基于动态系数的涡轴发动机平衡流形模型建模方法

Equilibrium Manifold Modeling Method of Turbo-Shaft Engine Based on Dynamic Coefficient

为明确涡轴发动机动态系数模型建模机理,以线性模型为基础,通过分析状态变量对不同参数的影响,建立简化的传递函数模型。将传递函数转换成状态空间形式,推导出动态系数法模型的平衡流形展开形式,确定了建模要素。进行离散化分析,结合平衡流形原理,获取了分别基于加减速试验和阶跃辨识试验求取动态系数的方法,根据试验数据计算出动态系数,并分析了两种方法计算结果的一致性。最后对模型精度进行验证,结果表明所采用的动态系数计算及建模方法是正确的,模型稳态误差<1%,动态误差<4%,能够满足工程需要。

In order to acquire the dynamic coefficient modeling mechanism of turbo-shaft engine,based on the linear model,the simplified transfer function model was established by analyzing the effect of state variables on different engine parameters.According to the transformation from transfer function to state space equation,the equilibrium manifold expansion of dynamic coefficient method was derived,and then the modeling elements were confirmed.What is more,through combining discretization analysis with equilibrium manifold theory,the calculation method of dynamic coefficient was achieved based on acceleration-deceleration and step identification test data respectively.Finally,the consistency of dynamic coefficients calculated from two kinds of test data mentioned above,and the precision of model were verified.The results show that the dynamic coefficient calculation and modeling methods are right,the steady simulation error is less than 1%and the dynamic simulation error is less than 4%,which is suitable for engineering application.