RU39713U1 - DEVICE FOR MEASURING THE AVERAGE WATER SPEED IN OPEN WATERS - Google Patents

Abstract

A useful model of the device relates to the field of hydrometry, in particular to measuring the speed of water flow in open channels. The task of creating a useful model is to increase the accuracy and reliability of measuring the speed of the fluid flow. The solution is achieved by the fact that the hydrometric rails are rigidly connected to each other at an acute angle, and the node of their connection is equipped with a counterweight and pivotally attached to a pallet located at the bottom of the channel of the watercourse. The device in the proposed device is a system in the form of a block of hydrometric rails and weight pivotally connected to the pallet. In addition, a new method has been applied to determine the average water velocity based on converting the difference of current readings from two identical hydrometric rails and the angle of their deviation relative to the vertical to the value of the water velocity.

Description

The device relates to the field of hydrometry and can be used to measure the average speed of water in river channels and irrigation and drainage channels.

A device for determining the average speed of water or other flows / 1 /, containing a flexible plate, rotationally mounted at the ends and rigidly fastened protruding from the stream end with an arrow, so that its angle is dependent on the average speed of the measured layer of flow . The average flow rate is a function of the dynamic pressure on the flexible plate and the depth of the water stream.

During operation of the device, a variable value of the dynamic pressure of the flow on the working surface of the plate, which depends on the depth of flow, has a significant effect on the error in measuring the average speed. The device is more effective at large depths of the water flow, since in this case the working surface of the flexible plate is maximum. In cases of small flow depths due to the reduced area of the working surface of the flexible plate, the measurement error will increase, and their reliability will depend on the calibration frequency of the device, which complicates operation and reduces the reliability of the device.

The closest in technical essence to the proposed utility model is a device for measuring small water flow velocities of a structure V. E. Vida / 2 /, containing a hydrometric pole elastically fixed with its lower end to a pallet of a fixed vertical rod and a horizontal measuring rail, one

the end of which is movably fixed on the rod, and the second is equipped with a float to hold the measuring rod on the surface of the water. The average vertical speed is a function of the deflection angle of the gauge pole and the length of its wetted part.

The disadvantage of this device is the need for periodic movement of the measuring rod when the level changes. With the recommended placement of the device in the stream, this complicates the operation of the device and reduces the reliability of its operation.

The task of creating a utility model is to simplify the design and operation of the device. This is achieved by using two identical hydrometric rails rigidly connected to each other at an acute angle, and the node of their connection is provided with a counterweight and is pivotally attached to a pallet located at the bottom of the channel of the watercourse.

To simplify the operation of the device, the gauge rails have the same line measure of length, which makes it possible to remotely visualize information from the gauge rails and calculate the average water velocity without adjusting the position of the device elements.

Figure 1 shows a device for measuring the average speed of water in open streams.

The design of the device includes two hydrometric rails 1 and 2, the lower ends connected to each other at an acute angle a, and the connection node of the hydrometric rails 3 is pivotally connected to a pallet 4 located at the bottom of the channel of the watercourse, and is rigidly combined with a counterweight 5.

The device operates as follows.

After placing the structure in the water stream, with the condition of stable placement of the sump 4 at the bottom of the channel of the watercourse, hydrometric

the rails 1 and 2 will have a hydrodynamic effect proportional to the speed of the water flow and deflecting the hydrometer rails 1 and 2 in the direction of flow. Counterbalance 5, through the junction of the rails 3, counteracts a change in the initial position of the hydrometer rails 1 and 2. With an increase in the flow rate, the hydrodynamic effect increases, which further changes the position of the hydrometer rails 1 and 2. The corresponding change in the position of the counterweight 5, provided by the hinged connection of the hydrometer rails 3 with a pallet 4, increases the magnitude of the rotation moment compensating for the increase in hydrodynamic effects on the hydrometric rails 1 and 2. The average speed s flow of water by the stream depth is determined by the formula V = KΔh,

where K is the compliance coefficient determined during the calibration of the device;

Δh is the difference in the readings of the current water level on the first and second hydrometric rails.

Improving the accuracy of measuring the average velocity of the water flow is achieved by the absence of an additional horizontal measuring rail and the exception of its influence on the total error of the device. The independence of the measurement process Δh from the current water level in the channel of the watercourse greatly simplifies the operation of the device and the reliability of determining the speed of water. The introduction of a counterweight instead of the elastic connection of the measuring element with the pallet increases the stability and reliability of measuring the average flow rate.

Claims (1)

A device for measuring the average speed of water in open streams, containing two hydrometric rails, lower ends fixed to each other in a pan located at the bottom of the channel of the water stream, characterized in that the hydrometer rails are the same length and are rigidly connected to each other at an acute angle, and their node the connection is combined with a counterweight pivotally connected to the pallet.