自然风对发机喷流距离的影响

为评估起飞点后侧穿越方案的可行性，对自然风影响下的起飞飞机发动机喷流距离进行研究。喷流除了受发动机自身构型影响之外，自然风影响也不可忽略。本文采用CFD数值模拟方法，对自然风影响下的发动机喷流影响距离进行研究。首先，构建DES-SA数值模拟方法，进行标模验证；其次，选取3.5m/s作为自然风风速值，在静风及自然风条件下，结合典型机型发动机实际边界条件，分别对三种机型发动机喷流效应进行数值模拟，得出其在静风和自然风（3.5m/s）条件下的发动机喷流的影响距离。通过对比表明：相比于静风，3.5m/s的自然风在远场对喷流距离有较大影响。可见在研究发动机喷流时不可忽略自然风因素。

Research of distance influenced by a jet engine based on DES-SA method

In order to evaluate the feasibility of the backside crossing scheme, the jet distance of take-off aircraft under the influence of natural wind was studied. In addition to the influence of engine configuration, the influence of natural wind can not be ignored. In this paper, CFD numerical simulation method is used to study the influence distance of engine jet under the influence of natural wind. First, the numerical simulation method of DES-SA was constructed to verify the standard model. Secondly, 3.5m/s was selected as the wind speed value of natural wind. Combined with the actual boundary conditions of typical engines, the jet effects of three types of engines were numerically simulated under the conditions of static wind and natural wind, and the influence distance of engine jet under the conditions of static wind and natural wind (3.5m/s) was obtained. The comparison shows that compared with the quiet wind, the natural wind of 3.5m/s has a greater influence on the distance of the jet flow in the far field. It can be seen that the natural wind factor can not be ignored in the study of engine jet.