JP3144142B2 - Arc heating wind tunnel device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arc heating wind tunnel apparatus.

[0002]

2. Description of the Related Art FIGS. 4 and 5 show an example of an arc heating wind tunnel apparatus in which a high temperature plasma stream is blown against a specimen to perform a heat test (heat resistance test, erosion test, etc.) on the specimen. As shown, an arc heater 3 and an exhaust cooler 4 are arranged to face each other via a vacuum tank 2 in which a test piece 1 is installed. In the arc heater 3, a gas is supplied from a gas supply device 5 as appropriate. A working gas 6 is introduced between a cathode 8a and an anode 8b respectively connected to a DC power supply 7 to form a high-temperature (4000 to 10000 ° C.) plasma gas flow 9 by arc discharge. In the exhaust cooler 4, one side is cut out alternately in the jet direction of the plasma gas flow 9 and is continuously connected at appropriate intervals. Together The plurality of baffle plates 12 which set is formed with an exhaust passage 13, and is able to cool directing the plasma stream 9 to the exhaust air flow path 13.

Further, an exhaust device 16 comprising a booster pump 14 and a rotary pump 15 is connected to the rear of the exhaust cooler 4, and the booster pump 14 is turned on before the arc heater 3 injects the plasma stream 9.
And the rotary pump 15 cooperate to evacuate the inside of the apparatus. When the evacuation is completed, the rotary pump 15 is switched to an independent operation, and the plasma air flow 9 cooled by the exhaust cooler 4 is raised to atmospheric pressure. So that it can be exhausted.

Further, a cooling water passage 17 is formed in a portion where the heat load of the arc heater 3 is large, and the vacuum tank 2 and the exhaust cooler 4 have a water cooling jacket structure, and are arranged at required places. Cooling water 1 from cooling device 18
9 is circulated and supplied.

[0005]

However, when performing a thermal test with the above-described conventional arc-heating wind tunnel apparatus, depending on the shape of the test piece 1 disposed in the vacuum tank 2, the test piece 1 may be blown onto the test piece 1. The barrel flow of the plasma airflow 9 spreads over the diameter of the intake 20 of the exhaust cooler 4,
In some cases, the entire amount of the plasma airflow cannot be taken into the exhaust cooler 4 satisfactorily, and the inside of the vacuum tank 2 becomes overheated due to the high-temperature plasma airflow 9 remaining in the vacuum tank 2, causing burnout of internal equipment and the like. There is a possibility that the adverse effects of the above may be caused.

In the conventional structure, when the plasma gas flow 9 spreads beyond the diameter of the intake port 20 of the exhaust cooler 4, the pressure loss of the plasma gas flow 9 is large, and the pressure of the plasma gas flow 9 is increased to atmospheric pressure. There is also a problem that the capacity of the rotary pump 15 (exhaust pump) used when exhausting air must be increased to compensate for the pressure loss.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides an arc heating wind tunnel apparatus capable of satisfactorily taking in the entire amount of a plasma air flow injected into a vacuum tank into an exhaust cooler with a small pressure loss. It is intended to be.

[0008]

According to a first aspect of the present invention, there is provided an arc heater for injecting a high-temperature plasma airflow and an exhaust cooler for taking in the plasma airflow and cooling the same. In an arc heating wind tunnel device arranged to face through an installed vacuum tank, a bell mouth that opens toward the arc heater is disposed at a plasma air flow intake of the exhaust cooler. The invention according to claim 2 of the present invention is characterized in that a throat portion is formed at an intermediate portion in the axial direction of the bell mouth, and the invention according to claim 3 of the present invention is directed to a bell mouth. The cooling water pipe is integrally provided on the outer peripheral surface of the bellows, and the invention according to claim 4 of the present invention is characterized in that the bell mouth has a water cooling jacket structure.

[0009]

Therefore, according to the first aspect of the present invention, even if the barrel flow of the plasma gas blown from the arc heater to the test specimen spreads beyond the diameter of the intake of the exhaust cooler, the plasma flow is maintained. Since the whole amount is well taken into the exhaust cooler by the bell mouth, a part of the plasma gas flow does not remain in the vacuum tank, and the inside of the vacuum tank is prevented from being overheated. The pressure loss is reduced because the bellmouth smoothly takes in the exhaust cooler without disturbing the flow.

According to the second aspect of the present invention, an ejector effect is generated by the flow velocity energy when the plasma airflow passes through the throat portion of the bell mouth, and the plasma airflow injected into the vacuum tank is activated. As a result, the plasma airflow does not diffuse to the region outside the bellmouth, and the entire plasma airflow can be more reliably taken in.

Further, since the lean air in the vacuum tank is simultaneously sucked from the periphery of the plasma air flow, the flow of the lean air flows in a film form between the inner peripheral surface of the bell mouth and the plasma air flow, so that the bell mouth is formed. The direct contact between the inner peripheral surface of the bell mouth and the plasma airflow is prevented, the heat load on the bellmouth is reduced, and the degree of vacuum in the vacuum tank is further increased.

Further, according to the third aspect of the present invention, the bell mouth is cooled by supplying cooling water to the cooling water pipe from a vacuum tank, a water cooling jacket of an exhaust cooler, or another system. Heat resistance can be increased.

According to the invention of claim 4 of the present invention, the cooling efficiency of the bellmouth is increased by supplying cooling water to the inside of the bellmouth having the water-cooled jacket structure, and the heat resistance is further improved. It becomes possible.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention, and portions denoted by the same reference numerals as those in FIGS. 4 and 5 represent the same components.

In the arc heating wind tunnel device 21 having substantially the same configuration as the above-described arc heating wind tunnel device of FIGS. 4 and 5, an opening is directed to the arc heater 3 at the intake 20 of the plasma stream 9 of the exhaust cooler 4. The bellmouth 22 is provided.

The bell mouth 22 is made of a material having a high thermal conductivity such as copper. A cooling water pipe 23 is spirally wound around the outer surface of the bell mouth 22 and integrally attached thereto. The cooling water 19 can be supplied from the water cooling jacket of the tank 2, the exhaust cooler 4, or another system.

When a thermal test is performed using the arc heating wind tunnel device 21, the barrel flow of the plasma gas flow 9 blown from the arc heater 3 to the test piece 1 causes the diameter of the inlet 20 of the exhaust cooler 4 to be reduced. Even if the plasma air flow 9 spreads as described above, the entire amount of the plasma air flow 9 is taken into the exhaust cooler 4 by the bell mouth 22 satisfactorily, so that a part of the plasma air flow 9 does not remain in the vacuum tank 2 and the inside of the vacuum tank 2 Is prevented from being overheated.

The plasma flow 9 is a bell mouth 2
The pressure loss is reduced because the gas is smoothly taken into the exhaust cooler 4 without being disturbed by the flow.

Therefore, according to the above embodiment, the vacuum tank 2
Since the entire amount of the plasma gas flow 9 injected into the inside can be taken into the exhaust cooler 4 satisfactorily, the vacuum tank 2 can be prevented from being overheated by the remaining plasma gas flow 9, and the vacuum tank 2 can be prevented from being overheated. Harmful effects such as burning of the internal equipment can be prevented.

Further, since the bell mouth 22 can smoothly take the plasma gas flow 9 into the exhaust cooler 4 without disturbing the flow, the pressure loss of the plasma gas flow 9 can be significantly reduced as compared with the conventional case, and the plasma gas flow 9 can be reduced. The capacity of the rotary pump 15 (exhaust pump) used for evacuation by raising the pressure of 9 to atmospheric pressure can be greatly reduced.

FIG. 2 shows another embodiment of the present invention.
The throat portion 24 is formed at an intermediate portion of the bell mouth 22 in the axial direction.

In the case of this embodiment, an ejector effect is generated by the flow velocity energy when the plasma gas flow 9 passes through the throat portion 24 of the bell mouth 22, and the vacuum tank 2
The plasma air flow 9 injected into the inside actively the bell mouth 2
2, the plasma airflow 9 is generated by the bell mouth 22.
The plasma air flow 9 is no longer diffused to the outer region, so that the entire amount of the plasma air flow 9 can be more reliably taken in. Further, the lean air 25 in the vacuum tank 2 is also sucked from the periphery of the plasma air flow 9 at the same time. 25 flows in a film form between the inner peripheral surface of the bellmouth 22 and the plasma airflow 9, thereby preventing direct contact between the inner peripheral surface of the bellmouth 22 and the plasma airflow 9, and
Is reduced, and the degree of vacuum in the vacuum tank 2 is further increased.

In the illustrated example, a cooling system in which a cooling water pipe 23 is integrally provided on the outer peripheral surface of the bell mouth 22 is adopted. However, as shown in FIG. 3, if the bell mouth 22 has a water cooling jacket structure. By circulating and supplying the cooling water 19 from the vacuum tank 2 or the water cooling jacket of the exhaust cooler 4 into the water cooling jacket 26 of the bell mouth 22, the bell mouth 22 can be directly cooled to further improve the heat resistance. .

It should be noted that the arc-heating wind tunnel device of the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0026]

According to the above-described arc-heating wind tunnel device of the present invention, the following various excellent effects can be obtained.

(I) According to the first aspect of the present invention, the entire amount of the plasma gas flow injected into the vacuum tank can be taken into the exhaust cooler satisfactorily, so that the inside of the vacuum tank remains. It is possible to prevent the overheating state due to the plasma airflow, and to prevent the internal devices of the vacuum tank from being burned out.

(II) Since the bell mouth can be smoothly taken into the exhaust cooler without disturbing the flow of the plasma air flow, the pressure loss of the plasma air flow can be significantly reduced as compared with the conventional art, and the plasma air flow can be reduced to the atmospheric pressure. It is possible to greatly reduce the capacity of an exhaust pump used when exhausting by elevating the pressure.

(III) According to the second aspect of the present invention, the plasma airflow injected into the vacuum tank is reduced by the ejector effect of the flow velocity energy when the plasma airflow passes through the throat portion of the bell mouth. Active suction into the bell mouth allows the entire plasma airflow to be taken in more reliably, and at the same time allows the air in the vacuum tank from the periphery of the plasma airflow to be sucked in at the same time. The thin air flowing in the form of a film between the peripheral surface and the plasma airflow prevents direct contact between the inner peripheral surface of the bellmouth and the plasma airflow, thereby reducing the heat load of the bellmouth and a vacuum tank. The degree of vacuum inside can be further increased.

(IV) In the invention according to claim 3 of the present invention, the bell mouth is cooled by supplying cooling water to the cooling water pipe from a vacuum tank, a water cooling jacket of an exhaust cooler, or another system. Can be improved in heat resistance.

(V) In the invention according to claim 4 of the present invention, the cooling efficiency of the bellmouth is increased by supplying cooling water to the inside of the bellmouth having a water-cooled jacket structure, and the heat resistance is further improved. Can be.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing another embodiment of the present invention.

FIG. 3 is a sectional view showing still another embodiment of the present invention.

FIG. 4 is a sectional view showing a conventional example.

FIG. 5 is an enlarged sectional view showing the arc heater of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Specimen 2 Vacuum tank 3 Arc heater 4 Exhaust cooler 9 Plasma airflow 20 Intake 21 Arc heating wind tunnel device 22 Bell mouth 23 Cooling water pipe 24 Throat part 26 Water cooling jacket

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-249002 (JP, A) JP-A-5-142104 (JP, A) JP-A-5-288664 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) G01M 9/02

Claims (4)

(57) [Claims] 1. An arc heating wind tunnel device in which an arc heater for injecting a high-temperature plasma airflow and an exhaust cooler for taking in and cooling the plasma airflow are arranged to face each other via a vacuum tank in which a specimen is installed. An arc heating wind tunnel device, wherein a bell mouth that opens toward the arc heater is disposed at a plasma air flow inlet of the exhaust cooler. 2. The arc heating wind tunnel device according to claim 1, wherein a throat portion is formed at an intermediate portion of the bell mouth in the axial center direction. 3. The arc heating wind tunnel device according to claim 1, wherein a cooling water pipe is integrally provided on an outer peripheral surface of the bell mouth. 4. The arc heating wind tunnel device according to claim 1, wherein the bell mouth has a water cooling jacket structure.