超临界航空煤油RP-3沉积过程的数值研究

Numerical study of pressure effects on supercritical aviation kerosene RP-3 deposition processes

中文关键词: 超临界流体  动力学  两相流  计算流体力学

英文关键词: Supercritical fluid  Kinetics  Two-phase flow  computational fluid dypesition ,CFD

中文摘要:

      基于欧拉-拉格朗日方法，对冷却管道内超临界航空煤油焦炭颗粒沉积过程进行了数值模拟研究。物理模型为内径1.8mm、长度2000mm的细圆管，数值计算模型中考虑了流体对颗粒的曳力、重力、Saffman力和附加质量力等。假设物理模型入口处已产生航空煤油焦炭颗粒，重点研究了航空煤油压力对焦炭颗粒沉积过程的影响。研究结果表明，压力对颗粒沉积过程的影响与颗粒大小、温度有着密切的关系。对于10μm、50μm、70μm的焦炭颗粒，煤油处于低温区时，压力对颗粒沉积过程影响并不显著，较高的压力对焦炭颗粒沉积略有抑制作用；然而随着温度的升高，压力升高对颗粒沉积过程具有明显的抑制作用。对于30μm的焦炭颗粒而言，高压反而有利于颗粒沉积。此外，对不同流动方式下颗粒沉积率进行了研究，结果发现竖直向上管中颗粒沉积率最低。

英文摘要:

      Using Euler-Lagrange method, the deposition process of supercritical aviation kerosene (RP-3) in a cooling channel was numerically investigated. The physical model was a tube with 1.8 mm inner diameter and 2000mm length. In the simulation, the drag force, gravity, Saffman force and virtual mass force, etc. were considered. It was assumed that the carbon particles were already formed at the entrance of the tube. The study focuses on the effect of pressure on the deposition processes of particles with different diameters. It is indicated that the temperature and particle size have a strong relationship with this effect. For carbon particles with diameter of 10μm、50μm and 70μm, the effect of pressure is not obvious when kerosene is in the low-temperature zone, while high pressure has a slight inhibiting effect on the deposition process. Nevertheless, in the high-temperature zone, high pressure strongly inhibits the deposition process. The specific effect was in relationship with the particle size. For particles with diameter of 30μm, high pressure has a promoting effect on the deposition process. In addition, the vertical upward flow results in the lowest deposition rate among different flow directions.