving power. All of them are as a function of the flow rate. The operating point is calculated and presented graphically. The variables are changed using sliders. The laboratory was tested with students of a Civil Engineering course. The results of a survey conducted with these students showed the effectiveness of the laboratory in promoting a greater understanding of the concepts studied. Most of the survey participants stated that they had greater knowledge of the pump curve, the system pressure loss curve, the pump efficiency curve and the pump driving power curve. This showed the usefulness of plotting these quantities as a function of the flow rate. A greater understanding of the influence of parameter variations was also perceived by the analysis of the survey results. In addition, the tests indicate directions for future developments