Modelling the Force Action of a Liquid on the Shutter of a Measuring Transducer

The article describes the original design of the measuring transducer of angular velocity of the type “flapper-nozzle “. The aim of the study is mathematical modeling in the MathCAD program of the force action of liquid jets exiting nozzles, since this significantly affects the characteristics of the converter. The calculated values of the acting forces are compared by several known methods and their results are compared with experimental data. For the proposed design of the measuring transducer, greater convergence of the theoretical and experimental values of the power characteristic in the linear section is provided by the expressions for determining the force effect of two jets on the damper, defined as the hydrodynamic effect of the liquid jet on the obstacle. Given the real differences in the design of the converter from theoretical models, it is required to apply correction factors. As pressure increases, the coefficient increases from 1 to 1.24-1.30 depending on the pressure supplied to the measuring transducer and the version of expression used to calculate it. When using the expression for the approximate calculation of the acting forces in the converter, the correction factor is much higher and varies from 1.9 at a supply pressure of 0.5 MPa to 1.74 at a supply pressure of 1.5-2.0 MPa. The practical use of this calculation option is limited to the linear zone of pressure dependence in the working chambers of the converter on the gap between the nozzles and the shutter