二次空气系统盘腔一维非定常计算方法

One-dimensional unsteady simulation method of cavity in secondary air system

通过对盘腔结构的一维算法展开研究,提出适用于具有非标准结构、包含多个进出口的复杂盘腔的一维建模规则,并采用特征线法,实现盘腔结构的一维非定常流动与换热的计算,通过将广义的变截面、有摩擦、考虑对外热交换的盘腔一维可压缩非定常流动与换热的偏微分方程组转换为常微分方程组,进而获得盘腔内部沿流动方向压力、流量、温度等系统参数的特征线数值解,采用商业计算流体软件CFX对其进行验证.结果表明:所提出的盘腔建模与计算规则能够直观且准确地描述盘腔一维非定常流动及换热特征,仿真结果与CFX计算结果最大偏差约为9.4%,可应用于具有非标准结构的多接口复杂盘腔的模拟,可以作为二次空气系统盘腔结构一维非定常计算研究的有效手段.

The main purpose is to investigate one-dimensional calculation method of cavities.The general one-dimensional modeling rule was put forward for complex cavities with nonstandard structure and multi-connections.The method of characteristics was adopted,and the one-dimensional unsteady flow and heat transfer of cavity structure was simulated.One-dimensional compressible partial differential equations of cavities generally integrating variations of variable cross section,friction and heat transfer were transformed to ordinary differential equations,so characteristic numerical solutions of pressure,flow,temperature and other parameters along the flow direction in cavity were derived.Results were verified by commercial computational fluid dynamics software CFX.Result shows that,the method adopted for one-dimensional unsteady flow and heat transfer simulation of cavity is visual and accurate,so it＇s capable of simulating complex cavity with multi-connections.The results of the method are about 9.4% away from that of the CFX model.Thus,it can be a useful way of one-dimensional unsteady research on cavity in secondary air system.