System for receiving and processing diversity acoustic noise control data

The results of the development and experimental verification of a system for obtaining and processing diversity acoustic noise control data are presented. The system is implemented using the LabView G graphical programming language. The length of the measured realization is determined by the ratio of the sample size to the sampling frequency. The number of measurements of each sound signal is determined by the ratio of the analysis time to the length of the measured realization. The measured audio signal implementation in the form of 40,000 16-bit binary numbers is processed using the fast Fourier transform. The result is a discrete spectrum of the audio signal in the range from 0 to 20 KHz with a step of 1 Hz. The results of the system check using a laboratory acoustic chamber and a noise shield are presented. The advantages and disadvantages of the system are formulated.

Investigation of Check Valve Aerodynamic Characteristics in Different Operating Modes

The paper presents a computational study of the NPP ventilation system check valve aerodynamics, namely, a numerical simulation of the air flowing through the open valve with the subsequent determination of the relationship between the reactive torque acting on the valve closure axles and the input air velocity.This numerical simulation of the air flowing through the check valve was performed using the ANSYS CFX program. In the computation, different operating modes of the check valve were considered when the air flow was passing through it. The valve operating modes were set depending on changes in the input air velocity. As a result of aerodynamic computation, the values of pressure and velocity components were obtained over the entire valve volume.Reactive forces were calculated in the ANSYS Mechanical program. The reactive forces acting on the valve body form a torque at the gate axles. When adjusting the check valve to the actual flow rate, it is necessary to know this torque value and compensate for it. As a result of a series of computations of reactive forces, a relationship was found between the torque value of the valve’s working element axles and the input air velocity.

Measurement Principle of Glass Thermal Expansion Coefficient and Technology Application of DIL402PC Dilatometer

The paper introduces the measuring principle of glass thermal expansion coefficient. It expresses the features and advantages of the linear variable differential transformer measuring principle by comparing the thermal expansion coefficient measurement methods analysis. Meanwhile, the paper introduces DIL402PC dilatometer measuring devices and measurement procedures. It use standard samples to execute thermal expansion instrument system check from the accuracy and repeatability. The result shows thermal expansion coefficient of linear expansion instrument bias of DIL402PC dilatometer is within the error range of the theoretical value. The process proves it has a wide range of applications.