The world's first set of engineering fluid wall shear stress tester was successfully developed

[ China Instrument Network Instrument R&D ] Recently, the research team of the Key Laboratory of Airspace Micro-nano System of the Northwestern Polytechnical University developed the world's first set of fluid wall surface shear stress tester.

In 2013, the “Development and Application of Fluid Wall Shear Stress Tester” developed by the Northwest University of Technology and led by the Ministry of Industry and Information Technology of the People’s Republic of China was officially established. The project aims at the research and development of experimental fluid dynamics instruments with the background of national major projects such as aerospace vehicles and new ships, and plans to develop a fluid wall shear stress tester with independent intellectual property rights, sound functions, and stable and reliable quality. In 2020, it will achieve an annual output of 150 units of production capacity, with a research funding of 65.58 million yuan.

The fluid wall surface shear stress is one of the most basic fluid mechanics parameters. It is a direct physical quantity to study the boundary layer flow state and is the most important basis for fine control and control of frictional resistance. However, due to the small value of shear stress, high dynamics, and the easily obstructed flow field in the measured flow field, there has been no effective test method and no special engineering instrument at home and abroad, which has affected the development of related science and technology industries and major engineering construction.

Northwestern Polytechnical University held several meetings in several years, promoting the development and application of the fluid wall surface shear stress tester, and finally successfully developed the world's first set of fluid wall surface shear stress tester. The tester makes full use of the unique advantages of high integration, high sensitivity, and good dynamics of micro-electro-mechanical systems (MEMS) technology. Through the establishment of micro-machining processes and test specifications, it has developed a flexible thermal-sensitive thin-film micro-sensor and a floating shear-stress micro-sensor. Critical core devices. The instrument is equipped with multi-channel probes that can capture flow field data at different locations and perform flow state analysis. The complete set of fluid wall shear stress test instruments has a measuring range of 0-60 Pa, a resolution of 0.3 Pa, an accuracy of 5%, and has the advantage of small disturbance to the flow field. .

In addition, Northwestern Polytechnical University has cooperated with China COMAC Shanghai Aircraft Design & Research Institute and other institutions to confirm that the instrument is equipped with high performance miniature sensitive probe technology, weak signal anti-interference measurement system technology and complex and harsh working environment probes. The package protection technology provides effective test data support for the design of large passenger aircraft, aero-engines, underwater vehicles and estuary coast engineering. And the instrument has reached the national standard GB/T6587-2012 (general specification of electronic measuring instruments) requirements.

At present, the team has completed the micro-sensor probe, instrument machine engineering manufacturing and testing platform, built the precision machining, assembly and other processes required for instrument production and reliability quality assurance system.

(Source: Northwestern Polytechnical University, Science and Technology Daily, Ministry of Industry and Information Technology)