无上部抽吸装置储罐区人工龙卷风风场模拟

为了减少因储罐泄漏位置不确定造成的人员伤亡,指导应急疏散,提出利用人工龙卷风定向控制气体流动方向的模型。首先基于Fluent软件建立了储罐区域人工龙卷风数值模型,分析切向速度和压强沿径向变化规律,发现与经典Rankine涡模型切向速度沿径向分布规律一致,证实可在储罐区以射流相切的方式形成人工龙卷风风场。其次研究了涡流比和进风量对风场控制气流特性的影响,即分析形成的龙卷风风场最大切向速度、压强差变化规律,结果表明,涡流比越大,形成的龙卷风风场中切向速度和压强差越小,即气流向中心汇聚能力越弱;进风量越大,形成的龙卷风风场中切向速度和压强差越大,即气流向中心汇聚能力越强。研究表明,用人工龙卷风控制储罐泄漏气流方向是可行的。

Numerical simulation for the artificial tornado field in a storage tank area with no suction device

In this paper,the author intends to propose a renovated artificial tornado control model to reduce the likely casualties to be caused by the uncertain leakage location of the storage tank and unexpected evacuation airflow direction. For the study purpose,we have established a numerical simulation model for the artificial tornado in the tank area with no up-down oriented suction device by using a software known as the Fluent. And,so,the suction effect of the tornado field can thus be formed through a tangent jet so as to drive and control the gas flow around the tank. To achieve the purpose,it is necessary to analyze the variation of the tangent velocity and the pressure in the radial direction,which should be made in line with the ideal Rankine vortex model and that of the theoretical tornado field formula. What is more,the artificial tornado field has to be formed in the storage tank area and set up to result in the artificial tornado to control the air flow at the maximum tangent velocity and pressure difference at the different heights. And,in so doing,it would be possible to control the air flow by measuring the maximum tangent velocity and the pressure difference at different heights. In addition,the tornado field can be made clear by changing the swirl ratio and the air intake. Thus,corresponding conclusions can be made with the help of the 2 different calculation models. In the first model,the air intake can be gained by changing the swirl ratio. The results of the above study indicate that,with the increase of the swirl ratio,the maximum tangent velocity and the pressure difference at the same height tend to be decreased. That is to say,the greater the swirl ratio,the weaker the power and pressure of the tornado field tend to converge the air flow. On the other hand,with the second model,the swirl ratio constant can be controlled with the change of the air intake. Thus,the result shows that,with the increase of the air intake,the maximum tangent velocity and pressure difference at the same height may tend to be increasing correspondingly. And,more exactly speaking,the greater the air intake,the stronger the capability of the tornado field to converge the air flow. Therefore,the given method can be said in a position to provide a novel research idea for numerical simulation and analysis of the artificial tornado field characteristics as well as a new research approach to the directional control of the air flow.