KR20090034012A - Automated wake measurement system - Google Patents

Abstract

An automatic stern reverse flow instrumentation system is provided that the task efficiency is guaranteed since the wakerake measures the reverse flow. An automatic stern reverse flow instrumentation system comprises a wakerake(110) which measures the distribution of the transmitted echo formed in the tail end of propeller shaft, a measurement device(100) which includes an encoder(120) and a servo motor(130) rotating the wakerake within 0~360 degree, and a PC(Personal Computer)(200) which calculates the flux of the transmitted echo formed in the tail end of propeller shaft.

Description

Automated wake measurement system

The present invention relates to an automated stern backflow measurement system that eliminates the long axis present in existing measurement systems and allows wakerakes to automatically measure the return distribution with angle conversion.

1. Existing Return  Instrumentation system

Conventional return measurement systems are installed in the cavitation tunnel to perform their functions (Fig. 1, C), but when not in use, the wakerake and shaft support A are removed and the long axis with vinyl tubes installed is supported by the shaft support B (Fig. 1, C). 2 is moved to the position of (see Fig. 1, D).

2. Inefficiency of the experiment

In the wake measurement system, the wakerake is intended to measure the distribution of the stern wake, so that the angle can be changed from 0 to 360 degrees. To this end, the conventional reflux measurement system has two control levers outside the cavitation tunnel, one of which is a translation lever that can move the axis back and forth, and the other which is a rotation lever that can rotate the axis from 0 to 360 degrees.

However, the measurement of the flow rate distribution is generally carried out over about 30 angles, and the adjustment levers have to be manually adjusted. When the experiment is finished, turn the rotary lever to change the wakerake to the next angle. At least one researcher had to participate in the experiment for a long time.

3. Problems with Maintenance

In case of the conventional reflux measurement system, the vinyl tubes are installed inside the long axis of more than 10m. If the vinyl tubes are damaged and the leak occurs, the long axis must be removed from the cavitation tunnel to replace it, and the vinyl tube is installed inside the long axis. It took a long time to find the site, but it took a lot of time and manpower to dismantle and reassemble the long axis. As a result, the maintenance period was typically around 10 days.

Further, as shown in FIG. 1, since the long axis is removed from the cavitation tunnel (C → D), the laboratory must secure a space longer than the long axis length, and thus there is a problem in that the space of the building cannot be efficiently used.

On the other hand, this maintenance is also a problem, but due to the lack of other experiments during the maintenance period, the utilization of the cavitation tunnel was inevitably low, and there was a considerable difficulty in planning the maintenance.

4. Increased background noise

To perform noise tests in a cavitation tunnel, the background noise level of the cavitation tunnel itself must be lowered. At this time, the presence of various additives in the cavitation tunnel may increase the background noise by that much.

In the case of the conventional reflux measurement system, the cavitation generated from the propeller affects the shaft support B and the rear vane shown in FIG. Thus, the existing wake measurement system had to be removed to conduct noise studies in the propulsion system in the cavitation tunnel.

5. Problems with Installation

In the conventional reflux measurement system, the shaft support B is fixed, but the shaft support A, which is similar in shape to the shaft support B, is detachable and needs to be separately installed. At this time, the difference in the installation time and degree of the shaft support A according to the skill of the installer, there was a problem that the experimental results also differ depending on the installer.

In addition, after the installation of the shaft support A, all 20 or more vinyl tubes installed in a long shaft of 10 m or more have to be removed and filled with water. The length of the vinyl tube is long, and it takes a long time to remove the air (installation and experimentation). Preparation time about 8 hours).

The present invention has been proposed to solve the above problems, by eliminating the long axis existing in the existing measurement system and by measuring the wake distribution while the wakerake automatically converts the angle, the installation and maintenance of the system becomes easier and experimental It is an object of the present invention to provide an automated stern backflow measurement system that allows for higher efficiency.

Other objects and advantages of the present invention will be described below, which are not limited to the matters set forth in the claims and the disclosure of the embodiments thereof, but also to the broader ranges by means and combinations within the range readily recited therefrom. Add that it will be included.

In order to achieve the above object, the present invention, the wakerake (110) for measuring the distribution of the backflow formed at the rear of the propeller shaft while automatically rotating in the cavitation tunnel observer, and the wakerake (110) 0 to 360 degrees A measurement device 100 including an encoder 120 and a servomotor 130 rotating up to and including; And calculating and storing the flow velocity of the return flow formed at the rear of the propeller shaft from the information received from the wakerake 110 and rotating the wakerake 110 with respect to the encoder 120 and the servomotor 130 at the next measurement angle. While the wakerake 110 rotates 360 degrees and completes all the measurements, the PC 200 includes a PC 200 for deriving the flow velocity distribution of the return flow formed at the rear of the propeller shaft. A stern wake measurement system is presented.

According to the present invention, the wakerake measures the regurgitation distribution while automatically converting the angle from 0 degrees to 360 degrees, so that the work can be efficiently performed as the relevant research personnel are put into other tasks during the experiment. Later, the present invention is removed from the cavitation tunnel so that other experiments can be performed even during the maintenance period. In the present invention, the long axis existing in the existing measurement system disappeared, so that the laboratory can be stored in various spaces for storing and assembling equipment. Not only can be utilized, but also the background noise of the tunnel can be improved at the same time, and the present invention can be easily and simply installed because it is composed of a streamlined body and a fully assembled type with a wakerake on an aluminum window made of specifications such as a cavitation tunnel.

Other effects of the present invention, as well as those described in the above-described embodiments and claims of the present invention, as well as potential effects that may occur within the range that can be easily estimated therefrom and potential advantages that contribute to industrial development It will be added that it will be covered by a wider scope.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals have the same reference numerals as much as possible even if displayed on different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, the following will describe a preferred embodiment of the present invention, but the technical idea of the present invention is not limited thereto and may be variously modified and modified by those skilled in the art.

1. Overview of the Invention

Automated stern reflux measurement system according to the present invention, the wakerake (110) and wakerake (110) for measuring the distribution of the return formed in the rear end of the propeller shaft while automatically rotating in the cavitation tunnel observer from 0 to 360 degrees The flow rate of the return flow formed at the rear of the propeller shaft is calculated and stored from the measuring device 100 including the encoder 120 and the servomotor 130 to rotate, and the information received from the wakerake 110, and the encoder 120 and It sends out a command to rotate the wakerake 110 to the next measurement angle with respect to the servomotor 130, and when the wakerake 110 rotates 360 degrees and completes all the measurements, the acquired results are arranged and formed at the rear of the propeller shaft. And a PC 200 for deriving the flow velocity distribution of the wake.

In the automated stern reflux measurement system according to the present invention, in order to reproduce the flow distribution of the model ship stern in the cavitation tunnel, the reflux screen is superimposed on the basis of the stern flow distribution on the model ship propeller surface measured in the towing tank. (300, see FIG. 4) to be installed in the mounting screen installation position shown in FIG.

At this time, the measuring device 100 has a streamlined body in order to induce a smooth fluid flow in the cavitation tunnel. In addition, there is a central axis 140 that connects the wakerake 110 and the servo motor 130 to each other to transfer the rotational force of the servo motor 130 to the wakerake 110 inside the body.

On the other hand, since the measuring device 100 is attached to the aluminum window 500 made of the same specification as the cavitation tunnel and is integrally formed, the measuring device 100 is lifted up by the crane and placed on the upper part of the cavitation tunnel observation unit and fixed. You can finish the installation.

The propeller shaft moves the wakerake 110 position to the propeller surface, and constantly adjusts the cavitation tunnel observation flow velocity to measure the flow velocity distribution.

The Wakerake 110 is provided with ten pitot tubes 111, and the velocity distribution in the radial and circumferential directions can be obtained by measuring the speed while changing from 0 degrees to 360 degrees.

The flow rate measured at the wake screen 300 and the flow rate distribution measured at the wake of the model ship stern are compared to repeat the process of modifying and measuring the wake screen 300 until there is almost no difference.

The automated stern wake measurement system according to the present invention has the following characteristics.

2. Efficiency of work

Wakerake (110) is intended to measure the distribution of the return flow, so it must be possible to change the angle from 0 to 360 degrees. In order to improve the inefficiency of the existing measurement system by manually adjusting the angle by the excessive input of research personnel, in the automated stern reflux measurement system according to the present invention, the servomotor 130 in the measurement device 100 having a streamlined body. ) And an encoder 120 attached to the data acquisition PC 200 and configured an automated measuring device that rotates to the next measurement angle when the measurement is made at one angle.

If the reflux screen 300 is installed in the cavitation tunnel and only the data acquisition program is operated on the PC 200, a series of experiments will be performed and analysis of the results will be performed automatically. As the relevant research personnel are put into other tasks during the experiment, the work can be made more efficient.

3. Convenience of maintenance

The present invention is removed from the cavitation tunnel after the end of the experiment, so that no other experiment is performed during the maintenance period. Existing metrology system was not able to utilize a considerable amount of space separately in the laboratory to secure a maintenance space, according to the present invention can be used as a variety of space for storage of goods and equipment assembly.

The streamlined body of the measuring device 100 according to the embodiment of the present invention has a length of about 2m, and can be disassembled into four parts so that maintenance can be performed immediately when the vinyl tube is replaced or the servomotor 130 is broken. It was configured to. In the case of replacing the servo motor 130 and the vinyl tube, it is possible to work within 1 day.

4. Background Noise Reduction

In the automated stern reflux measurement system according to the present invention, it is possible to improve the tunnel background noise by removing the long axis and two shaft supports A and B (see FIG. 1) inherent in the vinyl tubes existing in the existing measurement system.

In particular, in the existing measurement system, the cavitation generated from the propeller affects the support and the long axis, resulting in secondary noise.In the case of high tunnel flow rate, the noise is large due to the flow problem caused by the installation of the long axis at the 90 degree bend. There was a difficulty in performing the noise test occurred, this problem was solved by the present invention.

5. Convenience of installation

Since the measuring device 100 according to the present invention is integrally attached to the aluminum window 500 made of the same specification as the cavitation tunnel, only the aluminum window 500 is lifted by the crane and placed on the upper part of the cavitation tunnel observation unit. The installation can also be completed (see FIG. 5).

Since the aluminum window is installed on the machining surface of the cavitation tunnel observer, no separate centering adjustment is required, and even a beginner's installation does not have any problem. The installation time is much shorter than the existing measurement system, and the length of the vinyl tube is also shortened, which shortens the time to remove air inside the vinyl tube (about 2 hours for installation and experiment).

6. Automated stern according to the present invention Return  By measuring system Return  Metrology process

When the installation of the automated stern reflux measurement system according to the present invention as shown in FIG. 3 is completed, the flow rate of the cavitation tunnel observer is adjusted.

The central axis 140 connected to the wakerake 110 at the center of the streamlined body of the measuring device 100 at a constant flow rate is connected to the servo motor 130 and the encoder 120 to adjust the experimental angle of the wakerake 110. As 20 vinyl tubes are installed in the central axis 140, the rotation is rotated ± 180 degrees.

Wakerake (110) has 10 pitot pipes (111) are installed for each radius in the central axis (140) can obtain a distribution of the flow rate in the maximum 10 radii during the experiment. The pitot pipe 111 has a hole for measuring the dynamic pressure and the static pressure, the flow rate can be calculated using the pressure difference between the dynamic pressure and the static pressure (Bernui principle). Since two vinyl tubes are connected to one pitot tube 111, a total of 20 vinyl tubes are connected to the central axis 140, and dynamic pressure tubes are connected to the dynamic pressure pipe wafer 410 and positive pressure tubes are connected to the positive pressure pipe Wafer 420. do.

Wafer is an accessory of the swan valve so that the positive pressure and dynamic pressure pipes of the same pitot pipe 111 are connected to the differential pressure type pressure sensor. That is, Wafer is an apparatus that can measure the pressure values acquired from the ten pitot pipes 111 by one pressure sensor, which has the advantage of obtaining a consistent measured value.

When pressure measurement is performed at various radii at one angle and transmitted to the PC 200 through an amplifier and an A / D converter, the PC 200 calculates and stores the flow rate and wakewake 110 at the next measurement angle. Send a command to rotate. All these tasks are performed on one PC 200.

Experiments are performed at about 40 angles, and when all experiments are completed, the obtained results can be rearranged to obtain a flow rate distribution as shown in FIG. 6. All of these tasks are automatically performed when the data acquisition program is operated on the PC 200.

The above description is merely illustrative of the technical idea of the present invention, and various modifications, changes, and substitutions may be made by those skilled in the art without departing from the essential characteristics of the present invention. will be. Accordingly, the embodiments disclosed in the present invention and the accompanying drawings are not intended to limit the technical spirit of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by the embodiments and the accompanying drawings. . The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 shows a conventional wake measurement system.

FIG. 2 shows the shaft support B shown in FIG. 1.

3 shows an automated stern reflux measurement system according to the present invention.

4 shows a wake screen 300 according to the present invention.

5 shows a situation of installing the measuring apparatus 100 according to the present invention.

Figure 6 shows the flow rate distribution measurement results of the wake formed at the rear of the propeller shaft derived by the automated stern wake measurement system according to the present invention.

<Description of Major Symbols in Drawing>

100: measuring device

110: wakerake

111: pitot tube

120: encoder

130: servo motor

140: central axis

200: PC

300: return screen

410: dynamic pressure pipe Wafer

420: Positive Pressure Tube Wafer

500: aluminum window

Claims (11)

A wakerake 110 for measuring the distribution of the return flow formed at the rear of the propeller shaft while automatically rotating in the cavitation tunnel observer, and an encoder 120 and a servomotor for rotating the wakerake 110 from 0 degrees to 360 degrees. A measuring device 100 comprising a 130; And From the information received from the wakerake (110) to calculate and store the flow rate of the return flow formed at the rear of the propeller shaft and to rotate the wakerake (110) with respect to the encoder 120 and the servo motor 130 to the next measurement angle On the other hand, when the wakerake 110 completes all the measurements while rotating the 360 degrees, the PC 200 generates a flow velocity distribution of the return flow formed at the rear of the propeller shaft by arranging the obtained results. Automated stern reflux measurement system comprising a. The method of claim 1, The automated stern reflux measurement system according to claim 1, In order to reproduce the flow distribution of the model ship stern in the cavitation tunnel, it further includes a reflux screen 300 fabricated by superimposing brass meshes based on the stern flow distribution on the model ship propeller surface measured in the towing tank. Automated Stern Return Measurement System. The method of claim 1, The measuring device 100, Automated stern reflux measurement system, characterized by having a streamlined body. The method of claim 1, The measuring device 100, It further comprises a central axis 140 for connecting the wakerake 110 and the servo motor 130 in the body to transfer the rotational force of the servo motor 130 to the wakerake (110). Automated Stern Return Measurement System. The method of claim 1, The measuring device 100, It is attached to the aluminum window 500 made of the same specification as the cavitation tunnel, and is integrally formed. The aluminum window 500 is lifted by a crane and placed on the upper part of the cavitation tunnel observation unit. Automated Stern Return Measurement System. The method of claim 1, The wakerake 110, Automated stern reflux measurement system, characterized in that a plurality of pitot pipes 111 having a hole for measuring the dynamic pressure and static pressure of the back flow formed at the rear of the propeller shaft is installed in the central axis 140 by a radius. The method of claim 6, The wakerake 110, Automated stern reflux measurement system, characterized in that a total of 10 pitot pipes (111) are installed at regular intervals for each radius in the central axis (140). The method of claim 6, In each of the pitot tube 111, An automated stern backflow measurement system, characterized in that two vinyl tubes (static pressure pipe and dynamic pressure pipe) corresponding to a hole capable of measuring dynamic pressure and static pressure are connected. The method of claim 8, Automated stern reflux measurement system, characterized in that all of the vinyl tube (static pressure tube and dynamic pressure tube) connected to each of the pitot tube 111 is embedded in the central axis (140). The method of claim 8, An automated stern reflux measurement system according to claim 8, Automated stern reflux measurement system, characterized in that it further comprises a wafer to collect the vinyl tube (static pressure tube and dynamic pressure tube) of the pitot tube 111 and connect it to the differential pressure type pressure sensor. The method of claim 10, The wafer, Automated stern backflow measurement system, characterized in that divided into a dynamic pressure pipe Wafer (410) to gather only the dynamic pressure pipe, and a positive pressure pipe Wafer (420) to gather only the positive pressure pipe.

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