基于CFD动网格技术的飞艇动导数计算方法

A Method of Calculating Airship Dynamic Derivative Based on CFD Dynamic Mesh Technique

由于飞艇和飞机这两种飞行器在飞行原理、气动外形等方面都存在较大的差别,因此现有的飞机动导数工程估算公式和经验数据并不适用于飞艇动导数求解。为了解决上述问题,提出了一种新的基于CFD动网格技术的飞艇动导数计算方法。通过非结构化动网格技术,建立飞艇在流场中的强迫振动模型,采用有限体积法对N-S方程求解,研究飞艇在强迫振动中的气动特性变化规律,并基于数值计算结果求解飞艇的动导数。研究发现,得到的计算结果与风洞试验结果基本一致,表明基于CFD动网格技术进行飞艇的动导数求解是有效可行的。

There are many differences between airship and aircraft vehicle in flight theory, aerodynamic configuration etc, which leads to a result that the aircraft dynamic derivative calculating equations and da- ta are not applicable to the airship. To solve this problem, a new dynamic derivative calculating method applied to airship on the basis of CFD dynamic mesh technique is presented. First, forced vibration model of the airship in the atmosphere is set up based on unstructured dynamic mesh method. Then, the finite volume method is adopted to solve N- S equations. Finally, the airship dynamic derivatives are figured out on the basis of numeric computing results. The study indicates that the results obtained from the new method has a good accordance with the wind tunnel test, which confirms that the airship dynamic deriva- tive calculating method on the basis of CFD dynamic mesh technique is effective and feasible.