The fluid motion characteristics have an important influence on the evolution of the backflow vortex near the pipe wall. The instantaneous velocity and instantaneous temperature of the outlet flow channel section, the shear stress of the outlet flow channel wall, the boundary layer thickness, and the Nusselt number under different ratios of the upstream and downstream pipe diameter are studied at the inlet pressure of 12,000 Pa, using the large eddy simulation numerical method. The research results show that a pulsating flow is presented in the outlet channel of the self-excited oscillation chamber, and a backflow vortex can be formed near the wall of the outlet channel. The heat exchange between the fluid near the wall and the wall is accelerated due to the backflow vortex. The thickness of the boundary layer near the wall first decreases and then increases when the ratio of the upstream and downstream pipe diameters of the self-excited oscillation chamber is 1 to 1.8, whereas the heat transfer efficiency first increases and then decreases. The minimum boundary layer thickness is 0.385 mm. The maximum comprehensive evaluation factor is 1.23 when the is 1.5. The total heat exchange efficiency increases by 23%.
Study on Heat Transfer in Self-Excited Oscillation with Backflow Vortex Disturbance Effect
Journal of Thermophysics and Heat Transfer ; 35 , 3 ; 569-579
2021-02-08
11 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Thermodynamic Effect on Backflow Vortex Cavitation
AIAA | 2015
|Thermodynamic Effect on Backflow Vortex Cavitation (AIAA 2015-0471)
British Library Conference Proceedings | 2015
|Experimental Visualization of Cryogenic Backflow Vortex Cavitation with Thermodynamic Effects
Online Contents | 2016
|