Shock the camera to determine the hydrodynamic characteristics of the profile of the bottom of the studied body

 

(57) Abstract:

Usage: in experimental hydrodynamics to study the processes of immersion of solids in the liquid through its free surface. The inventive wall of the first branch is equipped with attached plates with elastic strips at their upper ends, with the possibility of contact with a test body and mates with him when profiling, and the lower ends of these plates immersed in the liquid. 2 Il.

The invention relates to experimental hydrodynamics and applied to the study of the processes of immersion of solids in the liquid through its free surface.

Known shock the camera to determine the hydrodynamic characteristics of the profile of the bottom of the studied body containing a V-shaped partially fluid-filled vessel, the first of branches which are executed with the possibility of placing in her of the investigated body, and the upper part of the second branch through the valves communicated with a source of compressed air in the receiver and provided with a floating piston.

A disadvantage of the known shock camera is the low accuracy of determination in her hydrodynamic characteristics of the models profiles dreamyh models profiles phone bottoms

The purpose of the invention to improve the accuracy of determination of the hydrodynamic characteristics of the models of the bottoms of the test bodies by eliminating the flow of fluid in the gaps between the ends of the tested model and the walls of the working parts of the camera.

This objective is achieved in that the wall of the first branch is equipped with attached plates with elastic strips at their upper ends, with the possibility of contact with a test body and mates with him when profiling, and the lower ends of these plates are immersed in the said liquid.

In Fig. 1 shows the described shock chamber, the cross-section of Fig. 2 is a view along arrow a in Fig. 1.

The basis of the shock chamber is V-shaped vessel, partially filled with liquid. His broad knee 1 are connected by a pipe 2 with a knee 3 having smaller cross sectional area than the knee 1, and a transparent wall. Narrow knee 3 is the working part of the shock chamber for placing an experience of the body. It communicated with the upper tank 4. The pipe 2 is placed perforated plate 5, the role of hydraulic resistance, and the rotary stream directing vanes 6. In a wide knee 1 is the ha in the form of an air receiver 8 through the duct, equipped with a quick-acting valve 9. Draining the liquid from the upper tank 4 in a wide knee 1 is made through a pipeline with a valve 10. Fill the shock chamber fluid through the valve 11 and the discharge of fluid through the valve 12. In the working part of the shock chamber near its middle on the rigid base 13 is installed sensors 14 forces and moments at which a clearance to the walls can be fastened in the analyzed model of the bottom 15, which can be mounted on the plate 16 attached to the side walls of the test section of the shock chamber (narrow knee 3) through the elastic strip 17 having the ability to pair with a bottom 15 when profiling. To determine the flow velocity in the working section on the wall of the fixed high-speed sensor 18. A pressure gauge 19 is designed to control air pressure in the receiver 8. The piston 7 in a wide knee 1 is connected with a lever with release valve 20.

The experiments proposed in shock camera are as follows.

In the knee 1 through the valve 11 is poured to the desired level of the liquid. The air tank 8 when closed valve 9 is filled with compressed air, the pressure of which is controlled by a pressure gauge 19. Venue.

The experiment begins with a fast opening valve 9 and the simultaneous operation of the recording equipment. Compressed air is supplied to the upper part of the wider tribe 1 and creates pressure on the piston 7. Under the action of the pressure piston 7 displaces the liquid from the wide knee 1 through pipe 2 to the knee 3.

Due to the fact that the ends of the plates are lowered into the fluid perturbations of the free surface of the liquid in the working part of the camera (knee 3) does not occur.

Initially the fluid is moving at a significant speed-UPS. As the growth speed of the flow increases dramatically retarding action of the plate 5. When the force acting on the liquid side of the compressed air, compared with the braking force flow rates, the liquid velocity in the shock chamber is set constant.

The path traversed by the free liquid surface in the test section of the shock chamber from the beginning of the experiment to establish a constant flow rate depends on the initial excess pressure in the receiver 8 and the ratio of the perforation plate 5, but should not exceed the distance from the initial level of fluid in the knee 3 to the bottom part of the study model plate 15.

Ptmodel bottom 15. The process of meeting model bottoms with a free surface and its further penetration into the liquid are captured by film or photography through the transparent wall of the knee 3. The signals from the sensors 14 are set by the DC amplifier and recorded on Daisy oscilloscope. The high-speed signals of the sensor 18 may also be recorded on the oscilloscope. Elastic strip 17 being deformed during the experiment (when the fluctuations of the studied models) prevent the penetration of liquid into the gaps between the ends of the model and the walls of the working parts of the camera.

When the movement of the piston 7 selects the excess length of the rod, connected to a release valve 20, and after the fluid flow reaches the top of the knee 3, the valve 20 opens, venting to the atmosphere the compressed air from the upper part of the knee 1. Quick-acting valve 9 is closed. This experiment is terminated.

The liquid caught during the experiment in the upper tank 4 is returned in a wide knee 1 after opening of the valve 10. After its closing the shock Luggage ready for the next experiment.

Using the described shock of the camera by wrapping the tested models bottom only Dahmer audouze with constant velocity through the free liquid surface of the investigated model of the bottom, and get pictures and kilogramme flow model of the bottom, providing an assessment of the impact of the shape of the model plate and the flow velocity on the nature of the flow and intensity of Bryzgalova. When changing one of the model on another change and plates, repeating its shape.

SHOCK the CAMERA TO determine the HYDRODYNAMIC CHARACTERISTICS of the PROFILE of the bottom of the STUDIED BODY containing a V-shaped partially fluid-filled vessel, the first of branches which are executed with the possibility of placing in her of the investigated body, and the upper part of the second branch through the valves communicated with a source of compressed air in the receiver and provided with a floating piston, characterized in that the wall of the first branch is equipped with attached plates with elastic strips at their upper ends, with the possibility of contact with a test body and mates with him when profiling, and the lower ends of these plates are immersed in the said liquid.

 

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