CN113390604B

CN113390604B - One-dimensional hot wire probe suitable for high-speed flow field measurement

Info

Publication number: CN113390604B
Application number: CN202110804798.5A
Authority: CN
Inventors: 朱博; 王宁; 陈钦
Original assignee: Equipment Design and Testing Technology Research Institute of China Aerodynamics Research and Development Center
Current assignee: Equipment Design and Testing Technology Research Institute of China Aerodynamics Research and Development Center
Priority date: 2021-07-16
Filing date: 2021-07-16
Publication date: 2023-03-03
Anticipated expiration: 2041-07-16
Also published as: CN113390604A

Abstract

The invention discloses a method for manufacturing a one-dimensional hot wire probe suitable for high-speed flow field measurement. The diameter d of the arc-shaped hot wire, the chord length L is more than or equal to 200d, and the chord height is =0.2L; the whole plating layer at the front end of the probe adopts platinum or gold. The invention adopts the arc-shaped hot wire structure, determines the chord height of the arc-shaped hot wire according to the test and calculation results, adopts the integral coating for fixing and preventing the front end from high-temperature oxidation, obviously prolongs the service life of the probe under the impact of high pneumatic load and flow field particles, simultaneously reduces the vibration of the hot wire in the flow field, reduces false signals such as the strain effect of the hot wire and the like, and improves the test precision.

Description

One-dimensional hot wire probe suitable for high-speed flow field measurement

Technical Field

The invention belongs to the technical field of flow field testing, and particularly relates to a method for manufacturing a one-dimensional hot wire probe suitable for high-speed flow field measurement.

Background

The hot wire is a common device in the technical field of flow field testing, is usually used for measuring fluid speed and turbulence, is the most main means for measuring the turbulence of a wind tunnel flow field, is especially widely applied to a low-speed flow field, and is a standard method for measuring the turbulence of the low-speed wind tunnel flow field.

The conventional one-dimensional probe hot wire is designed into a tight linear state between two end points so as to avoid the shaking of the hot wire caused by vortex-induced vibration in a flow field, but in a high-speed flow field, because the pneumatic load of fluid is large and even the cleanliness of the fluid is not high enough, high-speed particles in the fluid hit the hot wire, tensile resistance strain is generated on the tight hot wire, and the sensitive parameters of the probe oscillate and fluctuate, so that the quality of test data is influenced. The more serious influence is that the hot wire is easy to break due to stretching, shaking and even impact under high pneumatic load, and the failure rate of the test is very high, which is an important reason that many high-speed wind tunnels cannot carry out the flow field turbulence test.

Therefore, in order to improve the test accuracy and reliability of the high-speed flow field hot wire technology, a high-speed flow field hot wire probe different from a common hot wire probe needs to be designed.

Disclosure of Invention

The invention aims to solve the technical problem of providing a one-dimensional hot wire probe suitable for high-speed flow field measurement, wherein the windward side of a hot wire is designed into an inwards concave arc shape, and the needle point of the probe and the hot wire are shaped by electroplating, so that the service life of the probe under high aerodynamic load and flow field particle impact can be obviously prolonged, the vibration of the hot wire in a flow field can be reduced, interference signals are reduced, and the test precision is improved.

The invention adopts the technical scheme for solving the technical problems that: a one-dimensional hot wire probe suitable for high-speed flow field measurements, the hot wire probe comprising: the device comprises a base, two hot wire probes and an arc-shaped hot wire;

the two hot wire probes are kept parallel, the bottoms of the two hot wire probes are arranged on the base, the top ends of the two probes are connected by adopting an arc-shaped hot wire, the radian of the arc-shaped hot wire faces to the air flow, the height h of an arc line is 0.2L, L is the distance between the tops of the two hot wire probes, L is more than or equal to 200d, and d represents the diameter of the hot wire;

the arc-shaped hot wire is made of tungsten wires;

and the front sections of the two hot wire probes, the arc-shaped hot wire, and the welding points of the hot wire probes and the arc-shaped hot wire are subjected to platinum electroplating or gold electroplating.

The invention has the beneficial effects that:

the one-dimensional hot wire probe comprises a probe, an inward concave arc-shaped hot wire facing the airflow and an integral coating at the front end of the probe, the chord height of the arc-shaped hot wire is determined according to test and calculation results, the integral coating is adopted for fixing and preventing the front end from being oxidized at high temperature, the service life of the probe under high aerodynamic load and flow field particle impact is obviously prolonged, meanwhile, the vibration of the hot wire in the flow field is reduced, pseudo signals are reduced, and the test precision is improved.

The invention aims to meet the hot-wire test of the high-speed wind tunnel and provides design reference for expanding the application of the hot-wire test technology in the high-speed flow field.

Drawings

FIG. 1 is a schematic view of a one-dimensional hot-wire probe for high-speed flow field

In the figure: 1. the hot wire probe I, the hot wire probe II, the arc-shaped hot wire, the hot wire probe base and the hot wire probe front end are sequentially arranged in sequence from top to bottom.

FIG. 2 is a schematic diagram of the front end of the probe

In the figure: l. arc hot wire chord length and h. arc hot wire chord height.

Detailed Description

Fig. 1 and 2 are schematic diagrams of a scheme of a high-speed flow field one-dimensional hot wire probe, fig. 1 is a structural schematic diagram of the high-speed flow field one-dimensional hot wire probe, and fig. 2 is a structural schematic diagram of a front end of the probe. In fig. 1, 1 is a first hot wire probe, 2 is a second hot wire probe, 3 is an arc-shaped hot wire, 4 is a hot wire probe base, and 5 is a hot wire probe tip. Fig. 2 shows the structure of the front end (5) of the hot wire probe and the arc-shaped hot wire (3), the hot wire material is pure tungsten wire, the design length of the chord length L is more than or equal to 200d for the hot wire with the diameter d, and the chord height is equal to 0.2L. After the arc-shaped hot wire (3) is welded, the whole front end (5) of the probe shown in figure 2 is plated with platinum, so that the functions of reinforcing the welding part, strengthening the hot wire, topologically shaping the hot wire and resisting oxidation of the tungsten wire are achieved. The one-dimensional hot wire probe with the high-speed flow field, which is manufactured by the invention, is used for testing the flow fields of a plurality of transonic wind tunnels, the speed of the tested flow field can reach more than Mach number 4, the service life of the probe is prolonged by more than 50%, and the testing precision is improved by more than 20%.

Claims

1. A one-dimensional hot wire probe suitable for high-speed flow field measurements, the hot wire probe comprising: the device comprises a base, two hot wire probes and an arc-shaped hot wire;

the two hot wire probes are kept parallel, the bottoms of the two hot wire probes are arranged on the base, the top ends of the two probes are connected by adopting an arc-shaped hot wire, the radian of the arc-shaped hot wire faces to the air flow, the chord h of the arc is 0.2L, L is the distance between the tops of the two hot wire probes, L is more than or equal to 200d, and d represents the diameter of the hot wire;

the arc-shaped hot wire is made of tungsten wires;

and the front ends of the two hot wire probes, the arc-shaped hot wire, and the welding point of the hot wire probes and the arc-shaped hot wire are subjected to platinum electroplating or gold electroplating.