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doi:10.1016/j.energy.2004.08.028

04 Published by Elsevier Ltd

Energy 30 (2005) 1–3

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Editorial

A 70th birthday tribute to Academician Ruixian Cai

Academician Cai, an Associate Editor of Energy, studied in Tsinghua University, the Beijing

Institute of Aeronautics (now, BUAA), and Jiaotong University, and graduated from Jiaotong

University in 1956. His early career included a faculty position in the Power Engineering

Department of Tsinghua University, six years’ engineering experience in Changchun Locomotive

Works, and a faculty position at the Institute of Mechanics, Chinese Academy of Sciences.

From 1980, he was Research Associate Professor, Research Professor, Vice Director and then

Director of the Institute of Engineering Thermophysics, Chinese Academy of Sciences.Academician Cai is a top Chinese scientist in the field of power engineering. With experience

and great success in academia, industry, and research institutes, he was appointed in 1991 as

Academician, Chinese Academy of Sciences, and from 1994 till 2002, he served as Director,

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 Inter-

national Society for Air Breathing Engines, member of the Turbomachinery Committee of

the International Gas Turbine Institute, the president of the Chinese Society of Engineering

Editorial / Energy 30 (2005) 1–32

Thermophysics, member of the Scientific Committee of the ECOS series of international confer-ences, and standing member of some other professional societies in China.He has guided many students and won the excellent teacher award many times, and four of

his former students have become Academicians of China.Just after his graduation in the 1950s, he was honored to be chosen as the first assistant of

Academician Wu, a founder of 3D turbomachinery flow theory in the world, in Tsinghua Uni-versity. He made significant advancements in Wu’s theory, primarily in the following areas.(1) He developed the mean streamline method, which was, in the 1950s and 1960s, the onlymethod for the effective calculation of compressible cascade flow without a computer; heimproved the calculation speed and precision of this method by an order of magnitude, andexpanded its usable range from subsonic to low transonic flow and from turbine cascade toother flow channels. These achievements have been quoted by international textbooks and otherpublications. (2) He found a constraint condition on the turbomachinery circular wall whichhad not been included in Wu’s original 3D turbomachinery flow theory.When he worked in industry in the 1970s, as the only gas turbine expert in the factory, he

took part in successfully designing and manufacturing a 4500 hp gas turbine locomotive proto-type without any foreign help. He discovered an effect of the inner shroud of axial compressorson its performance, especially its surge limit. Some other axial compressors made in China wereimproved later with the understanding of this effect, which is still being studied around theworld.Academician Cai has been engaged in the basic study of counter-rotating turbines since the

late 1980s. He developed a basic analysis of such turbines that is the most comprehensive one inthe open literature, and has been referred to by Chinese military jet engine researchers.From the 1980s, he has taken part in the study of complex thermal cycles. There have been

three main achievements in this field. (1) Proposing a ‘‘comparison method’’ to easily analyze andpresent the performance of various complex cycles. With this method, he was the first (publishedin 1981, in Chinese) to prove that the optimal pressure ratio for efficiency of combined cycles isapproximately equal to the optimal pressure ratio for the specific output of simple cycle gas tur-bines. (2) Pointing out the irrationality of many widely used evaluation criteria in cycle analyses,and developing correct criteria and new analysis results. For example, he has shown that the effec-tiveness of recuperators has to be replaced by the average heat transfer temperature difference.(3) Proposing some new cycles, for example, a novel hydrogen and oxygen combined cycle whicheliminates the heat transfer process from the topping to the bottoming cycle in the conventionalcombined cycle.Recently, he has been deriving many new algebraically explicit analytical solutions for the

governing equations of flow and heat transfer etc. Most of the governing equations are non-linear, and analytical solutions for them have not been found before, for example, the governingequations of unsteady compressible flow and nonlinear heat transfer. Besides having theoreticalsignificance, analytical solutions can also serve as benchmarks for computational fluid dynamicsand computational heat transfer; many papers on such analytical solutions have been publishedin major international journals.He is still active in scientific research, and advises many graduate students.We all convey to Academician Cai our congratulations on his birthday, and our most cordial

wishes for his good health and continuing productive work and life.

Olav BollandChristos A. FrangopoulosRichard A. GaggioliZengyuan GuoBen HuaMasaru IshidaHongde JiangHongguang Jin (Editor)Rumou LinZonghu Lin

Noam LiorMichael J. MoranRicardo RiveroGeorge TsatsaronisAntonio ValeroMichael R. von SpakovskyJianzhong XuJinyue YanShizheng ZhangYuan Zhou

3Editorial / Energy 30 (2005) 1–3

Hongguang JinE-mail address: HGJIN@mail.etp.ac.cn

doi:10.1016/j.energy.2004.08.028