A Method of Rapid Measurement of Vessels Volume with Complex Shape by Critical Nozzles

A subject of the study is ways to determine the volume of vessels with complex shapes. The work aims to develop and scientifically substantiate a rapid method of measuring the volume of the vessel’s inner cavity with complex geometric shapes. The following results were obtained. Invented method of rapid measurement of the vessel volume with complex shape bases on a critical outflowing filled gas and its drainage through a nozzle with a predetermined discharge coefficient. The dynamic pressure change in a vessel is a determining parameter of its volume. Two conditions must be met for this method to be accurate. The first one is the calming of transients in the measured vessel after the beginning of gas critical outflow and the second is providing an adiabatic flow. The proposed method of measuring the vessel volume was checked by simulating. Obtained results show the accuracy of determining the volume of about 0.06% compared with CAD system data. In practice, the measurement by the method should be performed in two stages. At the first stage, the value of the nozzle discharge coefficient must be found based on the results of the control measurement when flowing out of the etalon vessel with a known volume. At the second stage, the required volume is determined using the found nozzle discharge coefficient. We expect the duration of the direct measurement by the invented method up to 1 s and its accuracy by about 0.1%.