Cai, RuiXian Academician, born in 1934. Studied in Tsinghua University, Beijing Institute of Aeronautics (now BUAA), and graduated from Jiaotong University in 1956. He was assoc. prof., prof., deputy director and director of the Institute of Engineering Thermophysics(IET). He is a top Chinese scientist in the field of power engineering, and was appointed in 1991 as academician of CAS, and from 1994 till 2002 he was Director of Department of Engineering and Materials Sciences, National Natural Science Foundation of China. He is also a member of the executive committee and representative of China of the International Society for Air Breathing Engines, member of the Turbomachinery Committee of the International Gas Turbine Institute, the president of the Chinese Society of Engineering Thermophysics, member of the Scientific Committee of the ECOS series of international conferences, associate editor of ENERGY. He has guided many students, won the excellent teacher award many times, and four of his former students became academicians in China. He has made significant advancements in Wu’s 3D turbomachinery flow theory, primarily in (1) developing the Mean Streamline Method, improved the calculation speed and precision of this method by an order of magnitude, and expanded its usable range from subsonic to low transonic flow and from turbine cascade to other flow channels. These achievements have been quoted by international textbooks and other publications; (2) found a constraint condition on turbomachinery circular wall which has not been included in Wu’s original 3D turbomachinery flow theory. He discovered an effect of the inner shroud of axial compressors on its performance, especially its surge limit. Some other axial compressors made in China were improved later with the understanding of this effect, which is still being studied in the world. He was engaged in the basic study of counter-rotating turbines since the late eighties. He developed a basic analysis of such turbines that is the most comprehensive one in the open literature, and has been referred-to by the Chinese military jet engine researchers. Since the eighties he has taken part in the research of complex thermal cycles. There have been three main achievements in this field: (1) Proposing a “Comparison Method” to easily analyze and present the performance of various complex cycles. With this method he is the first (published in 1981, in Chinese) to prove that the optimal pressure ratio for efficiency of combined cycles is approximately equal to the optimal pressure ratio for the specific output of simple cycle gas turbines; (2) pointing out the irrationality of many widely used evaluation criteria in cycle analyses, and developing correct criteria and new analysis results. (3) proposing some new cycles, for example, a novel hydrogen and oxygen combined cycle which eliminates the heat transfer process from the topping to the bottoming cycle in the conventional combined cycle. Recently, he has been deriving many new algebraically explicit analytical solutions for the governing equations of flow and heat transfer. Most of the governing equations are nonlinear and analytical solutions for them had not been found before.. Besides their theoretical significance, analytical solutions can also serve as benchmarks for computational fluid dynamics and computational heat transfer, many papers about such analytical solutions have been published in major international journals. He has published more than 100 papers in domestic and international journals. He was awarded the second-class National Prize, and other prizes.