根据湍流管流中柴油机微粒热泳沉降和湍流脉动沉降研究的需要,对脉动排气时排气管内近壁流场的分布特征、影响因素以及变化规律等进行了研究;分析了脉动排气时气流速度的脉动振幅和脉动频率对管内近壁处温度场和湍动能场的影响.研究结果表明,与稳态排气流动相比,脉动排气时近壁流场的分布和变化特征有很大不同,从而会对微粒的热泳沉降和湍流脉动沉降产生很大的影响.
According to the needs of the research on the thermophoresis deposition and turbulent deposition of diesel particulates in the exhaust pipe,the distribution characteristics,influence factors and variation regularity of the near-wall flow field in the pulsation turbulent tube were studied,the influence of the pulsation amplitude and pulsation frequency on the near-wall temperature field and turbulent kinetic energy field in the turbulent tube were analyzed. The research results show that the characteristics of the distribution and variation of the near-wall flow field in the pulsation turbulent tube are different from that of the steady flow and would have a great influence on the thermophoresis deposition and turbulent deposition of diesel particulates in the exhaust tube.