Method for testing firing range of water cannon in overwater environment

Abstract

The invention discloses a water cannon range testing method in an overwater environment, and relates to the field of water cannon. The method for testing the range of the water cannon in the overwater environment comprises the following steps that a water cannon overwater testing platform is erected, and the water cannon is installed on the water cannon overwater testing platform to jet water flow for testing; establishing a two-dimensional coordinate system by taking an intersection point of a vertical line formed by an outlet of the water cannon and a preset horizontal plane as an original point; collecting motion track information of jet water flow of the water cannon in the two-dimensional coordinate system for fitting to establish a jet track fitting equation; and calculating the range of the water cannon in the shipment state according to the jet flow trajectory fitting equation and the water cannon test requirements. According to the water cannon range test method in the overwater environment, jet flow movement track data of a water cannon are obtained and fitted to obtain a jet flow track fitting equation, and then the water cannon range in a shipment state is calculated, so that the problem that a high-power water cannon is limited to land test conditions and cannot be subjected to range test under rated working conditions is solved. And the blank of a method for testing the free jet flow performance of domestic water cannon equipment in an overwater environment is filled.

Description

Technical Field

[0001] The present application relates to the field of water cannons, and specifically, to a method for testing the range of a water cannon in an aquatic environment. Background Art

[0002] In addition to being used as a means of firefighting on land and a weapon for riot control, water cannons are also widely used in various types of firefighting boats and official ships. Range and flow are the most important performance indicators. The flow test of water cannons is relatively simple, but the range test is relatively complicated. The test standard for water cannons stipulates the definition and test method of water cannon range: the water cannon range index test must be carried out on an open and flat site; under the condition of wind speed less than 2m / s, the water cannon elevation angle is 30±2°, the height of the water cannon outlet from the ground is not more than 3m, and the water cannon range is measured by spraying in the wind direction; when the water supply pressure at the water cannon inlet reaches the rated working pressure and stabilizes, use a stopwatch to measure the farthest point of the medium that is continuously sprinkled for no less than 10s, and the intersection of the plumb line at the water cannon outlet and the ground is taken as the origin (starting point). The horizontal distance from the farthest point to the origin is the water cannon range.

[0003] For water cannons with large flow and high lift, when the power of the water cannon is large (2400m 3 / h flow rate water cannon as an example, the water cannon pump power is above 1600kW), the driving power requirement for the water cannon pump is high, and sufficient water source and an open field with a diameter of not less than 300m are required for testing, and local environmental protection regulations must not be violated. Water cannon manufacturers generally do not have the land testing conditions for high-power water cannons, and water cannon range tests cannot be carried out during the factory test phase, and the laboratory environment and the actual ship operating environment are not completely consistent. Usually, when the water cannon performance test is carried out after installation on the actual ship, the height of the water cannon installed on the actual ship from the water surface is generally far more than 3m. Even if the target is arranged on the water surface to test the water cannon range, the test result will be larger than the actual range of the water cannon, affecting the research and development and use of the water cannon.

[0004] Therefore, a water cannon range testing method in an aquatic environment is needed to verify the water cannon range index. Summary of the invention

[0005] The purpose of this application is to provide a method for testing the range of a water cannon in an aquatic environment, which solves the problem that high-power water cannons are unable to carry out range tests under rated conditions due to limitations of onshore test conditions, and fills the gap in free jet performance testing methods for domestic water cannon equipment in an aquatic environment.

[0006] This application is implemented as follows:

[0007] The present application provides a method for testing the range of a water cannon in an aquatic environment, comprising the following steps:

[0008] Set up a water cannon water test platform, install the water cannon on the water cannon water test platform to spray water for testing;

[0009] A two-dimensional coordinate system is established with the intersection of the vertical line from the outlet of the water monitor and the preset horizontal plane as the origin;

[0010] Collect the motion trajectory information of the water jet of the water cannon in the two-dimensional coordinate system for fitting and establish the jet trajectory fitting equation;

[0011] The water cannon range in the loaded state is calculated according to the jet trajectory fitting equation and water cannon test requirements.

[0012] In some optional implementation schemes, when a water cannon is installed on a water cannon water test platform to spray water for testing, the height of the water cannon outlet from the water cannon water test platform is within 3 m.

[0013] In some optional implementation schemes, when the water cannon is installed on a water cannon water test platform to spray water for testing, the elevation angle of the water cannon is adjusted to 15° to 45°.

[0014] In some optional embodiments, when fitting the motion trajectory curve of the water jet of the water cannon in a two-dimensional coordinate system to establish the jet trajectory fitting equation, the jet trajectory fitting equation is established based on the coordinate fitting of at least three points of the motion trajectory of the water jet in the two-dimensional coordinate system.

[0015] In some optional embodiments, when fitting the motion trajectory curve of the water jet of the water cannon in a two-dimensional coordinate system to establish the jet trajectory fitting equation, the jet trajectory fitting equation is established based on the coordinate fitting of the jet water at the water cannon outlet, at the highest point and at the impact buoy target.

[0016] In some optional embodiments, when fitting the motion trajectory curve of the water jet of the water cannon in a two-dimensional coordinate system to establish the jet trajectory fitting equation, the jet trajectory fitting equation is established based on the coordinate fitting of the water jet at the water cannon outlet, the highest point, the impact buoy target and at least one other position.

[0017] In some optional embodiments, the coordinates (x C ,y C ) is calculated according to the following formula:

[0018]

[0019] In the formula, x C is the horizontal coordinate of the highest point of the jet, m; y Cis the ordinate of the highest point of the water jet, m; h is the height of the water cannon muzzle relative to the horizontal plane, m; v0 is the initial velocity of the water micro-group of the jet water, m / s; the elevation angle of the water cannon muzzle is 30°.

[0020] In some optional implementation schemes, when fitting the motion trajectory curve of the water jet of the water cannon in a two-dimensional coordinate system to establish the jet trajectory fitting equation, image recognition or laser ranging is used to obtain the coordinates of the motion trajectory of the water jet in the two-dimensional coordinate system.

[0021] The beneficial effects of the present application are as follows: the water cannon range test method provided by the present application comprises the following steps: setting up a water cannon water test platform, installing the water cannon on the water cannon water test platform to spray water for testing; establishing a two-dimensional coordinate system with the intersection of the vertical line of the water cannon outlet and the preset horizontal plane as the origin; collecting the motion trajectory information of the water cannon's sprayed water flow in the two-dimensional coordinate system for fitting to establish a jet trajectory fitting equation; calculating the water cannon range in the ship loading state according to the jet trajectory fitting equation and the water cannon test requirements. The water cannon range test method provided by the present application obtains the water cannon's sprayed water flow motion trajectory data for fitting to obtain the jet trajectory fitting equation, and then calculates the water cannon range in the ship loading state, which can solve the problem that high-power water cannons cannot carry out range tests under rated conditions due to the limitations of onshore test conditions, and fills the gap in the free jet performance test method of domestic water cannon equipment in the water environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A schematic diagram of a flow chart of a method for testing a water cannon range in an aquatic environment provided in an embodiment of the present application;

[0024] Figure 2 A schematic diagram of establishing an XY two-dimensional coordinate system using the intersection of a vertical line from the outlet of the water cannon and a preset horizontal plane as the origin in the water cannon range test method provided in Example 1 of the present application;

[0025] Figure 3 A schematic diagram of the forces acting on the water cannon in the air during the rising phase of the water jet in the water cannon range testing method provided in Example 1 of the present application in an aquatic environment;

[0026] Figure 4This is a schematic diagram of the fitting curve of the water cannon jet trajectory in the water cannon range testing method in an aquatic environment provided in Example 1 of the present application. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0028] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0029] The characteristics and performance of the water cannon range testing method in an aquatic environment of the present application are further described in detail below in conjunction with the embodiments.

[0030] like Figure 1 As shown, the embodiment of the present application provides a method for testing the range of a water cannon in an aquatic environment, comprising the following steps:

[0031] Step 1: Set up a water cannon water test platform according to the water cannon range test method and requirements, install the water cannon on the water cannon water test platform to spray water for testing, and set a buoy target on the water surface so that the water sprayed by the water cannon shoots the buoy target; wherein, optionally, the height of the water cannon outlet from the ground of the water cannon water test platform is within 3m. Optionally, the elevation angle of the water cannon is adjusted to 15°~45°. Optionally, the elevation angle of the water cannon is adjusted to 30°. Optionally, the water cannon water test platform can be set up on the river surface, river surface, lake surface and sea surface, and the water surface is the river surface, river surface, lake surface and sea surface respectively. The horizontal plane described in this embodiment is a horizontal plane or sea level.

[0032] Step 2: Figure 2 As shown, an XY two-dimensional coordinate system is established with the intersection of a vertical line from the outlet of the water monitor and a preset horizontal plane as the origin, the firing direction of the water monitor is the positive direction of the X direction, the vertical upward direction is the positive direction of the Y direction, and the water monitor fires water flow in the direction of the wind;

[0033] Step 3, collecting the motion trajectory information of the water jet of the water cannon in the two-dimensional coordinate system, and fitting the coordinates of at least three points on the motion trajectory of the water jet in the two-dimensional coordinate system to establish a jet trajectory fitting equation;

[0034] Since the jet water flow launched by the water cannon is easy to diverge in the second half of the motion trajectory, that is, the water column is broken, making its trajectory simulation very difficult, therefore, only the trajectory characteristics of the water cannon jet in the rising stage are analyzed, the water micro-clusters in the jet water flow launched by the water cannon are taken as the research objects to analyze the force and movement, and the jet trajectory fitting equation in the rising stage of the jet water flow is established.

[0035] Optionally, the water cannon jet trajectory curve is a parabola-like curve, and a quadratic polynomial curve is used for fitting; the water cannon muzzle is used as the trajectory starting point, the buoy target position is used as the trajectory end point, and the jet trajectory fitting equation is established using ORIGIN software in combination with the position information of typical points in the middle of the water cannon jet, such as the highest point. Optionally, the jet trajectory fitting equation is established based on the coordinate fitting of the jet water flow at the water cannon outlet, at the highest point, and at the impact buoy target. Optionally, the jet trajectory fitting equation is established based on the coordinate fitting of the jet water flow at the water cannon outlet, the highest point, the impact buoy target, and at least one other position.

[0036] When the elevation angle of the water cannon muzzle is 30°, the coordinates of the highest point of the jet (x C ,y C ) is calculated according to the following formula:

[0037]

[0038] In the formula, x C is the horizontal coordinate of the highest point of the jet, m; y C is the ordinate of the highest point of the water jet, m; h is the height of the water cannon muzzle relative to the horizontal plane, m; v0 is the initial velocity of the water micro-group of the water jet, m / s.

[0039] Optionally, when fitting the motion trajectory curve of the water jet of the water cannon in the two-dimensional coordinate system to establish the jet trajectory fitting equation, image recognition or laser ranging is used to obtain the coordinates of the motion trajectory of the water jet in the two-dimensional coordinate system.

[0040] Step 4: Calculate the water cannon range in the loaded state according to the jet trajectory fitting equation and the water cannon test requirements. According to the water cannon range test requirements and the Y coordinate information of the water cannon water test platform, the X coordinate information of the corresponding point can be obtained, which is the water cannon range.

[0041] The water cannon range test method in an aquatic environment provided in the embodiment of the present application is carried out by setting up a water cannon aquatic test platform and installing the water cannon on the water cannon aquatic test platform to spray water for testing. After obtaining the position information of several points on the water cannon jet trajectory, the jet trajectory curve is fitted to establish a jet trajectory fitting equation. The actual range of the water cannon can be calculated based on the jet trajectory fitting equation and the actual ship test results, thereby meeting the range test requirements of water cannons installed on actual ships in an aquatic environment, solving the problem that high-power water cannons are unable to carry out range tests under rated conditions due to limitations of onshore test conditions, and filling the gap in free jet performance test methods for domestic water cannon equipment in an aquatic environment.

[0042] Example 1

[0043] like Figure 1 As shown, the embodiment of the present application provides a method for testing the range of a water cannon in an aquatic environment, comprising the following steps:

[0044] Step 1: Refer to the water cannon range test conditions in GB19156-2003 General Technical Conditions for Fire Monitors, build a water cannon water test platform, install the water cannon on the water cannon water test platform to spray water for testing, and set a buoy target on the water surface so that the water cannon sprays the water to shoot at the buoy target;

[0045] Step 2: Figure 2 The intersection of the vertical line and the horizontal plane at the water cannon outlet is used as the origin to establish an XY two-dimensional coordinate system. The direction along which the water cannon is ejected is the positive X direction, and the vertical upward direction is the positive Y direction. The force and motion of the water micro-groups in the water flow ejected by the water cannon during the rising stage are analyzed. The air movement and force of the water micro-groups are shown in the figure. Figure 3 shown.

[0046] Step 3, collecting the motion trajectory information of the water jet of the water cannon in the two-dimensional coordinate system, and fitting the coordinates of four points on the motion trajectory of the water jet in the two-dimensional coordinate system to establish a jet trajectory fitting equation;

[0047] Without considering the wind speed, the water jet micro-group is only affected by gravity and air resistance (without considering buoyancy and Coriolis force); when the speed of the object is much lower than the speed of the low-speed projectile, the air resistance of the object can be approximately proportional to the speed. According to Newton's second law, the motion equations of a unit mass of water jet micro-group in the x and y directions are as follows:

[0048]

[0049] Where k is the air resistance coefficient, which is taken as 0.02 according to relevant literature. Assume that the muzzle height of the water cannon is h, the initial velocity of the water micro-group is v0, the elevation angle is 30°, and g = 9.8m 2 / s Solving the above differential equations, we can get:

[0050] x=43.30v0(1-e -0.02t );

[0051] y=(24500+25v0)(1-e -0.02t )-490t+h;

[0052] v x =0.866v0e -0.02t ;

[0053] v y =(490+0.5v0)e -0.02t -490;

[0054] When the water micro-group rises to the highest point C, v y =0, the coordinate information of point C can be obtained as follows:

[0055]

[0056] The intersection of the vertical line from the cannon outlet and the horizontal plane is taken as the origin of the coordinate system. The coordinates of the cannon outlet at point A and the buoy target at point E are (0, h) and (L1, h1), respectively. The coordinates of point D are (L, h0), where L is the range of the cannon. The fitting curve equation of the cannon jet trajectory is established based on the coordinate information of the points along the cannon jet trajectory. The coordinate value of point D is obtained to obtain the cannon range.

[0057] With flow rate of 2400m 3 / h water cannon as an example, the diameter of the water cannon mouth is 125mm, refer to the water cannon range test conditions in GB19156-2003 "General Technical Conditions for Fire Cannons", and build a water cannon range marine environment test platform: the height of the water cannon outlet from the water cannon base installation horizontal plane is 2.5m, the water cannon elevation angle is adjusted to 30°, and the height of the water cannon base installation horizontal plane from the horizontal plane is h0=10m; a buoy target is set on the sea surface with a height h1 of 1m. The farthest buoy target position hit by the water cannon is 240m away from the water cannon mouth; a flow meter and a pressure gauge are set at the water inlet of the water cannon. After the water inlet of the water cannon reaches the rated pressure, the water cannon flow is measured to be 2410m 3 / h, the water flow velocity at the water monitor outlet is calculated to be v0=54.55m / s.

[0058] Based on the above conditions, the coordinates of points A, B, and E are A (0, 12.5), C (124.55, 49.10), and E (240, 1) respectively. To improve the accuracy of the trajectory fitting curve, the coordinates of point B (46.77, 34.64) when the water flow movement time t = 1s is added as an auxiliary point of the fitting curve. Based on the coordinate information of the above four points, the ORIGIN software is used to establish the water cannon jet trajectory fitting curve, as shown in Figure 1. Figure 4 As shown. The fitting equation of the water cannon jet trajectory is y = -0.003x 2 +0.656x+11.782. According to y c =h0=10m, and the actual range of the water monitor is L=xc=226m.

[0059] It should be noted that the coordinate values ​​of points B and C are calculated and have certain errors. The actual coordinate information of other water cannon trajectory points can be obtained by using image recognition or laser ranging technology. The actual measurement results should be used to fit the water cannon trajectory curve.

[0060] The embodiments described above are part of the embodiments of the present application, rather than all of the embodiments. The detailed description of the embodiments of the present application is not intended to limit the scope of the present application for protection, but merely represents the selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

Claims

1. A method for testing the range of a water cannon in an aquatic environment, characterized in that: The following steps are involved: Setting up a water cannon water test platform, installing a water cannon on the water cannon water test platform and spraying water to conduct a test; A two-dimensional coordinate system is established with the intersection of a vertical line from the outlet of the water monitor and a preset horizontal plane as the origin; Collecting the motion trajectory information of the water jet of the water cannon in the two-dimensional coordinate system for fitting and establishing a jet trajectory fitting equation; The water cannon range in the loaded state is calculated according to the jet trajectory fitting equation and the water cannon test requirements.

2. The method for testing the range of a water cannon in an aquatic environment according to claim 1, characterized in that: When the water cannon is installed on the water cannon water test platform to spray water for testing, the height of the water cannon outlet from the ground of the water cannon water test platform is within 3m.

3. The method for testing the range of a water cannon in an aquatic environment according to claim 1, characterized in that: When the water cannon is installed on the water cannon water test platform to spray water for testing, the elevation angle of the water cannon is adjusted to 15° to 45°.

4. The method for testing the range of a water cannon in an aquatic environment according to claim 1, characterized in that: When fitting the motion trajectory curve of the jet water flow of the water cannon in the two-dimensional coordinate system to establish the jet trajectory fitting equation, the jet trajectory fitting equation is established based on the coordinate fitting of at least three points of the motion trajectory of the jet water flow in the two-dimensional coordinate system.

5. The method for testing the range of a water cannon in an aquatic environment according to claim 1, characterized in that: When fitting the motion trajectory curve of the jet water flow of the water cannon in the two-dimensional coordinate system to establish the jet trajectory fitting equation, the jet trajectory fitting equation is established based on the coordinate fitting of the jet water flow at the water cannon outlet, at the highest point and at the impact buoy target.

6. The method for testing the range of a water cannon in an aquatic environment according to claim 1, characterized in that: When fitting the motion trajectory curve of the jet water flow of the water cannon in the two-dimensional coordinate system to establish the jet trajectory fitting equation, the jet trajectory fitting equation is established based on the coordinate fitting of the jet water flow at the water cannon outlet, the highest point, the impact buoy target and at least one other position.

7. The method for testing the range of a water cannon in an aquatic environment according to claim 6, characterized in that: The coordinates (x C ,y C ) is calculated according to the following formula: In the formula, x C is the horizontal coordinate of the highest point of the water jet, m; y C is the ordinate of the highest point of the water jet, m; h is the height of the water cannon muzzle relative to the horizontal plane, m; v0 is the initial velocity of the water particles of the water jet, m / s; the elevation angle of the water cannon muzzle is 30°.

8. The method for testing the range of a water cannon in an aquatic environment according to claim 1, characterized in that: When fitting the motion trajectory curve of the jet water flow of the water cannon in the two-dimensional coordinate system to establish the jet trajectory fitting equation, image recognition or laser ranging is used to obtain the coordinates of the motion trajectory of the jet water flow in the two-dimensional coordinate system.

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