航空发动机整机动力学建模及模型确认

Dynamic modeling and model validation of assembled whole aero-engine

关键词:  航空发动机  超模型  动力学建模  连接结构  模型确认

Key words:  Aero-engine  Supermodel  Dynamic modeling  Joint structure  Model validation

摘要:

针对航空发动机整机结构部件多、连接状态复杂、动力学特性预测困难的问题，提出了基于“超模型”虚拟测试数据的航空发动机整机结构分层次动力学建模及模型确认方法。建立各单个部件的简化模型，在初始无样机时，基于超模型的虚拟测试数据对单个部件简化模型进行动力学模型确认；基于两两连接部件超模型的虚拟测试数据，实现确认后的简化模型两两连接界面的修正与确认，连接部件超模型的虚拟测试数据通过部件的超模型与螺栓连接超模型建模理论获得；建立转子组件的动力学模型，并基于参考数据进行修正与确认；将确认后的转子模型和考虑连接的机匣系统模型进行组合，获得整机动力学模型。以某型涡扇发动机为例，采用该方法建立了其整机动力学模型。确认后的发动机整机简化模型的临界转速预测值与实际发动机整机测试的临界转速参考值对比，误差在10%以内，验证了方法的有效性。

Abstract:

A hierarchical dynamic modeling and model validation method based on ‘supermodel’ is proposed to address the difficulties in predicting the dynamic characteristics of whole aero-engine assembly structures， which have many components and complex joints. Each individual component is modeled， and based on the virtual test data of the supermodel， each component’s model is verified and validated when there is no prototype. Based on the virtual test data of the supermodel of the two connected components， the verification and validation of the connection interface of the simplified model is achieved. The virtual test data of the connected component supermodel is obtained through the both modeling theories of the supermodel whether considering individual components or joints. The dynamic model of the rotor assembly is established and validated based on reference data. The validated models of rotor and casing system considering the joints are combined to obtain the dynamic model of the whole engine. Taking a turbofan engine as an example， the whole engine dynamic model is built in this approach. The prediction of the dynamic characteristics of the validated whole engine simplified model are in agreement with the test data from the actual engine， with the errors of rotors’ critical speeds less than 10%.