Use of wall-type electromagnetic velocity gauges to measure flow rate in largediameter water pipes

The following are determined in this study; the strength of the signal received from the electrodes of wall-type flowmeters; the working region of the channel; flow rate with an asymmetric flow-velocity profile; error of measurement of flow rate with allowance for changes in hydrodynamic conditions and imprecise positioning of flowmeters in the cross-section of the pipe channel. Translated from Izmeritel'naya Tekhnika, No. 5, pp. 22–28, May, 1997.     

Increase in the accuracy of information measuring systems for measuring oil flow rate based on turbine oil discharge converters

Results are presented for theoretical research and modelling of a measuring channel for information measuring systems for the volume of oil with a turbine oil discharge converter. The possibility of increasing accuracy is established.     

A new approach to the velocity field investigation in case of the entry flow in curved pipes with circular cross section

Summary In this paper an analysis of a laminar flow in a bend preceded by the straight section is presented. The flow is supposed to be unperturbed far upstream, while far downstream it becomes fully developed. In the vicinity of the sharp junction between the, bended and the straight section, the solution is expanded in terms of integer powers ofe ^S quantity (S is reduced distance from the curvature onset along the pipe axis). The corresponding expansion coefficients were determined in order to provide the velocity field continuity across the junction.     

Laser plasma accelerated by an optical discharge moving in air at a hypersonic velocity

The results of computer simulations show that a pulsing optical discharge moving in the atmosphere at a hypersonic velocity creates a plasma stream propagating in the direction opposite to that of the discharge. The plasma is accelerated upon efflux from the high-pressure region into an “evacuated” channel created by the discharge. Analytical expressions were derived to evaluate the stream velocity, density, and radius depending on the discharge parameters.     

利用管道速度分布方程校准大口径气体流量计

通过测量口径为300 mm的圆管内的充分发展湍流测量面上的流速分布,获得流速分布曲线后,用指数分布式模型和统一分布式模型对比实验曲线.发现两种方程曲线上的点流速与实际流速较接近,且统一分布式较指数分布式在管中心部分更接近实际值,故将其作为充分发展湍流管段的流速分布式.从而实现直接用流速分布式和该面上的一点流速推算管道流量,作为标准流量来校准该管道中的流量计.使用该方法可以有针对性的对工业现场管道中的流量计进行校验.     

Experimental study on the discharge flow rate of binary mixture in a two-dimensional silo

In this work, the discharging process of the binary mixture composed of sphere and sphere-paired particles in a two-dimensional silo was studied. High-speed camera and self-developed particle tracking velocimetry (PTV) program were used to capture the flow behaviors of all particles. The key parameters of mixed flow, including coordination number, horizontal displacement and mechanical energy loss in the discharge process, were highlighted. It was found that the increase of sphere-paired particles can decrease the average coordination number of particles during the discharging process. The analysis about the loss of mechanical energy and the horizontal displacement of particles indicated that sphere-paired particles preferentially squeezed out sphere particles from fast flow field above the outlet. Moreover, an empirical formula was proposed to assess the influence of the proportion of sphere-paired particles on the discharge flow rate. Sphere-paired particles tended to hinder the discharging process, which was caused by the rotation around their centroids and the angular deflection close to angle of the hopper.     

Calculation of the velocity of a plasma flow in the nozzle exit section of a coaxial-electrode Hall accelerator

The velocity of a plasma jet in the nozzle exit section and the pressure in the discharge zone of a coaxial-electrode Hall accelerator have been calculated on the basis of the experimentally measured enthalpy, temperature, and electron concentration near the indicated section within the framework of a model of the magnetic hydrodynamics of a plasma flow. __________ Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 79, No. 3, pp. 102–108, May–June, 2006.     

Shadow method for measuring the average electron density in an ionized gas flow induced by a high-frequency barrier discharge

The electron density distribution in an ionized gas flow induced by a high-frequency barrier discharge has been investigated by an optical method. It has been shown that ion acceleration occurs mainly near the minima of the electron density, and the extremes in the temperature distribution are in antiphase with the corresponding extremes of the electron density. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 82, No. 2, pp. 364–370, March–April, 2009.     

Gas velocity profile in the turbulent flow of a gas suspension in a channel of annular cross section

On the basis of concepts concerning two dynamically independently acting zones of a stream in an annular channel and the existence of a universal velocity profile in each zone, the parameters of this profile are calculated for the carrying medium of the gas-suspension stream.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 28, No. 5, pp. 781–187, May, 1975.     

组合热膜探头在气体流速测量中的应用

介绍了一种用于测量气体流速的组合热膜探头,并对组合热膜探头的温度特性以及温度补偿性能进行了实验研究.实验结果表明,组合热膜探头在微小流速测量中具有较高的灵敏度,可以弥补毕托管在低速情况下测量误差较大的缺陷,且具有较好的一致性。