WO2020237828A1

WO2020237828A1 - High-precision total temperature probe device with low own loss

Info

Publication number: WO2020237828A1
Application number: PCT/CN2019/099412
Authority: WO
Inventors: 崔佳欢; 刘俭; 王稳
Original assignee: 浙江大学
Priority date: 2019-05-28
Filing date: 2019-08-06
Publication date: 2020-12-03
Also published as: CN110160667A

Abstract

A high-precision total temperature probe device with low own loss. The device is mounted on a blade leading edge of a rotating mechanical blade of an aerospace vehicle, and comprises a probe body, wherein the probe body is provided with two layers of chambers, which are respectively marked as a stagnant layer (2) and a thermal insulating layer (3); the thermal insulating layer (3) is provided outside the stagnant layer (2) in a sheathed manner; the stagnant layer contains a temperature sensor (1); a first through hole (4) is provided between the stagnant layer (2) and the thermal insulating layer (3); and the bottom of the thermal insulating layer (3) is provided with second through holes (5) in the direction of a vane pitch. The device for measuring a total temperature is aimed at precisely measuring a stagnation temperature of a blade leading edge and reducing the loss caused by the temperature measuring device, so as to achieve more precise total temperature measurement insofar as the impact of an original flow field is as small as possible.

Description

A total temperature probe device with low self-loss and high precision

Technical field

The invention relates to a rotating mechanical blade suitable for aerospace aircraft. The structure has high accuracy, and the loss generated by the measuring device is small, and the effect on the efficiency of the whole machine is small.

Background technique

With the increase in energy demand, petroleum as a non-renewable energy source is facing a shortage of resources. Aircraft manufacturers, engine manufacturers and related organizations are all actively working to improve fuel efficiency. The measurement accuracy of thermal efficiency will directly affect the calculation of aircraft efficiency, and thermal efficiency is related to the measured total temperature. Therefore, in order to accurately measure the performance and efficiency of spacecraft, we must measure the total temperature and total pressure in the engine. At present, the general measurement method is to install a temperature probe at the axial or circumferential position of the engine, often at the leading edge of the blade.

When the total temperature probe measures the total temperature, the fluid flowing through the temperature sensor needs to be slowed down. Ideally, the total temperature measurement equipment is insulated from the outside, and the fluid near the temperature sensor stagnates. In fact, the measurement device cannot meet the adiabatic state, which is caused by temperature heat exchange. Measurement error, so the actual measured temperature T _{m is} less than the stagnation temperature T _t , and the difference between them is defined as the temperature recovery coefficient

In the formula, T _s represents the resting temperature, and the value of R _f ranges from 0-1. When R _f =1, the temperature is the stagnation temperature. Installing a temperature probe in the flow field will bring additional losses, so it must be considered to minimize the influence of the device on the loss to ensure that the thermal efficiency calculated by the temperature probe is not much different from the real thermal efficiency.

Summary of the invention

The purpose of the present invention is to provide an accurate total temperature measuring device in view of the deficiencies of the prior art. Compared with the existing total temperature measuring device, the invention has the advantages of high measurement accuracy and low flow loss.

In order to achieve the above purpose, the following technical solutions are implemented: a total temperature probe device with low self-loss and high precision, the total temperature probe device is installed on the leading edge of the blade of the rotating mechanical blade of an aerospace vehicle, and the total temperature The probe device includes the probe body. There are two layers of chambers on the probe body, which are marked as stagnation layer and heat insulation layer. The heat insulation layer is sheathed outside the stagnation layer. The stagnation layer contains a temperature sensor, a stagnation layer and A first through hole is opened between the heat insulation layers, and a second through hole is opened along the cascade pitch direction at the bottom of the heat insulation layer.

Further, the first through hole is located on a side close to the blade position.

Further, there are multiple first through holes, and the multiple first through holes are uniformly distributed along the circumferential direction of the probe body.

Further, there are multiple second through holes, and the multiple second through holes are evenly distributed along the circumferential direction of the probe body.

Further, the probe body is cylindrical, with a cylindrical cavity opened in the hollow to form a stagnation layer; a flat side of the cylindrical cavity is open; a cylindrical annular cavity is also opened outside the cylindrical cavity to form a partition Thermal layer.

Further, a temperature sensor support extends inward in the stagnation layer of the probe body, a probe support extends outward from the bottom of the probe body, and lead holes penetrate through the temperature sensor support and the probe support.

Further, the temperature sensor is a thermocouple or a thermal resistance.

Compared with the prior art, the beneficial effect of the present invention is that by providing dual chambers, the stagnation layer mainly functions to measure temperature, and the function of the heat insulation layer is to reduce the measurement error caused by the heat exchange between the mainstream fluid and the stagnation layer fluid. , The total temperature is accurately measured, and the opening at the bottom of the insulation layer allows the fluid to flow out along the main flow direction, destroying the separation bubble at the connection position of the insulation layer and the support, and reducing the flow loss.

Description of the drawings

Figure 1 is a three-dimensional schematic diagram of the present invention;

Figure 2 is a front view of the present invention;

Figure 3-4 is a cross-sectional view of the present invention;

Figure 5 is a perspective view of the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the low-pressure turbine blade of the present invention will be described in detail below with reference to the drawings and specific embodiments.

As shown in Figures 1-5, the present invention provides a total temperature probe device with low self-loss and high accuracy. The total temperature probe device is installed on the leading edge of the blade of a rotating mechanical blade of an aerospace vehicle. Including the probe body, there are two layers of chambers on the probe body, which are respectively marked as stagnation layer 2 and heat insulation layer 3. The heat insulation layer 3 is set outside the stagnation layer 2, and the stagnation layer 2 contains the temperature sensor 1. A first through hole 4 is opened between the stagnation layer 2 and the heat insulation layer 3, and a second through hole 5 is opened at the bottom of the heat insulation layer 3 along the cascade pitch direction. The purpose of the thermal insulation layer 3 is to isolate the heat exchange between the mainstream fluid and the fluid in the stagnation layer 2. The fluid in the thermal insulation layer 3 flows out in the main flow direction through the second through hole 5, blowing away the separation bubbles at the tail of the probe, and reducing the flow loss caused by the installation of the probe.

A further technical solution is that the first through hole 4 is located on the side close to the position of the blade; the first through hole 4 has multiple, and the multiple first through holes 4 are evenly distributed along the circumferential direction of the probe body. There are multiple second through holes 5, and the multiple second through holes 5 are evenly distributed along the circumferential direction of the probe body. Two examples are given in the drawings.

A further technical solution is that the probe body is cylindrical, a cylindrical cavity is opened in the hollow to form a stagnation layer 2; a plane side of the cylindrical cavity is open; and a cylindrical annular cavity is also opened outside the cylindrical cavity The body, the thermal insulation layer 3 is formed.

A further technical solution is that the stagnation layer 2 of the probe body extends inwardly with a temperature sensor support, the bottom of the probe body extends outwards with a probe support 7, and the temperature sensor support and the probe support 7 penetrate Lead hole.

A further technical solution is that the temperature sensor may be a thermocouple or a thermal resistance.

When in use, the total temperature probe device of the present invention is installed on the leading edge of the blade, the axis is perpendicular to the leading edge of the blade, and a plurality of total temperature probes are installed along the height direction of the blade to reduce measurement errors caused by uneven distribution of total temperature. The temperature sensor 1 is connected to the temperature sensor 1 through a wire inserted into the lead hole. The temperature sensor 1 contacts the main flow fluid to convert the heat signal into a heat signal, and the temperature value is measured by the connected computer. The fluid in the stagnant layer 2 flows into the thermal insulation layer 3 through the first through hole 4.

The working principle of the total temperature measuring device provided by the present invention is now explained as follows: the early total temperature measuring device has only one chamber, the temperature sensor is installed in the chamber, and the chamber is closed. The disadvantage of this method is that the incoming fluid cannot affect the total temperature. The temperature probe continues to heat up, causing large measurement errors. Gradually developed into the chamber near the blades to increase the exhaust holes, using this method, the incoming gas can continue to heat the total temperature probe, but due to the temperature difference between the inner and outer walls of the chamber, there is heat exchange, which has an impact on the measured total temperature. The axial direction of the exhaust hole is perpendicular to the main flow direction, and the jet flow affects the following blade performance experiments. On the basis of the single-chamber temperature measuring device, the present invention is improved into two chambers. The main function of the outer chamber is to isolate the influence of the temperature of the mainstream fluid on the temperature of the inner chamber fluid, and the exhaust hole is provided at the bottom of the outer chamber. Effectively reduce the separation bubbles generated by the fluid at the connection position of the outer chamber and the support, and the fluid flowing out of the exhaust hole can destroy the separation bubbles. Compared with the existing total temperature measuring device, the measuring device provided by the present invention optimizes the loss caused by the measuring device, and has little influence on the efficiency calculation of the whole machine.

In addition, it should be noted that the “first” and “second” mentioned in this embodiment do not represent an absolute distinguishing relationship in terms of structure or function, but are merely for the convenience of description. After considering the specification and practicing the disclosure disclosed herein, those skilled in the art will easily think of other embodiments of the present application. This application is intended to cover any variations, uses, or adaptive changes of the present disclosure. These variations, uses, or adaptive changes follow the general principles of the present disclosure and include common knowledge or conventional technical means in the technical field not disclosed in this application . The description and embodiments are only regarded as exemplary, and the true scope and spirit of the application are pointed out by the following claims.

It should be understood that the present application is not limited to the precise structure that has been described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the application is only limited by the appended claims.

Claims

A total temperature probe device with low self-loss and high accuracy. The total temperature probe device is installed on the leading edge of the blade of a rotating mechanical blade of an aerospace vehicle. The feature is that the total temperature probe device includes a probe body, etc. There are two layers of chambers on the upper side, which are respectively marked as stagnant layer and heat insulating layer. The insulating layer is sleeved outside the stagnant layer. The stagnant layer contains a temperature sensor. There is a section between the stagnant layer and the insulating layer. A through hole, a second through hole is opened at the bottom of the heat insulation layer along the cascade pitch direction.
The total temperature probe device with low self-loss and high precision according to claim 1, wherein the first through hole is located on the side close to the blade position.
The total temperature probe device with low self-loss and high precision according to claim 2, characterized in that there are multiple first through holes, and the multiple first through holes are evenly distributed along the circumferential direction of the probe body.
The total temperature probe device with low self-loss and high precision according to claim 3, characterized in that there are multiple second through holes, and the multiple second through holes are evenly distributed along the circumferential direction of the probe body.
The total temperature probe device with low self-loss and high precision according to claim 4, characterized in that the probe body is cylindrical with a cylindrical cavity in the hollow to form a stagnation layer; One plane side of the body is open; a cylindrical annular cavity is also opened outside the cylindrical cavity to form a heat insulation layer.
The total temperature probe device with low self-loss and high precision according to claim 5, wherein a temperature sensor support extends inward in the stagnation layer of the probe body, and the bottom of the probe body extends outward There is a probe support, and a lead hole runs through the temperature sensor support and the probe support.
The temperature measuring device according to claim 6, wherein the temperature sensor is a thermocouple or a thermal resistance.