CN103940729A - Liquid impact test piece capable of generating jet leading edge and test method - Google Patents

Abstract

The invention provides a liquid impact test piece capable of generating a jet leading edge. The liquid impact test piece comprises a to-be-tested material main body and a shielding screen, wherein a Z-shaped structure is formed by two adjacent surfaces on the shielding screen and one surface of the to-be-tested material main body. The invention also provides a liquid impact test piece capable of generating a jet leading edge. The jet leading edge is generated by using the jet through the edge of the shielding screen, so as to obtain the effect that the jet leading edge impacts the surface of the to-be-tested material main body. Erosion effects of liquid-solid impact at different angles are obtained by adjusting the mounting angle of the test piece. Compared with the traditional test piece, the effect of imitating the impact of the jet leading edge accords with the reality, the test result can disclose the mechanism of destroy generated by liquid-solid high-speed impact, and the liquid impact test piece has the characteristics of being simple in structure and easy to carry out.

Description

A kind of liquid knockout testpieces and test method that can produce jet leading edge

Technical field

The present invention relates to a kind of testpieces and test method for test material opposing liquid knockout effect with new model, belong to material opposing liquid knockout performance test technical field.

Background technology

Liquid at high speed is clashed into solid material surface, will produce erosion action to solid material.The low-pressure final stage movable vane of steam turbine is operated in wet-steam region, and the moisture film of stator blade surface condensation is torn into after secondary water droplet by air-flow, may and movable vane between produce the high-speed impact of 300～700m/s, to the strong water erosion effect of movable vane material production.Similar with it, aircraft is when at a high speed through cloud layer, rain belt, and surfacing is easily subject to droplets impact its.Relative velocity high between water droplet and aircraft can cause the deformation and failure of the member such as view window, radome, thereby causes the inefficacy of instrument even to threaten flight safety.In engineering, by setting up whirling test stand, study dynamic behavior, the micromechanism of damage of material and the effect of material opposing liquid knockout of liquid-solid high-speed impact process medium fluid and material by the mode of test.

In prior art, the effect of resisting liquid knockout for material, often by repeatedly liquid-solid impact test device of rotation test part, adopts flat board, cylinder or Airfoil Testing part.When carry out the anti-erosion effect of test material with impinging jet, this class testpieces cannot be simulated the leading edge of jet or the impact effects of drop.

Summary of the invention

The technical problem to be solved in the present invention is to provide one can be arranged on rotation test part repeatedly on liquid-solid impact test device, testpieces and the test method of the repeated impact effect of simulation jet leading edge to material same position.

In order to solve the problems of the technologies described above, technical scheme of the present invention is to provide a kind of liquid knockout testpieces that can produce jet leading edge, it is characterized in that: formed with blocking to shield by body of material to be tested, block a surface formation Z-shaped structure of upper two the adjacent surfaces of screen and body of material to be tested.

Preferably, described body of material to be tested bottom is provided with mounting hole.

Preferably, described in, blocking screen adopts the material identical or different with body of material to be tested to make.

Preferably, described in, blocking screen adopts the pottery of resistance to corroded by liquid or stellite material to make.

The present invention also provides a kind of liquid knockout test method that can produce jet leading edge, it is characterized in that: adopt the above-mentioned liquid knockout testpieces that can produce jet leading edge, the method is made up of following 3 steps:

Step 1: testpieces is arranged on to rotation test part repeatedly on liquid-solid impact test device;

Step 2: the liquid-solid projected angle of impact needing according to test, the setting angle of adjustment testpieces;

Step 3: on-test, stable state jet impulse is on the surface of blocking screen of testpieces; Along with testpieces moves on, to pass by while blocking the edge of screen when jet-core region, jet leading edge regenerates and hits the surface of body of material to be tested, and the surface of jet leading edge and body of material to be tested bumps.

Preferably, in described step 1, testpieces is arranged on rotation test part repeatedly on liquid-solid impact test device by the mounting hole of body of material to be tested bottom.

Preferably, in described step 2, the liquid-solid projected angle of impact needing according to test, the method for adjusting the setting angle of testpieces is:

If testpieces is with absolute velocity u motion, jet is with absolute velocity c motion, and the angle of effluxvelocity c and testpieces reverse movement direction is α, according to the cosine law, calculates the relative velocity w of jet and testpieces:

$w=\sqrt{u^2+v^2-2\mathrm{uv}\cos (180-\mathrm{\α})}$

The angle β of the relative velocity w of jet and testpieces and testpieces reverse movement direction is tried to achieve by following formula:

$\mathrm{\β}=\arcsin \left(\frac{c\cos (90-\mathrm{\α})}{w}\right)$

If the liquid-solid projected angle of impact that test needs is θ, setting angle γ=180 of testpieces °-β-θ.

The liquid knockout testpieces that can produce jet leading edge provided by the invention, has the screen of blocking structure, and blocking screen can make entirety or Split type structure with body of material to be tested; Testpieces utilizes jet to produce jet leading edge by blocking the edge of screen, obtains jet leading edge and clashes into water hammer power and the lateral shear power that body of material to be tested surface produces, and reaches the effect of accelerating liquid knockout test; By adjusting the setting angle of testpieces, obtain the erosion effect of the liquid knockout solid of different angles.

Compare traditional flat board, cylinder or Airfoil Testing part, the effect that testpieces imitation jet leading edge provided by the invention is clashed into is realistic, test findings can disclose liquid-solid high-speed impact and produce the mechanism of destroying, and there is feature simple in structure, easy to implement, can be widely used in the material properties test of liquid-solid high-speed impact and the research of liquid knockout erosion mechanism.

Brief description of the drawings

Fig. 1 is the liquid knockout testpieces schematic diagram that can produce jet leading edge provided by the invention;

Fig. 2 is the schematic diagram that impinging jet blocks screen;

Fig. 3 is that jet leading edge regenerates, and hits the schematic diagram on body of material to be tested surface;

Fig. 4 is the schematic diagram that jet leading edge is clashed into body of material to be tested surface;

Fig. 5 is the schematic diagram on stable state impinging jet body of material to be tested surface.

Embodiment

For the present invention is become apparent, hereby with a preferred embodiment, and coordinate accompanying drawing to be described in detail below.

Fig. 1 is the liquid knockout testpieces schematic diagram that can produce jet leading edge provided by the invention, and described testpieces is certain type Steel material testpieces to be tested, by body of material A to be tested and block screen C jointly form.Blocking screen C forms by a surface overlaying stellite in Steel material main body to be tested, the described surface of blocking upper two the adjacent surfaces of screen C and body of material A to be tested forms Z-shaped structure, the intermediate connection of zigzag is not by impinging jet, if three lines of Z-shaped might not straight line certainly.For the ease of clamping, body of material A to be tested has designed bottom two mounting hole I.

Can produce the liquid knockout test method of jet leading edge, comprise following 3 steps:

Step 1: by two mounting hole L, the liquid knockout testpieces that can produce jet leading edge provided by the invention is arranged on to rotation test part repeatedly on liquid-solid impact test device, rotation test part repeatedly liquid-solid impact test device manufactures and designs according to U.S. material association criterion G73-10.

Step 2: with absolute velocity u=342m/s motion, jet B is with absolute velocity c=322m/s motion by testpieces, and the angle of effluxvelocity c and testpieces reverse movement direction is α=51 °.In the position of initial time testpieces and jet as shown in Figure 2.According to the cosine law, the speed that can calculate the relative testpieces of jet is

$w=\sqrt{u^2+v^2-2\mathrm{uv}\cos (180-\mathrm{\α})}=599.4m/s$

The angle β of the relative velocity w of jet and testpieces and testpieces reverse movement direction is tried to achieve by following formula

Can be according to the relative velocity w of the jet calculating and testpieces, and deflection β, adjust the setting angle γ of testpieces, thereby produce different liquid-solid projected angle of impact θ.In the present embodiment, liquid-solid projected angle of impact θ=90 °, established angle γ=90 of testpieces °-β=65.3 °.

Step 3: at the initial time shown in Fig. 2, stable state jet B impacts on the surperficial D that blocks screen C being made up of stellite of testpieces.Along with testpieces moves on, as shown in Figure 3, pass by while blocking the edge E of described adjacent two surperficial junctions of screen C when jet-core region line, jet leading edge G regenerates and hits the surperficial F of body of material to be tested within very short time.The surperficial F of jet leading edge and body of material to be tested bumps, and as shown in Figure 4, jet clashes at the surperficial F of H position and body of material to be tested.Within the initial very short time, stable state jet B and body of material to be tested surface F clash into the liquid shock wave producing and are attached to body of material to be tested surface, now do not have the water of side direction to spill, to produce water hammer power and lateral shear power, thereby realize with hydrofluidic and simulate drop shock solid surface, accelerated the test effect that liquid corrodes solid surface.As shown in Figure 5, after having passed through the shock on jet leading edge and body of material to be tested surface, stable state jet impulse is proceeded on jet and body of material to be tested surface, no longer has the impact effects of jet leading edge.

Compare traditional flat board, cylinder or Airfoil Testing part, the effect that testpieces imitation jet leading edge provided by the invention is clashed into is realistic, compare the leading edge impulsive force that traditional test specimen can produce 3 times, there is the function of accelerating liquid knockout erosion test, test findings can disclose liquid-solid high-speed impact and produce the mechanism of destroying, and has engineering using value.

This testpieces is simple in structure, easy to implement, can be widely used in the material properties test of liquid-solid high-speed impact and the research of liquid knockout erosion mechanism.

Claims (7)

1. one kind can produce the liquid knockout testpieces of jet leading edge, it is characterized in that: by body of material to be tested (A) with block screen (C) and form, block a surface formation Z-shaped structure of upper two the adjacent surfaces of screen (C) and body of material to be tested (A).

2. a kind of liquid knockout testpieces that can produce jet leading edge as claimed in claim 1, is characterized in that: described body of material to be tested (A) bottom is provided with mounting hole (I).

3. a kind of liquid knockout testpieces that can produce jet leading edge as claimed in claim 1 or 2, is characterized in that: described in block screen (C) and adopt with the identical or different material of body of material to be tested (A) and make.

4. a kind of liquid knockout testpieces that can produce jet leading edge as claimed in claim 1 or 2, is characterized in that: described in block screen (C) and adopt the pottery of resistance to corroded by liquid or stellite material to make.

5. the liquid knockout test method that can produce jet leading edge, is characterized in that: adopt the liquid knockout testpieces that can produce jet leading edge claimed in claim 1, the method is made up of following 3 steps:

Step 1: the liquid knockout testpieces that can produce jet leading edge claimed in claim 1 is arranged on to rotation test part repeatedly on liquid-solid impact test device;

Step 2: the liquid-solid projected angle of impact needing according to test, the setting angle of adjustment testpieces;

Step 3: on-test, stable state jet (B) impacts on the surface of blocking screen (C) of testpieces (D); Along with testpieces moves on, when passing by while blocking the edge (E) of screen (C) in jet-core region, jet leading edge (G) regenerates and hits the surface (F) of body of material to be tested, and jet leading edge (G) bumps with the surface (F) of body of material to be tested.

6. a kind of liquid knockout test method that can produce jet leading edge as claimed in claim 5, it is characterized in that: in described step 1, testpieces is arranged on rotation test part repeatedly on liquid-solid impact test device by the mounting hole (I) of body of material to be tested (A) bottom.

7. a kind of liquid knockout test method that can produce jet leading edge as claimed in claim 5, is characterized in that: in described step 2, and the liquid-solid projected angle of impact needing according to test, the method for adjusting the setting angle of testpieces is:

If testpieces is with absolute velocity u motion, jet is with absolute velocity c motion, and the angle of effluxvelocity c and testpieces reverse movement direction is α, according to the cosine law, calculates the relative velocity W of jet and testpieces:

$w=\sqrt{u^2+v^2-2\mathrm{uv}\cos (180-\mathrm{\α})}$

The angle β of the relative velocity w of jet and testpieces and testpieces reverse movement direction is tried to achieve by following formula:

$\mathrm{\β}=\arcsin \left(\frac{c\cos (90-\mathrm{\α})}{w}\right)$

If the liquid-solid projected angle of impact that test needs is θ, setting angle γ=180 of testpieces °-β-θ.