KR100500969B1 - Resistance dynamometer for towing tank test - Google Patents

Abstract

The present invention discloses a novel resistance dynamometer for towing tank testing.

In order to solve the problem of vertical and longitudinal displacement increase and horizontal resistance measurement according to high speed driving, the present invention is equipped with a servo drive that operates according to the vertical displacement of the model ship so that the model ship is always maintained at the initial setting position. This enables fast and accurate resistance measurement of high speed ships including catamarans.

Description

Resistance dynamometer for towing tank test

The present invention relates to a towing tank test of model ships, and more particularly to a resistive dynamometer.

The ship's main concern for ships is to focus on its capacity, speed and fuel consumption, given sufficient safety and stability, which depends primarily on the linearity below the ship's waterline. . Accordingly, when designing a ship, the linear model ship is towed at a predetermined speed in a towing tank and the resistance is measured to estimate the required engine horsepower of a solid ship.

FIG. 1 illustrates a resistance dynamometer of a towing tank, in which a clamp post P2 and a dynamometer post P1 are arranged back and forth on a frame F of a towing tank that travels on a tank, respectively, from which a support beam B2 is arranged. , B1 extends downward and is provided with a clamp K and an inspection part S at a lower end thereof. Above the posts P1 and P2, geared motors M1 and M2 are respectively provided to adjust the vertical position of the support beams B1 and B2.

The power section S under the support beam B1 of the dynamometer post P1 has a universal joint in front of the tow bar R by the main test system S1 supported by the support yoke Y. joint to J1), the towing point T of the model line L is coupled to the universal joint J2 in the middle of the tow bar R, and at the rear end of the tow bar R at a balance weight. W) is provided.

On the other hand, the clamp bar (B) is fixed to the model line (L) is selectively gripped and released by the clamp (K).

The role of the clamp (K) is the protection of the power unit (S) during acceleration and deceleration of the towing tank, that is, depending on the size of the tank, but the model ship (L) is quite large (for example, about 8 m in the 400m tank The weight (near 1t in length) has a very large inertial force, and the clamp K grips the clamp bar b during acceleration and deceleration of the towing tank to support all the loads of the model ship L, and the towing tank is a constant speed. When it reaches, the clamp bar b is released to enable the inspection unit S to measure the resistance.

During the towing test of the model ship L, various fluid forces act on the hull. When the model ship L is symmetrically supported, this is mainly due to the horizontal force applied in the front and rear directions of the ship, that is, the hull resistance to be measured. , Vertical fluid force is large.

Here, the hull resistance is dramatically increased in units of multipliers of the ship speed, and thus the vertical fluid force also increases significantly as the ship speed increases. Accordingly, during the towing test of the craft or the high-speed towing test, the vertical fluid force increases greatly, so that the vertical and longitudinal displacements of the model ship L are increased.

As a result, the model line L and the inspection unit S cause interference such as mutual contact, and the accuracy of the measured resistance is inevitably deteriorated as the resistance measurement in the horizontal direction changes.

This problem is particularly acute in catamarans, where catamarans with large lateral stability run faster than typical mono hulls, making the ship's ship's line speed faster. In addition to the hull, the lower surface of the bridge (bridge) connecting the two hulls (fluid) is subject to a problem that the vertical fluid force and the longitudinal displacement becomes larger.

In view of such a conventional problem, an object of the present invention is to prevent the interference between the model ship and the inspection unit irrespective of the ship speed of the model ship, and to maintain a constant inclination angle of the tow bar, in particular, to provide a resistance dynamometer suitable for towing test of high speed and catamaran ships. It is.

Resistance dynamics according to the present invention for achieving the above object,

A support post installed on the frame of the towed tank, a support beam extending downward therefrom, and a servo drive supported on a bracket provided at the bottom of the support beam and vertically operated in response to the vertical displacement of the model ship. And a measuring head installed at the lower end of the drive shaft and connected to the model ship.

According to this configuration, the servo drive unit operates according to the vertical or longitudinal displacement caused by the high speed of the model ship, and the measurement head is lifted to maintain it at the initial setting position. As a result, a precise and reliable towing test is possible.

EXAMPLE

Such specific features and advantages of the present invention will become more apparent from the following description of the preferred embodiments with reference to the accompanying drawings.

2A and 2B, a support post 3 is provided on the frame F of the towing vehicle traveling on the tank and the support beam 31 supported thereon extends downward.

A bracket 32 is installed at the lower end of the support beam 31 to support the servo drive unit 1. Preferably, the servo drive unit 1 is a servo motor installed vertically to the bracket 32. 11), the measurement head 2 is supported below the drive shaft 12. Guide rods 13 are preferably provided on the left and right sides of the drive shaft 12 to ensure vertical elevation of the measuring head 2.

The measuring head 2 preferably has a body 21 provided at the tip of the drive shaft 12. In the embodiment of FIG. 2, the clamp K and the inspection part S are provided before and after the body 21. do.

On the other hand, although not shown separately, suitable displacement measuring means for measuring the vertical or longitudinal displacement of the model line (L) is provided.

This displacement measuring means may consist of a suitable linear gauge which is installed near or before and after the towing point of the model line L.

As described above, the resistive dynamometer of the present invention operates as follows. When the clamp K is released when the model line L reaches a constant speed, the displacement measuring means measures the vertical displacement and / or the longitudinal displacement of the model line L. Accordingly, the servo drive unit 1 compensates the vertical position of the measurement head 2 to the initial setting position.

That is, when the model line L is pushed upward by the fluid force, the servomotor 11 rotates to push the measurement head 2 downward, and vice versa by performing the reverse operation. (2) and the model line (L) connected thereto is initially maintained in the vertical position.

Accordingly, no interference occurs in the horizontal force measurement due to the vertical displacement, so that the inspection unit S can always accurately measure the horizontal direction resistance.

Figures 3a and b show the resistance dynamometer of the present invention, which is particularly suitable for measuring the resistance of a pair of bars. In this embodiment, left and right adjustments consisting of a ball screw and the like on the left and right sides of the measuring head 2 and the body 21 in this embodiment. Means 22 are provided and measuring blocks 23 are provided on the left and right sides of the right and left adjusting means 22, respectively.

Preferably, the ball screw of the left and right adjusting means 22 is the left and right, the opposite screw is formed around the body 21 to adjust the distance between the two measuring blocks 23 by the rotation of one handle (24). .

Each measurement block 23 may be composed of only one clamp (K) and the other one only the inspection unit (S), but more preferably consists of a clamp (K) and the detection unit (S) pair, respectively.

This configuration is for measuring the resistance of the catamaran bar, when the clamp (K) and the inspection unit (S) is composed of a separate measurement block 23 can measure the total resistance of the catamaran at once, but the towing point is symmetrical Therefore, two or more repeated tests are required alternately from left to right, and each measuring block 23 requires the sum of the measured values of both the testing units (S) with the clamp (K) and the testing unit (S) to obtain the total resistance. Has measurement characteristics.

According to the present invention as described above it is possible to obtain a high accuracy and reliability of the horizontal resistance force by maintaining the model ship at the initial setting position at all times during the towing test of the high-speed craft model with a large vertical displacement, especially effective in designing high-speed craft including catamarans There is.

Accordingly, the present invention will ensure a quick and accurate towing test of the craft and catamarans.

1 is a side view showing the installation of the resistance dynamometer for the model ship in the towing tank.

2a and b is a front view and a side view of the resistance dynamometer according to the present invention,

3a and b are front and side views showing another embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

S: Power part K: Clamp

1: Servo Drive Part 11: Servo Motor

12: drive shaft 2: measuring head

21: body 22: left and right adjusting means

23: measuring block 3: support post

Claims (6)

In the resistance dynamometer for towing tank test, installed on a towing tank that runs on a tank tank, towing a model ship in the tank and measuring its resistance, A support post installed on a frame of the towing tank and a support beam extended downwardly from the support post; A servo drive unit supported on a bracket installed at the bottom of the support beam and vertically operated in response to the vertical displacement of the model line; A resistance dynamometer for a towing tank test, characterized in that it comprises a measuring head which is installed at the lower end of the drive shaft and connected to a model ship. The method of claim 1, Towing tank test resistance dynamometer, characterized in that the measuring head has a body which is installed at the lower end of the drive shaft. The method according to claim 1 or 2, Towing tank test resistance dynamometer, characterized in that provided with a clamp for fixing the model ship to the body and the inspection unit for measuring the resistance. The method of claim 2, Left and right adjusting means is extended to the left and right of the body, the resistance dynamometer for towing tank test, characterized in that the measuring block is provided on each of the left and right adjustment means. The method of claim 4, wherein At least one of the measuring block is provided with a clamp for fixing the model ship, and the other one is a resistance dynamometer for a towing tank test, characterized in that it comprises an inspection unit for measuring the resistance. The method of claim 4, wherein Towing tank test resistance dynamometer, characterized in that each of the measuring block is provided with a pair of the clamp and the inspection unit.

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