Numerical Simulation of Vortex Engine Flow Field： One Phase and Two Phases

• Published in: Journal of thermal science 2009-09, Vol.18 (3), p.226-234
• Main Authors: Najafi, A. F., Saemi, S. D., Saidi, M. H.
• Format: Article
• Language: English
• Subjects: Classical and Continuum Physics; Engineering Fluid Dynamics; Engineering Thermodynamics; Heat and Mass Transfer; Physics; Physics and Astronomy; 初始速度; 发动机; 拉格朗日方法; 数值模拟; 燃烧系统; 进口流场
• ISSN: 1003-2169; 1993-033X
• DOI: 10.1007/s11630-009-0226-y

Aiming at improving efficiency in combustion systems, the study on droplet behavior and its trajectory is of crucial importance. Vortex engine is a kind of internal combustion engine which uses swirl flow to achieve higher combustion efficiency. One of the important advantages of designing vortex engine is to reduce the temperature of walls by confining the combustion products in the inner vortex. The scopes of this investigation are to study vortex engine flow field as well as effective parameters on fuel droplet behavior such as droplet diameter, droplet initial velocity and inlet velocity of the flow field. The flow field is simulated using Reynolds Stress Transport Model （RSM）. The Eulerian-Lagrangian method and the one-way coupling approach are employed to simulate two phase flow and dispersed phase in the chamber, respectively. A new method, based on computing pressure force exerted on the droplet surface, is introduced to determine the distinction between using one-way and two-way coupling approaches. The results showed that the droplets with smaller diameter are more likely to follow the flow stream lines than bigger droplets, thus evaporate completely in the chamber. Moreover, droplets with greater initial velocity have higher evaporation rate, yielding the existence of evaporation and combustion in the inner vortex. Additionally, the higher inlet velocity of continuous phase results in higher centrifugal force, leads droplets in question to deviate towards the wall faster.