Professor Liu has taught at Shanghai University Mechanics Research Institute. He has long been engaged in the research of pneumatic theory of turbomachine and hydromechanics.^[2] Based on Wu Zhonghua's 3D fluid theory of turbomachine, he established a new theory system with the variation theory as a foundation. Liu introduced a systematic channel of the establishment and transformation of the hydromechanical variation principle. He was the first scientist to set up variation principle and broad-sense variation principle families of positive proposition, reverse proposition and cross proposition of turbomachine's 3D flow.^[3]

Professor Liu discovered optimized design theory about the 3D cascade and runner, combined with optimized cybernetics. He developed a field change and variation theory and a finite element method in which various unknown interfaces can be automatically captured. He also put forward a series of new general functions for hydromechanics,^[4] and explored general theory and solution about mapping space of 3D flow reverse - cross proposition. In the last few decades, Liu has emphasized new directions, such as reverse proposition of nonsteady pneumatic mechanics, reverse proposition of multi-working condition points hydromechanics and pneumatic - thermal - elastic coupling theory.

Professor Liu won the second award of national natural science in 1987, and was elected an academician of the Chinese Academy of Sciences in 1999.