He chases his dream of deep blue sea with the wind blowing on the sea

"A seagull flies thousands of miles on the wind." Since ancient times, wind has meant freedom and power. It can send seagulls into the sky and drive sailboats. Now, in the eyes of Mu Anle, a wind energy expert and doctoral supervisor at Xi'an University of Technology, wind is not only a natural phenomenon, but also a clean source of green energy with infinite possibilities.

Wind has always been the most difficult force to control among all natural forces. It can be gentle and gentle, or it can be violent and devastating. Facing the variability of wind, ancient people were in awe and taboo, but Mu Anle chose to break through this barrier, face the strong wind, and experience the nature of wind firsthand. For decades, he has regarded wind as his friend, conducted research on the structural design, dynamic analysis and control of wind turbines, and devoted his life to the pursuit of converting wind power into clean kinetic energy for the benefit of mankind.

▲Mu Anle in the office

"My interests change with the country's strategic needs. Scientific and technological innovation should be oriented towards national economy and people's livelihood and solve practical problems." This is the scientific belief that Mu Anle has always upheld. It is this belief that gives "wind" energy and hope.

Starting point: a passion

In 1984, Mu Anle was admitted to the School of Mechanical and Electrical Engineering of Xidian University. At that time, he spent almost all his time in the library and laboratory. "I was particularly interested in mechanical vibration at that time, and my undergraduate tutors Liu Qingyun and Qiu Yuanying asked me to participate in a random vibration test project of the airborne plotter structure. I was responsible for the measurement of random vibration signals and the preprocessing and modeling analysis of dynamic data." This practice allowed him to enter the research field of vibration dynamics, and he deeply liked the research on mechanical dynamics and vibration control. After graduating from university, Mu Anle entered the Fourth Research Institute of the former Ministry of Aerospace to engage in the structural dynamic design of electronic equipment. After having a more three-dimensional and comprehensive understanding of aerospace engineering technology, he realized that it was far from enough to rely solely on simple knowledge during college. In order to achieve higher achievements in the field of aerospace, it is necessary to systematically learn cutting-edge professional knowledge such as mechanical dynamics, modern control theory, and system optimization theory. So he applied for a master's degree at the School of Mechanical Engineering of Xi'an Jiaotong University, and studied under Professor Cao Longhua, a well-known domestic expert in mechanical dynamics. In 1993, after obtaining a master's degree, Mu Anle chose to stay at the school to teach and began a long academic research career.

In 2003, Mu Anle received a scholarship from the Japanese government during his doctoral studies and went to Kitakyushu Institute of Technology in Japan for exchange and study. During his stay in Japan, in addition to conducting academic research in university laboratories, he also visited many well-known Japanese companies, such as Nissan, Nippon Steel, Yaskawa Electric, Mitsubishi Chemical and Mitsubishi Heavy Industries, and had in-depth exchanges with them. This experience made Mu Anle deeply feel the gap between China's scientific and technological level and Japan's at that time. Especially when visiting Mitsubishi Heavy Industries, when he saw that their company headquarters in Nagasaki could remotely control the coastal wind farm hundreds of kilometers away, Mu Anle had a deeper feeling of the magic of wind power technology, and also realized the gap in my country in this regard, so he made up his mind to carry out research on wind turbine dynamics and control. At that time, due to the dual pressure of environmental pollution and energy shortage, China was very eager for wind energy technology, but it was limited by the domestic technical level and the wind power generation technology was very backward. To overcome such wind power technology problems, hard work must be done. Mu Anle knew that there was no shortcut to scientific research, and he could only be down-to-earth. After a lot of research and in-depth study, he finally proposed a new control method for variable speed constant frequency and maximum power point tracking of electromechanical hybrid drive, published a number of internationally influential papers, and applied for a number of invention patents. These achievements have attracted the interest and attention of well-known domestic wind power companies, and they will go to the laboratory to further communicate and discuss cooperation with Mu Anle's team.

In 2010, Mu Anle was favored and funded by Professor Mark J. Balas, the head of the Department of Electronic and Computer Engineering at the University of Wyoming and a pioneer in the field of wind power control in the United States, and began postdoctoral research on wind turbine flow control at the university. After returning to China, he became a professor and doctoral supervisor at Xi'an University of Technology, and continued to lead students in conducting research on dynamics and control related to wind power.

Breakthrough: Obsession with the Wind

For decades, Mu Anle has been focusing on the field of renewable energy, and his research work has mainly focused on the structural design, dynamic analysis and control research of offshore floating wind power generation systems. Contrary to what the outside world thinks, this research itself is extremely difficult and has a wide range.

The offshore floating wind turbine is a complex interdisciplinary system that requires the comprehensive use of knowledge in multiple fields such as mechanics, aerospace, automatic control, electrical, and materials. Only when professional knowledge in different fields complement each other can a more systematic and optimized design scheme be formed. The integration of multidisciplinary professional knowledge has not only promoted the technical and theoretical innovation of Mu Anle's team, but also helped them improve their comprehensive capabilities and broaden their horizons. For example, when conducting research on low-wind-speed start-up control of wind turbines, Mu Anle and his team tried various aerodynamic designs of wind turbine blades, but it was still difficult to substantially improve the wind energy conversion efficiency of traditional blades. The embarrassing situation forced them to find another way and creatively proposed a hybrid drive solution based on the "Magnus effect", which significantly improved the start-up performance at low wind speeds. After optimization and iteration, this achievement became a landmark achievement of the team's research, and received support from multiple funds including the National Natural Science Foundation, published a number of internationally influential papers, and applied for a number of invention patents.

When studying high wind speed control of wind turbines, modeling became a difficult problem for Mu Anle. Initially, the team was unable to accurately describe the aeroelastic characteristics of the wing due to the use of an overly simplified mathematical model. To overcome the difficulties, they invited experts from the School of Aeronautics for guidance and switched to a more rigorous gas-solid coupling model that considers a dynamic stall model. The new model takes into account the bending and torsional deformation of the wind turbine blades, greatly improving the calculation accuracy. The team eventually designed an effective active flow control strategy to ensure the dynamic stability of the wind turbine in strong wind environments.

The cross-integration of multiple disciplines has brought new collisions and achievements. In recent years, Mu Anle's team has started a research project on offshore wind power. Compared with onshore wind farms, the advantages of offshore wind farms are mainly that they do not occupy land resources, are basically not affected by topography, have higher wind speeds, and have richer wind energy resources, but offshore wind power faces more unknown technical problems. In the early stages of the project, the team considered the stability of the structural dynamics of the wind turbine system in the design, but ignored the influence of different sea waves on the relative motion between floating bodies on the anchor chain. At that time, students with a mechanics background in the team believed that the design did not take into account the coupling effect between the floating body movements, while students majoring in control insisted that the real-time control system needed to add an adaptive adjustment mechanism. Faced with differences, after intense discussions, Mu Anle, as a mentor, determined to use a deep draft column platform (SPAR) structure with robust adaptive control of an active extended tuned mass damper (ETAMD), and developed a three-floating tandem offshore wind power platform with stable structure and robust control. This design fully considers the kinematic characteristics of the floating body and realizes the adaptive control of the platform. This achievement provides a new design solution for my country's offshore wind power generation.

In terms of technology promotion and industrialization, Mu Anle proposed the idea of ​​realizing intelligent oil pumping in oil wells through hybrid drive of wind power and motors. In terms of key technologies, he also developed an intelligent hybrid drive control system to coordinate the output of wind turbines and motors, ensure the stable movement of the pumping rod, and optimize the pumping efficiency. At present, this technology has been industrialized in Changqing Oilfield in Shaanxi Province, and compared with traditional pumping methods, it has increased the pumping efficiency by about 15%.

The future: a new promise

"Developing independent wind power equipment and achieving technological independence is the historical responsibility of our generation of scientific researchers." Keeping in mind the mission, Mu Anle has presided over and participated in 16 scientific research projects including the National Major Special Fund and the National Natural Science Foundation over the years, conducted systematic and original research in the field of wind turbines, and achieved a series of innovative results in wind power technology. In terms of blade optimization design, he used a sophisticated three-dimensional numerical calculation method for the first time, taking into account the complex aerodynamic effects of the blades, to achieve lightweight design of the blades and efficient use of wind energy; in terms of wind turbine control, Mu Anle and his team also developed an active blade control system based on adaptive fluid mechanics. This system can adjust the shape of the blades in real time according to changes in the ambient wind speed, maximize the capture of wind energy, and significantly increase power generation. This technology also fills the gap in related aspects in China. In addition to achieving fruitful results in wind turbine research, Mu Anle has made outstanding explorations and contributions in promoting the development of mechanical engineering, large-scale energy storage technology research, and the application of Internet of Things technology in people's livelihood and medical fields.

As a teacher, Mu Anle always shoulders the social responsibility of spreading knowledge and enlightening thoughts, and strives to cultivate outstanding talents; as a scientific researcher, he adheres to the purpose of scientific and technological innovation to focus on national economy and people's livelihood and solve practical problems to complete each project.

Mu Anle also has clear plans for the future. He and his team are conducting research projects such as aerodynamic modeling of wind turbines, dynamics and control of offshore floating wind turbines, large-scale liquid flow battery energy storage for wind power, and control optimization of medical robots. "In the next 3 to 5 years, I plan to continue to conduct cutting-edge technology research in the fields of wind power equipment, large-scale energy storage, and medical robots, and publish high-level papers; strive to undertake more national scientific research projects to ensure that our research is at the international leading level in related fields. At the same time, our team will continue to promote the transformation and application of scientific research results, strengthen industry-university-research cooperation, and promote the transformation of technological achievements to the industry; we will also actively apply for and build provincial and ministerial key disciplines, and strive to build the team into a high-level scientific research team in related fields, and cultivate more outstanding engineering and technical talents for the country." The sky does not speak, but the four seasons go on; the earth does not speak, but all things grow. Time is the best proof. This is Mu Anle's expectation for the future, and it is also a sincere promise.