Application of Multiparameter Kalman Filter in Ultrasonic Water Meter

With the gradual development of the superior performance of the ultrasonic water meter, the use of the water meter gradually occupies most of the market due to its unique advantages. Through the analysis of the influencing factors of the ultrasonic water meter, the Kalman filter is used to analyze the influencing factors, and the differences are obtained. In this paper, combined with the application scope of the Kalman filter, it is introduced. Combined with the method of data fusion, the influencing factors of the ultrasonic water meter are analyzed. They are the flow rate, temperature, speed of sound, time difference, etc. The appropriate sensor is selected through the sensor selection method, and the corresponding data is obtained by the method of the corresponding sensor. We combine the data fusion method and use Kalman’s method to filter the data. By comparing the data before and after the processing, it is found that the data before and after the filtering of different influencing factors are small. Among them, the flow speed factor has the greatest impact on the accuracy of the ultrasonic water meter; temperature and sound velocity have little effect on the performance of the ultrasonic water meter. When designing an ultrasonic water meter, it is mainly necessary to consider the impact of flow rate and time difference on the performance of the ultrasonic water meter.

Blood flow in the umbilical vein of the fetus in first half of pregnancy

The present investigation aims at studying the blood flow in the umbilical vein in the first half of normal pregnancy. It was shown that the establishing of hemocirculation passes through 4 periods: 8- 10th, 11-12th, 13-16th and after the 16th week of pregnancy. Besides that, statistically verified changes in maximum blood flow speed and index of pulsation in this vessel were revealed. Constant bloodstream spectrum reflects stability of oxygenic bloodsupply of the fetus.

Determine the parameters of PID algorithm in liquid level control controlled by PLC s7 1500 using 3d virtual reality model

It is very common to stabilize the preset value (Wanted value) of analog signals such as temperature, pressure, weight, flow, speed in automatic control. However, these control objects often have some problems such as overshooting, taking a long time to bring the system to a steady value, and large errors. One of the most used systems to overcome these problems is the PID, which is a preset stabilizing system with a quick function that returns the system to the set value in a short time without overshooting. error is close to zero. However, determining the scale parameters Ki, integral Kp, and differential Kd for the system to work optimally is a problem that needs to be studied. This paper presents how to accurately determine differential, integral, and scale coefficients according to 3D virtual reality model. Used a lot in simulation modeling for training and practical applications.

Under pressure: turbulent plumes in a uniform crossflow

Direct numerical simulation is used to investigate the integral behaviour of buoyant plumes subjected to a uniform crossflow that are infinitely lazy at the source. Neither a plume trajectory defined by the centre of mass of the plume $z_c$ nor a trajectory defined by the central streamline $z_{U}$ is aligned with the average streamlines inside the plume. Both $z_c$ and $z_{U}$ are shown to correlate with field lines of the total buoyancy flux, which implies that a model for the vertical turbulent buoyancy flux is required to faithfully predict the plume angle. A study of the volume conservation equation shows that entrainment due to incorporation of ambient fluid with non-zero velocity due to the increase in the surface area (the Leibniz term) is the dominant entrainment mechanism in strong crossflows. The data indicate that pressure differences between the top and bottom of the plume play a leading role in the evolution of the horizontal and vertical momentum balances and are crucial for appropriately modelling plume rise. By direct parameterisation of the vertical buoyancy flux, the entrainment and the pressure, an integral plume model is developed which is in good agreement with the simulations for sufficiently strong crossflow. A perturbation expansion shows that the current model is an intermediate-range model valid for downstream distances up to $100\ell _b$ – $1000 \ell _b$ , where $\ell _b$ is the buoyancy length scale based on the flow speed and plume buoyancy flux.

Characterisation of Single-Phase Fluid-Flow Heterogeneity Due to Localised Deformation in a Porous Rock Using Rapid Neutron Tomography

The behaviour of subsurface-reservoir porous rocks is a central topic in the resource engineering industry and has relevant applications in hydrocarbon, water production, and CO2 sequestration. One of the key open issues is the effect of deformation on the hydraulic properties of the host rock and, specifically, in saturated environments. This paper presents a novel full-field data set describing the hydro-mechanical properties of porous geomaterials through in situ neutron and X-ray tomography. The use of high-performance neutron imaging facilities such as CONRAD-2 (Helmholtz-Zentrum Berlin) allows the tracking of the fluid front in saturated samples, making use of the differential neutron contrast between “normal” water and heavy water. To quantify the local hydro-mechanical coupling, we applied a number of existing image analysis algorithms and developed an array of bespoke methods to track the water front and calculate the 3D speed maps. The experimental campaign performed revealed that the pressure-driven flow speed decreases, in saturated samples, in the presence of pre-existing low porosity heterogeneities and compactant shear-bands. Furthermore, the observed complex mechanical behaviour of the samples and the associated fluid flow highlight the necessity for 3D imaging and analysis.

STATIC CONTROL OF DRAG-REDUCING AIR CAVITIES WITH VARIABLE CAVITATOR SHAPE

Air ventilation of submerged surfaces of ship hulls is a promising technique for drag reduction. To ensure high performance of air cavities in a broad range of operational conditions, the cavity properties can be controlled with help of compact hydrodynamic actuators. In this study, a potential flow theory is applied to model an air cavity formed behind a wedge-shaped cavitator under a horizontal wall imitating a ship bottom. By varying the wedge angle, it is possible to achieve states with maximum drag reduction at given operational conditions. The dependence of the optimal wedge angle on Froude number and hull trim is investigated. The air-cavity ability to reduce frictional drag is found to increase with rising flow speed and bow-down hull trim.