On thermal convection between two coaxial square containers inclined by 45°

Abstract This paper is concerned with flow visualization, velocity, streakline, and heat transfer measurements on thermal convection between two coaxial square containers inclined by 45°. It is found that there is no critical Rayleigh number (Ra)c for the onset of thermal convection in the test section. There appear two great circulations, which are symmetrical with respect to the diagonal vertical plane of the two coaxial square containers, and enhance the heat transfer significantly.