Coeficientes de descarga de orifícios retangulares em parede delgada vertical curva.

Abstract

The objective of this work was to verify the influences of plate curvature and simultaneous operation of side by side orifices on discharge coefficient of rectangular orifices in vertical thin plate. The influence of plate curvature was evaluated in 40 x 80 mm rectangular orifices perforated in four PVC pipes, one with square section, and the other ones with cylindrical sections and external diameter of 250, 350 and 450 mm. The influence of simultaneous operation was evaluated in a 250 mm of external diameter pipe, with eight 40 x 80 mm rectangular orifices around it. Increasing 0.32 rad (18.3°) in angle a between orifice axis and its plate, the discharge coefficient decreased 3.5%. Otherwise, increasing number of orifices in simultaneous operation, the discharge coefficient decreased, because of jets superposition within the tube and submergence of the orifices in the highest flows.